Shift Work, Long Work Hours, Inflammatory Markers, and Chronic Kidney Disease in HCHS/SOL and NHANES

Shift work is associated with chronic disease via disruption of the body’s natural circadian rhythms. Many functions of the body fluctuate in a circadian manner, including the immune and renal systems. We examined the impact of shift work and long work hours on inflammation and chronic kidney disease (CKD) in two different Hispanic/Latino study populations using data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) and the National Health and Nutrition Examination Survey (NHANES). Cross-sectional associations between shift work and work hours with high-sensitivity C-reactive protein (hs-CRP), white blood cell (WBC) count, estimated glomerular filtration rate (eGFR), and urine albumin-creatine ratio (UACR) were analyzed using multivariable linear regression. Additionally, associations between shift work and work hours with the odds of CKD were investigated with multivariable logistic regression. We found that night shift workers who also worked long work hours (≥40 hours per week) had large significant increases in WBC counts in the HCHS/SOL study population. In addition, we found increased odds of CKD for male and female night shift workers compared to day shift workers in both the HCHS/SOL and NHANES study populations. The results persisted after controlling for multiple confounding factors and variables potentially on the causal pathway between occupational characteristics and markers of inflammation and kidney disease. Our findings indicated that night shift work, over other shift schedule types, had the greatest association with inflammation and CKD, which is consistent with prior research on shift work and disease. However, this is the first ever study to examine these associations in Hispanics/Latinos, so further research is needed. Hispanics/Latinos are overrepresented in alternate work schedules in the US, so this research could help shape policies to protect Hispanic/Latino workers.