Shift Work and the Relationship with Metabolic Syndrome in Chinese Aged Workers

Abstract

BackgroundShift work is indicated to be associated with adverse metabolic disorders. However, potential effects of shift work on metabolic syndrome (MetS) and its components have not been well established.MethodsIn total, 26,382 workers from Dongfeng-Tongji Cohort were included in this study. Information on shift work history was gathered through questionnaires and metabolic traits were measured. Logistic regression models were used to calculate the odds ratio (OR) and 95% confidence interval (CI) for long-term shift work related with MetS and each component, respectively. Further stratification analysis was performed to detect the differences on MetS between female and male shift workers.ResultsLong-term shift work was associated with MetS without adjusting for any confounders. Compared with the group of non-shift work, the multivariate-adjusted ORs (95%CI) of MetS associated with 1–10, 11−20, and ≥20y of shift work were 1.05 (0.95−1.16), 1.14 (1.03−1.26), 1.16 (1.01−1.31), respectively. In female workers, we found a dose-response relationship that every 10 years increase in shift work was associated with a 10% (95% CI: 1%−20%) elevated OR of MetS, while no significant dose-response trend was found among male workers. Furthermore, shift work duration was significantly associated with ORs of high blood pressure (1.07, 1.01−1.13), long waist circumference (1.10, 1.01−1.20) and high glucose levels (1.09, 1.04−1.15). No significant association was observed between shift work and low HDL cholesterol) and raised triglyceride levels.ConclusionsLong-term shift work was associated with metabolic syndrome and the association might differ by gender in retired workers. Applicable intervention strategies are needed for prevention of metabolic disorders for shift workers.

Sleep duration as a mediator between an alternating day and night shift work schedule and metabolic syndrome among female hospital employees

“…This finding is in contrast to results from a meta-analysis that reported 10 or more years of shift work increased the risk of metabolic syndrome by 77% 2. Furthermore, a dose–response relationship between increasing years of shift work history and metabolic syndrome was found among women in a recent large study of Chinese workers, where every 10 years of shift work increased the OR for metabolic syndrome by 10% 29. It is possible that our study was underpowered, did not include enough variability in cumulative shift work exposure to detect a difference, or our comparator group included employees with other unmeasured personal or work characteristics that contributed to cardiometabolic risk.…”

Adverse metabolic and mental health outcomes associated with shiftwork in a population-based study of 277,168 workers in UK biobank

“…Interestingly however, previous studies consistently report little or no difference between the dietary intake of shiftworkers and non-shiftworkers [1,9,25,26] although the frequency and timing of meals is very potently disturbed, [26] and the risk of shiftworkers having metabolic syndrome was associated with the timing of meals but not with overall energy intake. [25] Human circadian rhythms in glucose and insulin sensitivity are optimised towards ingestion of food in daytime, yet shiftwork often necessitates that food is ingested at night when these endogenous metabolic rhythms are not prepared for food.…”

“…Keywords circadian depression diabetes neuroticism nightshift obesity shiftwork well being BACKGROUND Shiftwork is associated with detrimental effects on health and wellbeing, including increased risk of diabetes [1][2][3][4][5] and sleep problems, [6][7][8] higher body mass index (BMI) [1,[9][10][11][12], and increased signs of anxiety and depression. [8,13,14] Shiftworkers were once predominantly male, manufacturing sector workers, but this is no longer the case; a recent government survey reported that security services, transport and communications industries were the most common occupation of shiftworkers in the United Kingdom.…”

Morning Diastolic Blood Pressure May Be Independently Associated With Severity of Obstructive Sleep Apnea in Non-Hypertensive Patients: A Cross-Sectional Study

“…Due to its retrospective design, the study does not include potentially confounding variables such as shift work, which is considered a risk factor for hypertension, insulin resistance, obesity, and dyslipidaemia. [35][36][37] It has been suggested that shift work may cause a rise in BP or cause progression of hypertension [38][39][40][41][42] ; however, this is not supported by more recent studies. [43][44][45] Nevertheless, not including shift work as a confounding factor may be considered as a limitation and we recognize the need for controlling for shift work in future research on the subject.…”