Work stress may disrupt metabolism, immune response
Work stress appears to alter the metabolic profile and promote systemic inflammation, reveals a recent large-scale study on a French population. Moreover, work stress is also associated with poor liver function in males, suggesting elevated levels of alcohol consumption.
“Findings from over 43,000 men and women suggest that work stress is associated with altered metabolic profile, in particular adverse adiposity and blood lipid parameters, as well as with increased systemic inflammation as indicated by elevated white cell count,” researchers reported.
On the other hand, “[n]o robust associations were observed with lung function, haemoglobin, glucose levels or blood pressure measures, including pulse pressure,” they added.
In the study population of 43,594 French adults (52 percent female), 48.6 percent reported experiencing work stress, defined as “an imbalance between perceived high efforts and low rewards at work” according to the Effort-Reward Imbalance model. Analysed by sex, 46.1 percent of males and 51.0 percent of females reported work stress. [Sci Rep 2017;7:9282]
In regression analysis, and in both males and females, work stress was significantly associated with higher body mass index (BMI; β, 0.07 and β, 0.09 respectively; p<0.001) and waist circumference (β, 0.08 and β, 0.06, respectively; p<0.001).
Higher waist-to-hip ratio was significantly correlated with work stress in males only (β, 0.06; p<0.001). All above associations remained significant even after adjusting for age, economic status, depressive symptoms, chronic diseases and health-related behaviours.
In males, those under work stress had significantly higher levels of triglycerides (β, 0.08; p<0.001), total cholesterol (β, 0.04; p=0.006) and low-density lipoprotein cholesterol (LDL-C; β, 0.04; p=0.006) than in males not under work stress. Levels of high-density lipoprotein cholesterol were significantly lower (HDL-C; β, -0.06; p<0.001). These remained significant even after adjusting for confounders.
Moreover, significantly higher levels of gamma-glutamyltransferase (gamma-GT; β, 0.03; p=0.023), alanine transaminase (ALT; β, 0.06; p=0.001) and platelets (β, 0.04; p=0.005) after adjustments were observed in males only.
Previous studies have shown that work stress, defined as either long working hours or imbalances in the effort-reward system, lead to risky alcohol drinking behaviours and dependence among men. Such an unhealthy coping mechanism may serve as an “indirect behavioural pathway between work stress and cardiovascular diseases,” according to researchers. [BMJ 2015;350:g7772; J Occup Env Med 2004;61:219-224]
“Our observation on the association of work stress with adverse liver function indicators in men is novel. This is likely to reflect increased alcohol consumption among stressed men,” said researchers.
In females, only levels of HDL-C were significantly different between those who were and were not under work stress after adjustments (β, -0.06; p≤0.001).
“Our findings show that work stress in terms of effort-reward imbalance is linked to altered biomarker levels across multiple systems that affect the risk of diabetes and cardiovascular disease,” said researchers.
“After taking into account all the main and sensitivity analyses, the most robust associations with work stress among men were those of BMI, waist circumference, waist-hip ratio, HDL and white blood cell count. Among women, the most robust associations were observed with BMI and white blood cell count,” they added.