Does influence at work modify the relation between high occupational physical activity and risk of heart disease in women?

Occupational Physical Activity and Cardiometabolic Risk Factors: A Cross-Sectional Study

Contradictory data exist on the impact of occupational physical activity (OPA) on cardiovascular health. We aimed to evaluate the association between OPA and cardiometabolic risk factors. A cross-sectional study was performed in an environmental services company in 2017 (Spain). OPA was classified by work categories as being low (≤3 METs) or moderate−high (>3 METs). Multiple linear and logistic binary regression models were used to assess the associations between OPA and cardiometabolic risk factors related to obesity, blood pressure, blood lipids, and associated medical conditions, adjusted by age, sex, alcohol consumption, and global physical activity. In total, 751 employees were included (547 males and 204 females), and 55.5% (n = 417) had moderate−high OPA. Significant inverse associations were observed between OPA and weight, body mass index, waist circumference, waist−hip ratio, and total cholesterol both overall and in males. OPA was significantly inversely related to dyslipidemia overall and in both sexes, while the overweight plus obesity rate was inversely related only in the total and male populations. OPA was associated with a better cardiometabolic risk factor profile, particularly in males. The fact that our models were also adjusted by global physical activity highlights the associations obtained as being independent of leisure time physical activity effects.

Leisure-time physical activity, occupational physical activity and the physical activity paradox in healthcare workers: A systematic overview of the literature

BACKGROUND

Physical activity positively influences cardiovascular health. Results from male-dominated physically active occupations suggest that a high level of occupational physical activity may be detrimental to cardiovascular health. This observation is referred to as the physical activity paradox. Whether this phenomenon can also be observed in female-dominated occupations remains unknown.

OBJECTIVE

We aimed to provide an overview of (1) leisure-time and occupational physical activity in healthcare workers. Therefore, we reviewed studies (2) to assess the relationship between the two physical activity domains and analyzed (3) their effects on cardiovascular health outcomes in relation to the paradox.

METHODS

Five databases (CINAHAL, PubMed, Scopus, Sportdiscus, Web of Science) were systematically searched. Both authors independently screened the titles, abstracts, and full texts and assessed the quality of the studies using the National Institutes of Health's quality assessment tool for observational cohort and cross-sectional studies. All studies that assessed leisure-time and occupational physical activity in healthcare workers were included. The two authors independently rated the risk of bias using the ROBINS-E tool. The body of evidence was evaluated using the GRADE approach.

RESULTS

The review included 17 studies that assessed the leisure-time and occupational physical activity of people working in healthcare, determined the relationship between the domains (n = 7) and/or examined their effects on the cardiovascular system (n = 5). Measurements for leisure-time and occupational physical activity varied between studies. Leisure-time physical activity typically ranged between low and high intensity, with a short duration (approx. 0.8-1.5 h). Occupational physical activity was typically performed at light to moderate intensity with a very long duration (approx. 0.5-3 h). Moreover, leisure-time and occupational physical activity were almost negatively related. The few studies investigating effects on cardiovascular parameters revealed a rather unfavorable effect of occupational physical activity, while leisure-time physical activity was beneficial. The study quality was rated as fair and the risk of bias was moderate to high. The body of evidence was low.

CONCLUSIONS

This review confirmed that leisure-time and occupational physical activity of healthcare workers are opposed in their duration and intensity. Moreover, leisure-time and occupational physical activity seem to be negatively related and should be analyzed according to their relation to each other in specific occupations. Furthermore, results support the relationship between the paradox and cardiovascular parameters.

REGISTRATION

Preregistered on PROSPERO (CRD42021254572). Date of registration on PROSPERO: 19 May 2021.

TWEETABLE ABSTRACT

Does occupational physical activity adversely affect the cardiovascular health of healthcare workers in comparison to leisure-time physical activity?

Occupational Physical Activity and Coronary Heart Disease in Women's Health Initiative Observational Study

BACKGROUND

Women comprise nearly half of the labor force in our society, but the impact of the occupational psychical activity on women's heart health in later life was unclear. We conducted a case-cohort study to assess the association of occupational physical activity (OPA), alone and jointly with leisure-time physical activity (LTPA) and risk of coronary heart disease (CHD).

METHODS

We included women enrolled in Women's Health Initiative Observational Study who provided an occupational history at baseline and were followed until 2013 for the first occurrence of myocardial infarction or death from CHD (mean age ± SD = 63.4 ± 7.2). A total of 5,243 women free of CHD at baseline were randomly selected into a subcohort and 3,421 CHD events were adjudicated during follow-up. Through linkage of Standard Occupational Classification codes to the Occupational Information Network, we assessed cumulative and most recent exposure of OPA. LTPA was assessed through Women's Health Initiative's physical activity questionnaire. Weighted Cox proportional hazard models were used to evaluate CHD risk.

RESULTS

After adjustment for demographic and socioeconomic factors, levels of OPA were not associated with CHD risk. Compared with women with low OPA and high LTPA, women with moderate to high cumulative OPA and low LTPA had relative high CHD risk (hazard ratio [HR]: 1.54, 95% confidence interval [CI]: 1.26, 1.88 for moderate OPA and HR: 1.46. 95% CI: 1.20, 1.78 for high OPA).

DISCUSSION

Results from this study suggest no overall association between lifetime OPA and CHD risk in women, but the impact of OPA varies by LTPA levels.