Venous disorders as an occupational disease – a systematic review on epidemiology, pathophysiology, and modification strategies.

Summary: Forced postures are common in the workplace. Work in the primary economic sector is characterised by a high degree of physical activity and movement; however, activities in the secondary and tertiary sectors commonly require workers to stand or sit. An expansion of the tertiary sector in recent decades has meant that people in industrialised and emerging economies primarily sit or stand at work. The aim of the systematic review was to identify occupational factors relating to the presence of chronic venous disease (CVD), to place these in the context of developments in the workplace, and to determine whether measures are in place to prevent CVD. We performed a systematic literature review to analyse studies assessing work-related risk factors for CVD. We searched for publications in the PubMed database, the clinic library of BG Hospital Bergmannstrost Halle, and the registry of the German Statutory Accident Insurance. Using occupation-specific keyword combinations, we identified 27,522 publications. The publications underwent an automatic and manual filtering process according to the PRISMA guidelines and 81 publications qualified for the review. Ultimately 25 studies were included in the systematic review. All of the subjects of the studies worked in the secondary and tertiary sectors. No studies looked at the relationship between venous disorders and primary sector occupations. Standing at work for more than four hours a day, repeated heavy lifting, and cumulative time working in a sitting or standing position are risk factors for the development of CVD. Sitting is less of a risk factor than standing or walking. Occupational history and the patient's activity profile are important diagnostic tools which can help confirm a diagnosis and justify treatment when findings are inconsistent. Compression therapy is the primary form of secondary and tertiary prevention. There continues to be a lack of primary preventive measures related to workplace design.

Keywords: CVD; chronic venous disease; venous insufficiency; occupational disease; profession; economy sector

Introduction

Epidemiological studies conducted in recent decades have revealed an increase in the prevalence of chronic venous disease (CVD). An epidemiological review by Madar and Widmer found a continuous rise in "medically significant varicosis" – from 6.0% of participants in 1969 to 12.1% in 1981 [[1]]. While 49.9% of the respondents in the Basel study (1959–1978) reported symptoms related to venous disease, this figure rose to 56.4% in the Bonn Vein Study (2000–2002) and to over 80% in the Vein Consult Program (VCP, 2009–2011) [[2], [4]]. The VCP is by far the largest and most up-to-date study on venous disease (encompassing nearly one hundred thousand subjects) and confirms its status as a widespread disease. The study also included cases classified as C0s according to the CEAP classification (totalling 20%). Previous studies appear to have attached little importance to this class. The C0s class includes patients with no palpable signs of CVD, but who show typical symptoms of a venous disorder.

This relatively high percentage is not surprising and is in line with the authors' experience in practicing phlebology. Despite inconspicuous duplex sonography and functional diagnostic results, a large number of patients describe having typical symptoms of a venous disorder, which is often linked in their medical history to their occupation.

In this systematic literature review, the authors investigate whether there is evidence of a correlation between the increase in the prevalence of CVD and the changes occurring in the economic sectors. A systematic literature review was conducted to answer the following questions:

• 1. Which work-related risk factors are linked to the development of CVD?
• 2. How has the occupational environment developed, and which occupational groups are affected?

Patients and methods

This systematic review was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) [[5]]. We followed a strict selection protocol but without specifically registering it in PROSPERO (Figure 1).

Graph: Figure 1 Prisma Flowchart.

Search strategy and data sources

A systematic literature search for articles was conducted on 18 February 2023 (PRISMA Chart, Figure 1). We searched the PubMed database, the clinic library at BG Hospital Bergmannstrost Halle, and an additional registry of the Deutsche Gesetzliche Unfallversicherung (German Statutory Accident Insurance). The following keyword combinations were entered as part of the search: vein AND occupation*, vein AND work*, vein AND job*, vein AND profession*, vein AND employee*, venous AND occupation*, venous AND work*, venous AND job*, venous AND profession*, venous AND employee*, varicose AND occupation*, varicose AND work*, varicose AND job*, varicose AND profession* and varicose AND employee*. We decided against doing a search for subject headings (Medical Subject Headings-MeSH) because many articles would have been missed due to delayed database updates.

The following selection criteria were automatically applied for each database search: articles in English or German, full text available, keywords appear in the title. Furthermore, the articles were not to deal with thromboembolic complications (NOT thromb*), and no reviews, guidelines or meta-analyses were to be included (NOT review, NOT guideline, NOT meta-analysis). Two independent reviewers (TH and UW) screened the titles, abstracts, and full texts of the literature in each database to determine eligibility. After reading the titles and abstracts, articles with the follow characteristics were excluded: meta-analysis, review, guideline, manuscript contains the word stem thromb*, no risk factor analysis, no subdivision of the occupational groups, therapeutic issues, and case reports. This search strategy was repeated after reading the full texts.

Data extraction

The following data was extracted from each included study: study author, year of publication, journal of publication, country and study design, overall number of participants, number of participants broken down by sex, economic sector, occupational category (profession), CEAP classification, identified work-related risk factors for CVD (chronic venous disease), evidence for parameters, and identified non-work-related risk factors for CVD.

Results

Study selection

27,510 publications from the PubMed database and 12 publications from the clinic library at BG Hospital Bergmannstrost Halle and the registery of the German Statutory Accident Insurance were identified for a total of 40,755 publications after the removal of duplicates. First 27,297 records were excluded by automated tool because they were written in a language other than English or German, no full text was available, or no keyword appeared in the title. Two independent reviewers (TH and UW) conducted two rounds of filtering using the criteria mentioned in the methodology section. Ultimately, 25 publications were included in the analysis.

The 25 identified studies are listed in Table I [[6], [8], [10], [12], [14], [16], [18], [20], [22], [24], [26], [28], [30]]. They include smaller studies with fewer than one hundred subjects, as well as registries with several hundred thousand participants. The studies were published between 1955 and 2021 and represent research findings from various continents: 15 studies from Europe (mostly Denmark and Poland), 8 studies from Asia and the Middle East (mostly Korea and Iran), 2 studies from Africa and 1 study from South America. There are no studies from North America, Australia-Oceania, or Antarctica. The publication journals were predominantly public health or occupational health journals. Two studies were published in an angiology journal and one study in a phlebology journal. Only two working groups published a long-term study. The other studies were retrospective cohort studies. All studies were from the manufacturing sector (secondary economic sector: production workers, butchers, plant operators) or the service and trade sector (tertiary economic sector: nurses, kitchen workers, cleaners, hairdressers, doctors). None of the studies included workers from the primary economic sector. The evidence level according to the Oxford Centre for Evidence-Based Medicine was 3 and 4 [[31]].

Graph

Table I Presentation of the main results

Study, [reference], country (year)	1) Study design,	1) Number of participants (sex)	Identified work-related risk factors for CVD	Effect size and p-value of identified work-related risk factors	Identified non-work-related risk factors for CVD with significant effect size
	2) Evidence Level EbM [31]	2) Classification CVD (outcome)
		3) Occupational category (I, II, III) and professions
Notes. 95% CI: 95% confidence interval; I: primary sector of the economy; II: secondary sector of the economy; III: tertiary sector of the economy; BC: blue-collar occupations [jobs required manual labor]; CVD: chronic venous disease; D: diverse; EbM: evidence-based medicine; F: females; HR: hazard ratio; M: men; N: number; N/A: not available, OR: odds ratio; p: p-value; PC: pink-collar occupations [entertainment, sales, service-oriented work, a.o.]; p.h.: per hour; RR: relative risk; W: women; WC: white-collar occupations [performing professional, managering, administrative work, a.o.].
Kirsten [6] Germany (2021)	1) Observational, retrospective, cohort study	1) N=19,104 (M=9,840, F=9,264)	Working indoor	p<0.001	Pregnancies, sex (male)
	2) Level 4	2) CEAP: C0–C6	Standing	OR 1.300 (95% CI 1.076–1.571), p=0.007
		3) II/III: car manufacturing, metal processing, chemical processing/laboratory, bank agents, insurance agents	Physical strain	OR 1.262 (95% CI 1.118–1.424), p<0.001
Elamrawy [7] Egypt (2021)	1) Observational, case control	1) N=300 (M=142, F=158)	Frequent lifting of heavy objects	OR 59.57 (95% CI 6.01–584.36), p<0.001	Age, smoking, obesity, infrequent/no consumption of fiber-rich food, irregularity of defecation, drinking <5 cups of water/day
	2) Level 4	2) CEAP: C0–C6	Standing >4h/day	OR 3.65 (95% CI 1.63, 8.17), p<0.01
		3) II/III: BC, WC, PC	Sleeping <8h/day	OR 2.86 (95% CI 1.14–7.16), p=0.02
			Standing posture (>50% of the shift)	OR 3.10 (95% CI 1.02–9.31), p=0.04
Ƚastowiecka-Moras [8] Poland (2020)	1) Observational, retrospective cohort study	1) N=500 (M=238, F=262)	Lifting and carrying heavy subjects	All p<0.05	High BMI, smoking, fast food consumption, pregnancies
	2) Level 4	2) CEAP: C1–C4	Sitting >4 h/day
		3) II/III: service, health care, trade, education, industrial processing	Forced position in performing duties
			Use of large leg strength
			Fast-paced work
			Computer work
Jung [9] Korea (2020)	1) Observational, retrospective, cohort study	1) N=225,824 (M=94,700, F=131,124)	BC: standing >4 h/day >walking >sitting	p=0.08 for M (walking = standing)	Sex (female), age
	2) Level 4	2) CEAP: C3–C6		p<0.001 for F
		3) II/III: BC, WC	WC: standing >sitting (no group "walking")	p=0.76 for M
				p<0.001 for F
Shakya [10] Nepal (2020)	1) Observational, retrospective, cohort study	1) N=181 (F=181)	Standing 4–5 h/day	OR 27.44 p.h. (95% CI 4.09–180.77), p<0.00	Age, pregnancies, irregular bowel habit, education, family history
	2) Level 4	2) CEPA: C0–C4a	Standing ≥3 h/day	OR 8.8 p.h. (95% CI 2.2–35.8), p<0.001
		3) III: nurses	Sitting (mean 2 h/day)	OR 2.6 per hour (95% CI 0.48–14.04), p=0.27
Rosati [11] Italy (2019)	1) Observational, retrospective cohort study	1) N=173 (M=57, F=116)	Standing position >50% of the shift	p=0.000	Sex (female), family history, pregnancies, age
	2) Level 4	2) CEAP: C0/1–C2/3
		3) III: nurses, support stuff, employees in hospital
Yun [12] Korea (2018)	1) Observational, retrospective cohort study	1) N=421 (M=7, F=407)	Standing ≥4 h/day	OR 2.80 (95% CI: 1.08–7.25), p<0.05	Age, pregnancies
	2) Level 4	2) Duplex sonography: venous reflux >0.5 sec.
		3) III: nurses	Sitting ≤ 4 h/day	OR 0.58 (95% CI 0.27–1.21), p N/A
Diken [13] Turkey (2016)	1) Observational, retrospective cohort study	1) N=232 (M=48, F=184)	Work duration ("length of stay per day")	p=0.009	N/A
	2) Level 4	2) CEAP: C0–C4
		3) III: nurses
Ebrahimi [14] Iran (2015)	1) Observational, retrospective cohort study	1) N=197 (F=197)	Standing >3 h/day	OR 2.34 (95% CI 1.05–5.22), p=0.038	Age, family history, high blood pressure, pregnancies
	2) Level 4	2) CVD: none, mild, moderate, serve
		3) III: hairdressers
Chen [15] Taiwan (2014)	1) Observational, retrospective cohort study	1) N=182 (M=15, F=166, D=1)	Working years in total	p=0.005	Family history, age, standing housework
	2) Level 4	2) Diagnosis varicose vein	Working years 23–33 y (≤ 45 y old)	OR 2.7 (95% CI 0.0–10.2), p >0.05
		3) III: hairdressers	Working years 31–42 y (>45 y old)	OR 10.9 (95% CI 1.6–73.8), p<0.05
			Standing h/month in total	p=0.008
			Standing 261–360 h/month (>45 y old)	OR 31.8 (95% CI 1.8–566.5), p<0.05
			Standing 261–360 h/month (≤45 y old)	OR 5.2 (95% CI 0.4–75.8), p>0.05
Bašić [16] Croatia (2014)	1) Observational, case control study	1) N=120 (M and F not clearly specified)	Standing position	p=0.119 for hyperpigmentation	N/A
	2) Level 4	2) CEPA: C2–C4		p=0.153 for oedema
		3) III: doctors of dental medicine, other professions
Tabatabaeifar [17] Denmark (2014)	1) Observational, longitudinal cohort study	1) N=38,036 (M=16,259, F=21,777)	Standing/walking ≥6 h/day	HR 3.17 (95% CI 2.06–4.89), p<0.001 for M;	Age (men), pregnancies
	2) Level 3	2) Operation of varicose veins		HR 2.34 (95% CI 1.72–3.19), p<0.001 for F
		3) II/III: BC, WC	Cumulative lifting ≥1000 kg/day	HR 3.95 (95% CI 2.32–6.73), p<0.001 for M;
				HR 2.54 (95% CI 1.95–3.31), p<0.001 for F
Kohno [18] Japan (2014)	1) Observational, retrospective cohort study	1) N=318 (M=113, F=205)	Standing ≥5 h/day	OR 1.96 (95% CI 1.03–3.70), p=0.040	Obesity, sex (female), age, obesity
	2) Level 4	2) CEAP C1–C3	Standing ≥5 h/day and BMI ≥23 kg/m2	OR 3.92 (95% CI 1.21–7.51), p=0.018
		3) General population ≥45 y (occupational category N/A)	Standing ≥5 h/day and BMI ≥25 kg/m2	OR 3.42 (95% CI 1.07–10.89), p=0.038
Nia [19] Iran (2014)	1) Observational, retrospective cohort study	1) N=203 (M=58, F=145)	Standing >4 h/day	OR 3.8 (95% CI 1.2–11.9), p=0.021	Sex (female), age, obesity, bowel movement
	2) Level 4	2) CEAP C0–C3	Sitting >4 h/day	OR 1.6 (95% CI 0.5–4.9), p=0.435
		3) III: nurses
da Luz [20] Brasil (2013)	1) Observational, retrospective cohort study	1) N=14 (F=14)	Standing (still or walking) >7h	83.5%	Obesity, family history
	2) Level 4	2) CEAP C0s–C3	Lifting (>10kg)	N/A
		3) III: food service (cooking, cleaners, preparation of coffee/desserts)	High temperature (22.7–30–36.6 °C)	N/A
			Humidity (mean 55.8%)	N/A
SudoƗ-Szopińska [21] Poland (2011)	1) Observational, retrospective cohort study	1) N=126 (M=47, F=79)	Standing>sitting	p=0.015	Sex (female), age
	2) Level 4	2) CEAP C0–C5
		3) III: office worker, operators of photocopiers, laboratory workers
SudoƗ-Szopińska [22] Poland (2007)	1) Observational, retrospective cohort study	1) N=160 (M=63, F=97)	Standing (>6h/day) >sitting (>6h/day)	p=0.0145	Obesity, family history, pregnancies
	2) Level 4	2) Duplex sonography: venous reflux >0.5 sec.
		3) III: office worker, bakery
Tüchsen [23] Denmark (2005)	1) Observational, longitudinal cohort study	1) N=5,647 (M=2,939, F=2,708)	Standing/walking (>1/4 of working time)	RR 1.78 (95% CI 1.19–2.68)	Sex (female), pregnancies
	2) Level 3	2) Hospitalization with diagnosis of varicose veins
		3) General population (18–59 years)
Lacroix [24] France (2003)	1) Observational, retrospective cohort study	1) N=2,190 (M=586, F=1,604)	Sitting	OR 0.67 (95% CI 0.52–0.87), p=0.03]	Sex (female), age, obesity, family history, pregnancies, history of leg injury
	2) Level 4	2) Widmer Class 0–III
		3) General population 15–65 years (occupational category N/A)
Kontošić [25] Croatia (2000)	1) Observational, retrospective cohort study	1) N=1,324 (M=530, F=794)	Standing	OR 1.35 (95% CI 0.95–1.92), p<0.05	Age, sex (female), family history, obesity, flat feet
	2) Level 4	2) CEAP C1–C4	Heavy lifting (W>15 kg, M>25 kg)	OR 1.29 (95% CI 1.01–1.64), p<0.005
		3) II/III: catering and trade employees, office worker, industry workers	Working indoor	OR 1.61 (95% CI 1.02–2.53), p<0.01
Tüchsen [26] Denmark (2000)	1) Observational, longitudinal cohort study	1) N=5,940 (M/F N/A)	Standing>75% of working time	RR 1.85 (95% CI 1.33–2.36) for M; RR 2.63 (95% CI 2.25–3.02) for F	Age, sex (female), smoking, social groups (e.g. unskilled workers)
	2) Level 3	2) Hospitalization with diagnosis of varicose veins
		3) General population 20–59 years (occupational category N/A)
Tomei [27] Italy (1999)	1) Observational, retrospective cohort study	1) N=336 (M=336)	Standing ≥50% of working time	p=0.00001	Age, history of CVD
	2) Level 4	2) CEAP: C1–C5
		3) II/III: industrial workers, stoneworkers, office workers
Krijnen [28] Netherland (1997)	1) Observational, retrospective cohort study	1) N=387 (M=387)	Working years of standing (>80% of working time on 1 m2)	p<0.05	Age, high body weight
	2) Level 4	2) CEAP C1–C5
		3) II/III: meat industry workers, shoe factory workers, flower-packing workers, foam rubber factory workers, flower auction workers, print office worker, processing perplexes workers
Mekky [29] England/Egypt (1969)	1) Observational, retrospective cohort study	1) N=971 (F=971)	Standing position	p<0.001	Pregnancies, age, body weight
	2) Level 4	2) CVD: visible varicose veins
		3) II: cotton workers
Steward [30] England (1955)	1) Observational, retrospective cohort study	1) N=48,908 (M=48,908)	Standing position	p<0.001	High body height, high body weight, body build (too tall for their weight)
	2) Level 4	2) CVD: visible varicose veins
		3) General population <45 y (occupational category N/A)

Main findings

Standing, especially for more than 4–6 hours per day at work was assessed as an independent risk factor for the development of CVD in most studies (Figure 2) [[7], [9], [11], [14], [17], [19], [22], [27]].

Graph: Figure 2 Forest plot: Effect size "standing" with (95%) confidence interval as a work-related risk factor for CVD.

The data showed no correlation between sedentary behaviour and the development of varicose veins in men; however, it did show a correlation between the number of years worked and the severity of the CVD [[15]]. Several studies showed that women who sat or stood at work for an average of six or more hours had a significantly higher risk of developing varicose veins than women who worked four or fewer hours in these forced postures [[7], [17]]. In contrast, a large German population-based observational study of over 19,000 employees from various branches of the secondary and tertiary economic sectors came to the conclusion that being female was a protective factor against the development of CVD (odds ratio [OR] 0.66, 95% Confidence Interval [95% CI] 0.59–0.73). According to the trial, 22.3% of adult workers in Germany have a clear indication for active vein treatment [[6]]. Lacroix et al. were even able to demonstrate in the population they studied that sitting at work could have a protective effect against developing CVD compared to work that required standing (OR 0.67, 95% CI 0.52–0.87) [[24]].

Several studies found a correlation between the weight of occupational loads (>10 kg, up to a cumulative 1,000 kg, >20 kg, ≥¼ of working time, women >15 kg, men >25 kg) and the development of venous disease. A clear, gender-specific weight limit could not be determined [[7], [17], [20], [25]].

Some studies showed an increase in CVD in subjects who worked indoors or in a work environment with high room temperatures [[6], [20], [25]].

A Danish study by Tüchsen et al. on more than 5,500 randomly selected men and women came to the conclusion after an observation period of 12 years that the relative risk of requiring varicose vein surgery on an inpatient basis increased 1.78 times when the patient predominantly had to stand or walk around at work [[23]]. Two study groups did not clearly distinguish between standing and walking in their determination of effect size, although a significant effect was seen. It was therefore not possible to determine which forced posture caused the effect [[17], [23], [26]]. Also, in the study by Jung et al. on male, blue collar workers, walking and standing were shown to be equal risk factors [[9]].

Chen et al. found that the prevalence of CVD in hairdressers increased the longer they worked (30.5 vs. 24.0 years, p=0.005) [[15]]. In contrast, Tomei et al. did not see this effect [[27]].

Most studies identified the known non-work-related risk factors for CVD such as: age, female sex, number of pregnancies, obesity, smoking, family history.

Discussion

A recent review by Costa et al. examined the social factors that determine the vascular health of the population. While socioeconomic status, ethnicity and sex play a decisive role in the development of arterial diseases, such as peripheral artery disease, abdominal arterial aneurysm and carotid stenosis, the studies included in the review show that working conditions and type of profession are critical for the development of venous disease [[32]]. In economics, a distinction is made between three types of sectors: the primary sector of commodity production (e.g., fishing, agriculture, mining), the secondary sector of manufacturing and production (e.g., industry, construction, trades, energy) and the tertiary sector, which includes services and information technology (e.g., trade, transport, IT, tourism, consulting, healthcare). Forced postures are common to most professions. While jobs in the primary sector of the economy, "primary production", involve physical activity with a high degree of movement, the secondary and tertiary sectors of the economy are dominated by work carried out in a standing or seated position. In recent decades there has been a significant change in the world's economies. Above all, the expansion of the tertiary sector in industrialised and emerging countries has resulted in a change in occupation-related forced postures. The distribution of the economic sectors varies from country to country and depends on a nation's economic strategy. Nevertheless, most jobs are in the secondary and tertiary sectors, in which people predominantly sit or stand at work (Figure 3) [[33], [35], [37], [39]]. As in most countries, the percentage of white-collar workers in Germany's tertiary sector has more than doubled – from 32.7% in 1951 (excl. the GDR) to 74.9% – whereas the share of blue-collar workers in the primary sector of the economy has fallen from 23.1% to 1.2% [[41]]. The data from the epidemiological studies cited in the introduction show that the prevalence of venous disease increased in the 20th century. The studies presented here indicate a correlation between economic development and the presence of venous disease.

Graph: Figure 3 Growth of the tertiary economic sector since 1950 [[2], [4], [33], [35], [37], [39], [41]]: (A) There are 3 economic sectors: the primary sector of raw material production (black), the secondary manufacturing sector (dark grey) and the tertiary service sector (light grey). While the primary economic sector is characterized by a high level of physical activity, standing, and sitting activities dominate the secondary and tertiary sectors. (B) The dominant increase of the tertiary sector is connected to an increase of the prevalence of the CVD.

The analysed studies showed that it is not a specific occupational group that is affected by venous disease, but rather that occupational circumstances such as standing, length of time standing, and ambient temperatures can be factors in the occurrence of CVD. It should be noted that the subjects of all of the studies came from the secondary and tertiary sectors of the economy; studies on the relationship between venous disorders and occupational groups in the primary economic sector were not available. This supports the hypothesis that venous disorders are a phenomenon of the secondary and tertiary economic sectors, although it cannot be completely ruled out that occupational groups in the primary economic sector, who are exposed to forced postures, can also develop venous disorders. It can, however, be assumed that workers who produce raw materials commonly have a high proportion of movement when working.

Studies have shown the detrimental effect that standing has on venous haemodynamics, with sitting having no relevant effect. In addition to pressure changes related to posture, venous haemodynamics are maintained through the action of the calf muscle and foot pump. In a recent experimental study, Junge et al. were able to demonstrate a correlation between standing in a workplace setting and the development of a measurable degree of leg swelling and discomfort [[42]]. In their experimental study on healthy volunteers, Lastowiecka-Moras et al. used photoplethysmography to show that venous refilling time changed pathologically after 20 minutes of standing, while sitting for 20 minutes with knees bent at 90° produced no pathological changes [[43]]. Antle et al. investigated how sitting or standing for 34 minutes changed the venous blood flow in the foot and in the area of the soleus muscle. They found that standing resulted in an average volume increase in the foot (+77%) and in the soleus muscle (+55%) compared to sitting. These results demonstrate that the absence of movement when standing can result in a drastic deterioration of venous haemodynamics, even in vascularly healthy individuals [[44]].

An important functional mechanism for venous haemodynamics is the effect of the musculoskeletal apparatus of the leg and foot. Stranden investigated venous pressure in the foot in relation to the position of the body. Pressures were around 5 mmHg when lying down and 5–10 times higher than this when standing. Venous pressure was highest when standing, ranging from 75 to 90 mmHg depending on body size. Under physiological conditions, venous haemodynamics when walking lower venous pressure to 25 to 30 mmHg [[45]]. The calf muscle foot pump is the most important extravascular functional unit for venous return. The calf muscle pump can be divided into a proximal and a distal section. The proximal section mobilises venous blood through local muscle contractions in all muscle compartments of the lower leg on plantar flexion of the foot. The distal section functions through muscle displacement distally (piston effect) on dorsiflexion of the foot. The physiological mechanisms of the calf muscle foot pump become clear when observing the gait cycle. Using airplethysmography, Lattimer et al. found that the largest venous blood volumes (123 ml, p<0.0005) were transported when body weight was transferred to one leg (ankle pivot point). Significantly lower blood volumes were mobilised when standing on tiptoe at the end of the stance phase and in preparation of the swing phase (69 ml) and on dorsiflexion of the foot in the swing phase (54 ml). The venous foot pump was identified here as an important mechanism for mobilising blood volumes (40% increased ejection fraction in the veins compared to standing on tiptoe). Although dorsiflexion of the foot, in contrast to the tiptoe manoeuvre (flexor compartment – many venous segments), only activated the extensor compartment (few venous segments), the two manoeuvres were equivalent due to the "piston effect" [[46]]. A study by Broderick et al. on five healthy women and five healthy men examined the significance of shifting body weight, toe scrunches and compression devices (IPC, neuromuscular electrical stimulation) for emptying the veins of the foot. The weight-bearing and toe scrunching manoeuvres were also simulated when lying down. Venous emptying was most effective with a shifting of body weight and toe scrunches in a standing position; the two manoeuvres did not differ significantly [[47]].

The epidemiological studies also confirm that, while sitting is associated with an increased risk of developing symptoms of venous disease, standing is a stronger risk factor. In theory, it can be assumed that this pressure load - in addition to venous stasis with indication of inflammatory processes - also leads to a pressure load in the venous valve sinus and, over time, to venous insufficiency. However, there are no studies to support this theory.

The only prospective studies on this topic were conducted by Tüchsen and Tabatabaeifar. A cohort of 1.6 million working Danes was observed over 3 years (1991–1994) and analysed for risk factors that led to the hospitalised treatment of varicose veins. For men with a risk for long standing/walking time (>3/4 of work time), the adjusted relative risk was 1.85 (95% CI 1.33–2.36) vs 2.63 (95% CI 2.25–3.02) for women. Furthermore, the data also suggest that this risk is not lowered by the type of walking that is typical in the workplace. Several studies come to this conclusion without providing a physiological explanation [[9], [17], [23], [26]]. One conceivable explanation is that the activation of the muscle and joint pump over short walking distances as part of a typical work routine does not compensate for the increase in ambulatory venous pressure as a result of the permanent effects of gravity. It can be assumed that the effect of the hydrostatic pressure must trigger the pathophysiological mechanism, since long periods of standing as well as long periods of walking turned out to be a risk factor in these test subjects, despite the fact that walking should have a physiologically positive effect on venous haemodynamics by reducing venous pressure. One conceivable explanation is that the activation of the muscle and joint pump over short walking distances as part of a typical work routine does not compensate for the increase in ambulatory venous pressure as a result of the permanent effects of gravity.

Reducing standing time and increasing sitting time in daily working life are not recommended. Occupational exposure to sitting is associated with an increased risk of cardiovascular disease, diabetes mellitus, tumours and obesity. Studies have even found a correlation between sitting time and an increased mortality rate [[48], [50]]. A survey conducted in 2021 by the German health insurance companies found that respondents sat an average of 8.5 hours per day, which had increased by one hour since 2018. Most of the sitting (33%) occurred at work, with 57% of respondents sitting for at least 8 hours per day [[51]].

Prevention studies in the workplace have therefore focused exclusively on reducing sedentary behaviour [[52]]. The research group of Backe et al. investigated workplace intervention measures to reduce sitting time and defined four areas of intervention (Figure 4) [[53]]. The intervention level "workplace environment" included seated and standing workstations, dynamic workstations or a "movement-promoting office building" whose architecture or interior design encourages movement (e.g., internal walkways, strategic placement of office equipment, etc.). Individual measures are a second level of intervention which include advice for employees from the company physician or a coach. One very important aspect was providing employees with information about possible harms to their health. Furthermore, emails or PC prompts were able to remind workers to actively move around. The third level of intervention, work organisation, included the expansion of human resources and the restructuring of the work culture (e.g., meetings conducted while standing). Modifications to the workplace environment and individual intervention measures reduced sitting time by around 33-35 minutes after 8–12 weeks with a moderate degree of evidence (= consistent results in one study with a low risk of bias and one study with a medium or high risk of bias, or consistent results in several studies with a medium or high risk of bias). The "movement-promoting office building" also only produced moderate evidence, which was confirmed by other studies [[55]]. Despite moderate evidence, the studies found that multi-component intervention led to the highest reduction in sitting time by 48 minutes/day after 3 months.

Graph: Figure 4 Starting point for intervention strategies in the workplace. Three levels of intervention can be distinguished: the working environment (e.g. sitting/standing workstations, dynamic workplaces, office design that encourages physical activity), the individual measures (e.g. training, advice, medical information, app or PC-based information) and the work organization (e.g. creating free time, changing work culture). The multi-component approach combines all approaches.

All of the workplace intervention measures studied aimed to reduce sitting time in favour of time spent standing or walking within a small radius. Knowledge of the pathophysiological causes for the development of venous disease means that these measures are not recommended. An occupational health database related to the topic of veins and occupation does not yet exist.

Compression therapy is an essential form of therapy for secondary and tertiary prevention. Medical compression stockings (MCS) commonly have a compression intensity that corresponds to classes 1 (18–21 mmHg) and 2 (23–32 mmHg) [[56]]. Pressure distribution is graduated, i.e., the maximum pressure of the compression stocking is in the ankle region (B1). There are also non-graduated compression stockings where the maximum pressure occurs in the calf area. Blättler et al. investigated the effect of MSC in individuals with healthy veins after 10 minutes of standing. Leg volume decreased as compression pressure increased (no compression=leg volume +44 ml when standing, 10–15 mmHg MCS=+32 ml p<0.001, 23–32 mmHg MCS=+24 ml p<0.001, difference between 10–15 mmHg and 23–32 mmHg MCS, p=0.06). However, there was no correlation between a lessening of symptoms and compression pressure or a reduction in leg volume. The only decisive factor in symptom improvement was the fact that a compression stocking was worn at all. There was no difference between compression classes 1 and 2 [[57]]. Another study compared the effects of non-graduated compression stockings on leg volume when sitting still and when seated with foot movement. The result was that leg volume is reduced with compression when seated (without compression +76 ml and with compression +56 ml p<0.01). This neither positively nor negatively affected the functionality of the foot and calf muscle pump [[58]]. Other studies showed a greater effect of 20–30 mmHg MCS when seated compared to standing, or when alternating between sitting and standing. For 15–20 mmHg MCS, the effect was the same when standing and sitting [[59]]. A compression pressure of 10–15 mmHg is enough to effectively reduce leg oedema and discomfort. Lower compression pressures are ineffective and higher compression pressures are not proven to be more effective [[60]]. However, in a study by Hecko et al., compression pressures of 8–10 mmHg were also enough to reduce orthostatic oedema and alleviate venous symptoms [[61]]. Graduated and non-graduated compression stockings significantly reduce leg volumes. However, this reduction (mainly in the calf muscle area and not in the ankle area) was significantly higher with non-graduated compression stockings (+ 20 ml) than with graduated compression stockings (+ 40 ml) [[62]]. Thus, the use of an MCS with a compression class of 1, or even a non-graduated compression stocking, is recommended to prevent occupation-related, stage C0s venous symptoms. MCSs improve the quality of life for patients with chronic venous disease and serve to prevent and treat venous oedema [[63]].

However, there are currently no studies that prove the prophylactic effect of medical compression stockings on the development and progression of chronic venous disease. Compression therapy is used to relieve symptoms and heal ulcers [[64]]. However, due to the physiological and pathophysiological mechanisms involved in the development of CVD, the authors also consider prophylactic compression therapy to be sensible and worth investigating in exposed occupational groups. Venous medications can also be used. Studies have shown that red vine leaf extract and oxerutin significantly reduce symptoms such as leg pain, leg swelling and tightness [[65], [67]].

Limitations

The main limitation is the inconsistency of the study data, since they stem from different decades. Not only have there been changes to the economic sectors, medical definitions have also changed. One defined target criterion in all studies was inquiring about typical venous symptoms; however, the clinical classification varied (clinical signs or Widmer classification or CEAP classification). Several studies found "standing >4h/day" to be a work-related risk factor; but most of the results were too heterogeneous and therefore a quantitative evaluation was not possible. This meant that only a qualitative assessment could be made. This was because predominantly descriptive studies, such as cross-sectional studies or case-control studies, were filtered out. Therefore, no intra-individual changes or developmental trajectories could be witnessed in connection with occupational activity. In addition to surveys and examinations, register data and coding before illness were also used in the data collection, which disrupted the consistency of the data. Also, the influence of non-occupational exposure to forced postures was not considered in the cited studies. To avoid confounders in the observational studies, a statistical treatment would have been necessary, which was not carried out. A selection bias or publication bias cannot be ruled out either. In addition to the well-known confounders, such as non-modifiable risk factors (age, gender, pregnancy, genetics), there are also modifiable risk factors (obesity, nicotine consumption) and conditionally modifiable risk factors (foot deformities, noticeable lack of movement amplitudes in the leg joints, muscular restrictions in the leg area). The studies cannot clarify whether the connection between prolonged standing and the development of CVD is causal. Randomised trials could greatly increase the homogeneity of the data; however, the authors doubt whether it is possible to conduct randomised studies to determine the risk of developing venous disease through occupational exposure. Here, further observational studies in different sectors of the economy would be necessary, with biased results avoided through sound static evaluation.

Conclusions

Working while standing up for more than four hours a day, repetitive lifting of heavy loads, and cumulative working time spent sitting and standing are risk factors for developing chronic venous disease from workplace conditions. One surprising result is that sitting appears to play a subordinate role. The physiological mechanisms do not explain some of the study results. Hence, hydrostatic changes could play an important role. A significant finding can be made with respect to the very heterogenous nature of the available studies that focus on venous disorders under the aspect of occupational exposure. A patient's occupational history and an analysis of the patient's activities are considered important diagnostic tools that can help confirm a diagnosis. They can also justify treatment when the results of the Duplex sonography and phlebological functional diagnostics are ambiguous.

Compression therapy using medical compression stockings (MCS) is the main therapeutic approach in secondary and tertiary prevention and should be used at an early stage (class C0s).

A greater importance must be placed on primary prevention measures. The authors do not recommend changing the workplace per se, but rather modifying the workplace environment and expanding the awareness of individuals. Not only the physicians practising phlebology, but also the professional societies and associations have a duty to make employers and those affected aware of the significance of venous disorders and thus establish intervention strategies in the workplace. Future studies should investigate a more precise definition of fixed and dynamic standing time and focus on the male sex, as men have a lower prevalence for chronic vein insufficiency and thus few confounders.

Conflicts of Interests: No conflicts of interest exist.

1 Madar, G, Widmer, LK. Varicosis und chronisch venöse Insuffizienz – geringfügige Gesundheitsstörung oder Krankheit? Eine kritische LiteraturübersichtPhlebol Proktol. 1990;19:69–79. 2 Widmer, LK, Stählin, HB, Nissen, C, da Silva, A. Venen-, Arterien-Krankheiten, koronare Herzkrankheit bei Berufstätigen: prospektiv – epidemiologische Untersuchung. Basler Studie I–III 1959–1978. Bern; Stuttgart; Wien: Verlag Hans Huber. 1981:61–134. 3 Rabe, E, Pannier-Fischer, F, Bromen, K, Schuldt, K, Stang, A, Poncar, C, et al.. Bonner Venenstudie der Deutschen Gesellschaft für Phlebologie. Epidemiologische Untersuchung zur Frage der Häufigkeit und Ausprägung von chronischen Venenkrankheiten in der städtischen und ländlichen Wohnbevölkerung. Phlebologie. 2003;32:1–14. 4 Rabe, E, Guex, JJ, Scuderi, A, Quesada, FF, for VCP Coordinators. Epidemiology of chronic venous disorders in geographically diverse populations: results from the Vein Consult Program. Int Angiol. 2012;31:105–15. 5 Page, MJ, McKenzie, JE, Bossuyt, PM, Boutron, I, Hoffmann, TC, Mulrow, CD, et al.The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. 6 Kirsten, N, Mohr, N, Gensel, F, Alhumam, A, Bruning, G, Augustin, M. Population-based epidemiologic study in venous diseases in germany – prevalence, comorbidity, and medical needs in a cohort of 19,104 workers. Vasc Health Risk Manag. 2021;17:679–87. 7 Elamrawy, S, Darwish, I, Moustafa, S, Elshaer, N, Ahmed, N. Epidemiological, life style, and occupational factors associated with lower limb varicose veins: a case control study. J Egypt Public Health Assoc. 2021;96:19. 8 Ƚastowiecka-Moras, E. Standing and sitting postures at work and symptoms of venous insufficiency – results from questionnaires and a Doppler ultrasound study. Int J Occup Saf Ergon. 2021;27:963–69. 9 Jung, S, Kim, Y, Kang, D, Kim, SY, Kim, I, Kim, EM. Distribution of working position among workers with varicose veins based on the National Health Insurance and National Employment Insurance data. Ann Occup Environ Med. 2020;32. Shakya, R, Karmacharya, RM, Shrestha, R, Shrestha, A. Varicose veins and its risk factors among nurses at Dhulikhel hospital: a cross sectional study. BMC Nurs. 2020;19:8. Rosati, MV, Sacco, C, Mastrantonio, A, Giammichele, G, Buomprisco, G, Ricci, P, et al.Prevalence of chronic venous pathology in healthcare workers and the role of upright standing. Int Angiol. 2019;38:201–10. Yun, MJ, Kim, YK, Kang, DM, Kim, JE, Ha, WC, Jung, KY, et al.A study on prevalence and risk factors for varicose veins in nurses at a university hospital. Saf Health Work. 2018;9:79–83. Diken, A, Yalçinkaya, A, Aksoy, E, Yilmaz, S, Özşen, K, Sarak, T, et al.Prevalence, presentation and occupational risk factors of chronic venous disease in nurses. Phlebology. 2016;31:111–7. Ebrahimi, H, Amanpour, F, Haghighi, NB. Prevalence and risk factors of varicose veins among female hairdressers: a cross sectional study in north-east of Iran. J Res Health Sci Spring. 2015;15:119–23. Chen, CL, Guo, HR. Varicose veins in hairdressers and associated risk factors: a cross-sectional study. BMC Public Health. 2014;14:885. Bašić, R, Rošić, D, Ledinsky, I, Lovričević, I. Orthostatics and chronic venous insufficiency in Croatian doctors of dental medicine. Acta Clin Croat. 2014;53:3–6. Tabatabaeifar, S, Frost, P, Andersen, JH, Jensen, LD, Thomsen, JF, Svendsen, SW. Varicose veins in the lower extremities in relation to occupational mechanical exposures: a longitudinal study. Occup Environ Med. 2015;72:330–37. Kohno, K, Nihara, H, Hamano, T, Takeda, M, Yamasaki, M, Mizumoto, K, et al.Standing posture at work and overweight exacerbate varicose veins: Shimane CoHRE Study. J Dermatol. 2014;41:964–68. Nia, HS, Chan, YH, Haghdoost, AA, Soleimani, MA, Beheshti, Z, Bahrami, N. Varicose veins of the legs among nurses: Occupational and demographic characteristics. Int J Nurs Pract. 2015;21:313–20. da Luz, CM, da Costa Proença, RP, de Salazar, BR, do Nascimento Galego, G. Working conditions at hospital food service and the development of venous disease of lower limbs. Int J Environ Health Res. 2013;23:520–30. SudoƗ-Szopińska, I, Bogdan, A, Szopiński, T, Panorska, AK, KoƗodziejczak, M. Prevalence of chronic venous disorders among employees working in prolonged sitting and standing postures. Int J Occup Saf Ergon. 2011;17:165–73. SudoƗ-Szopińska, I, Panorska, AK, Koziński, P, BƗachowiak, K. Work-related chronic venous disease in office and bakery workers. Occupational Ergonomics. 2007;7:125–37. Tüchsen, F, Hannerz, H, Burr, H, Krause, N. Prolonged standing at work and hospitalisation due to varicose veins: a 12 year prospective study of the Danish population. Occup Environ Med. 2005;62:847–50. Lacroix, P, Aboyans, V, Preux, PM, Houlès, MB, Laskar, M. Epidemiology of venous insufficiency in an occupational population. Int Angiol. 2003;22:172–6. Kontošić, I, Vukelić, M, Dreščik, I, Mesaroš-Kanjski, E, Materljan, E, Jonjić, A. Work conditions as risk factors for varicose veins of the lower extremities in certain professions of the working population of Rijeka. Acta Med Okayama. 2000;54:33–8. Tüchsen, F, Krause, N, Hannerz, H, Burr, H, Kristensen, TS. Standing at work and varicose veins. Scand J Work Environ Health. 2000;26:414–20. Tomei, F, Baccolo, TP, Tomao, E, Palmi, S, Rosati, MV. Chronic venous disorders and occupation. Am J Ind Med. 1999;36:653–65. Krijnen, RMA, de Boer, EM, Adèr, HJ, Bruynzeel, DP. Venous insufficiency in male workers with a standing profession. Part 1: epidemiology. Dermatology. 1997;194:111–20. Mekky, S, Schilling, RS, Walford, J. Varicose veins in women cotton workers. An epidemiological study in England and Egypt. Br Med J. 1969;2:591–5. Steward, AM, Webb, JW, Hewitt, D. Social medicine studies based on civilian medical board records. II. Physical and occupational characteristics of men with varicose conditions. Br J Prev Soc Med. 1955;9:26–32. OCEBM Levels of Evidence Working Group. "The Oxford 2011 Levels of Evidence". Oxford Centre for Evidence-Based Medicine. Available from https://www.ergo.com/de/Newsroom?result=DKV-Report-2021. Costa, D, Ielapi, N, Bevacqua, E, et al.Social determinants of health and vascular diseases: a systematic review and call for action. Soc Sci. 2023;12(4):214. Wiegmann, H. Die Entwicklung der Berufsstruktur in der Sowjetunion. In: Wiegmann, H: Die Entwicklung der Berufsstruktur der UdSSR und ihre Behandlung in der sozialwissenschaftlichen Behandlung der Sowjetunion. Veröffentlichungen des Osteuropa-Institutes München. Reihe: Wirtschaft und Gesellschaft. Heft 16. Berlin: Duncker & Humboldt Verlag. 1974. [cited 2023 Feb 18]. Available fromhttps://books.google.de/books?id=CjMvlKbtGAkC&pg=PA64&lpg=PA64&dq=prozentuale+verteilung+wirtschaftssektoren+1950+udssr&source=bl&ots=tNXNRd0lJZ&sig=ACfU3U3C15eP06jdnYA3wES2lcgMu01v7A&hl=de&sa=X&ved=2ahUKEwjEzY7Kyuj0AhVHSfEDHUbgDqwQ6AF6BAgeEAM#v=onepage&q=prozentuale%20verteilung%20wirtschaftssektoren%201950%20udssr&f=false. Wirtschaftskammer Österreich. Länderprofil Russland. [cited 2023 Feb 18]. Available fromhttps://wko.at/statistik/laenderprofile/lp-russland.pdf. Wirtschaftskammer Österreich. Länderprofil USA. [cited 2023 Feb 18]. Available fromhttps://wko.at/statistik/laenderprofile/lp-usa.pdf. Wirtschaftskammer Österreich. Länderprofil Brasilien. [cited 2023 Feb 18]. Available fromhttp://wko.at/statistik/laenderprofile/lp-brasilien.pdf. Klett. Industrie und gesellschaftlicher Wandel. In: Kreus, A, Lindner, P, von der Ruhren, N (Ed.), Fundamente Kursthemen: Industrie/Dienstleistungen. 1. Auflage. Stuttgart: Klett Verlag; 2006. p. 20–23. [cited 2023 Feb 18]. Available fromhttps://www2.klett.de/sixcms/media.php/229/29260X-6101.pdf. Worldbank. Employment in industry. [cited 2023 Feb 18]. Available fromhttps://data.worldbank.org/indicator/SL.IND.EMPL.ZS?end=2002&start=1991. Urquhart, M. The employment shift to services: where did it come from?". Monthly Labor Review. 1984;107:15–22. [cited 2023 Feb 18]. Available fromhttp://www.jstor.org/stable/41842249. Baer, W, Baer, F, Manuel, AR, et al.. Structural changes in Brazil's industrialeconomy, 1960–80. 1986. [cited 2023 Feb 18]. Available fromhttps://mpra.ub.uni-muenchen.de/54823/1/MPRA_paper_54823.pdf Statistisches Bundesamt. Erwerbstätige im Inland nach Wirtschaftssektoren. Deutschland. [cited 2023 Feb 18]. Available fromhttps://www.destatis.de/DE/Themen/Wirtschaft/Konjunkturindikatoren/Lange-Reihen/Arbeitsmarkt/lrerw13a.html Junge, F, Konschake, W, Haase, H, Vollmer, M, Jünger, M. Walking instead of standing. Influence of movement on sensations of discomfort and the volume of the lower legs during standing loads. Vasa. 2022;51:8–84. Ƚastowiecka-Moras, E. How posture influences venous blood flow in the lower limbs: results of a study using photoplethysmography. Int J Occup Saf Ergon. 2017;23:147–51. Antle, DM, Cormier, L, Findlay, M, Miller, LL, Côte, JN. Lower limb blood flow and mean arterial pressure during standing and seated work: Implications for workplace posture recommendations. Prev Med Rep. 2018;10:117–22. Stranden, E. Dynamic leg volume changes when sitting in a locked and free floating tilt office chair. Ergonomics. 2000;43:421–33. Lattimer, CR, Franceschi, C, Kalodiki, E. Optimizing calf muscle pump function. Phlebology. 2018;33:353–60. Broderick, BJ, Corley, GJ, Quondamatteo, F, Breen, PP, Serrador, J, Ólaighinet, G. Venous emptying from the foot: influences of weight bearing, toe curls, electrical stimulation, passive compression, and posture. J Appl Physiol. 2010;109:1045–52. Lavie, CJ, Ozemek, C, Carbone, S, Katzmarzyk, PT, Blair, SN. Sedentary behavior, exercise, and cardiovascular health. Circ Res. 2019;124:799–815. Biswas, A, Oh, PI, Faulkner, GE, Bajaj, RR, Silver, MA, Mitchell, MS, et al.Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults: a systematic review and meta-analysis. Ann Intern Med. 2015;162:123–32. van Uffelen, JGZ, Wong, J, Chau, JY, van der Ploeg, HP, Riphagen, I, Gilson, ND, et al.Occupational sitting and health risks: a systematic review. Am J Prev Med. 2010;39:379–88. ERGO Group. Der DKV-Report 2021 – Wie gesund lebt Deutschland?[cited 2023 Feb 18]. Available from https://www.ergo.com/de/Newsroom?result=DKV-Report-2021 Pereira, MA, Mullane, SL, Toledo, MJL, Larouche, ML, Rydell, SA, Vuong, B, et al.Efficacy of the 'Stand and Move at Work' multicomponent workplace intervention to reduce sedentary time and improve cardiometabolic risk: a group randomized clinical trial. Int J Behav Nutr Phys Act. 2020;17:133. Backe, EM, Kreis, L, Latza, U. Interventionen am Arbeitsplatz, die zur Veränderung des Sitzverhaltens anregen – Übersicht und Einschätzung. Zbl Arbeitsmed. 2019;69:1–10. Kreis, L, Backe, EM, Latza, U. Interventionen zur Reduktion des sitzenden Verhaltens am Arbeitsplatz – ein systematischer Review. ASU Arbeits med Sozialmed Umweltmed. 2018;58:798–13. Engelen, S. Does active design influence activity, sitting, wellbeing and productivity in the workplace? A systematic review. Int J Environ Res Public Health. 2020;17:9228. Kobus, S, Reich-Schupke, S. Kompressionsstrümpfe. In: Reich-Schupke, S, Stücker, M (Hrsg.): Moderne Kompressionstherapie. Ein praktischer Leitfaden. 1. Auflage. Köln: Viavital Verlag; 2013. p. 76–84. Blättler, W, Thomae, HJ, Amsler, F. Venous leg symptoms in healthy subjects assessed during prolonged standing. J Vasc Surg Venous Lymphat Disord. 2016;4:455–62. Suehiro, K, Morikage, N, Harada, T, Samura, M, Nagase, T, Takeuchi, Y, et al.Effects of leg compression and calf muscle contraction by active ankle motion on venous hemodynamics in sitting individuals. Phlebology. 2022;37:361–6. Quilici Belczak, CE, Pereira de Godoy, JM, Seidel, AC, Belczak, S, Neves Ramos, R, Caffaro, RA. Comparison of 15–20 mmhg versus 20–30 mmhg compression stockings in reducing occupational oedema in standing and seated healthy individuals. Int J Vasc Med. 2018;2053985. Amsler, F, Blätter, W. Compression therapy for occupational leg symptoms and chronic venous disorders – a meta-analysis of randomised controlled trials. Eur J Vasc Endovasc Surg. 2008;35:366–72. Hecko, S, Lutze, S, Arnold, A, Haase, H, Jünger, M, Riebe, H. Improvement of occupational leg edema and discomforts (RCT). Clin Hemorheol Microcirc. 2022;82:125–39. Mosti, G, Partsch, H. Occupational leg oedema is more reduced by antigraduated than by graduated stockings. Eur J Vasc Endovasc Surg. 2013;45:523–7. Rabe, E, Földi, E, Gerlach, H, et al.S2k-Leitlinie: Medizinische Kompressionstherapie der Extremitäten mit Medizinischem Kompressionsstrumpf (MKS), Phlebologischem Kompressionsverband (PKV) und Medizinischen adaptiven Kompressionssystemen (MAK). [cited 2023 Feb 18]. Available fromhttps://www.awmf.org/uploads/tx%5fszleitlinien/037-005l%5fS3k%5fMedizinische-Kompressionstherapie-MKS-PKV%5f2019-05.pdf Rabe, E, Partsch, H, Hafner, J, Lattimer, C, Mosti, G, Neumann, M, et al.Indications for medical compression stockings in venous and lymphatic disorders: An evidence-based consensus statement. Phlebology. 2018;33:163–84. Pannier, F, Noppeney, T, Alm, J, et al.S2k – Leitlinie Diagnostik und Therapie der Varikose. [cited 2023 Feb 18]. Available fromhttps://www.awmf.org/uploads/tx%5fszleitlinien/037-018l%5fS2k%5fVarikose%5fDiagnostik-Therapie%5f2019-07.pdf. Ramelet, AA, Boisseau, MR, Allegra, C, Nicolaides, A, Jaeger, K, Carpentier, P, et al.Veno-active drugs in the management of chronic venous disease. An international consensus statement: current medical position, prospective views and final resolution. Clin Hemorheol Microcirc. 2005;33:309–19. Barros, BS, Kakkos, SK, De Maeseneer, M, Nicolaides, AN. Chronic venous disease: from symptoms to microcirculation. Int Angiol. 2019;38:211–8.

By Tobias Hirsch; Uwe Wahl and Eberhard Rabe

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