Serum Level of Cortisol, hsCRP and IL-6 in Depressed Rotational Shift Workers

Background: Depression and sleep disorders are more prevalent among rotational shift workers than regular day workers. People with sleep disorders have higher inflammatory and pre-inflammatory cytokines than those in the control group. Objectives: The present study was conducted to investigate serum level of high sensitivity C-reactive protein (hsCRP), Interleukin-6 (IL-6) and cortisol among depressed rotational shift workers at Iran petroleum industry. Materials and Methods: In this cross sectional study, 136 shift workers were studied based on the inclusion and exclusion criteria. Demographic information was collected using a self-administered general questionnaire and depression score was gathered according to 21-question Beck depression inventory. Also, weight and height were measured to calculate body mass index and history of disease was collected based on their occupation profile at health center of Tehran Shahid Tondgoyan oil refinery. Results: Mean and standard deviation of serum concentration of hsCRP, IL-6 and cortisol were 1.03 ± 1.56, 1.24 ± 1.24 and 13.12 ± 3.93 respectively; while mean and standard deviation of depression score and BMI were 14.07 ± 3.84 and 24.92 ± 3.65, respectively. Depression score had a positive correlation with rotational shift work experience and work experience (r = 0.218 and r = 0.212, respectively, P < 0.05). An inverse relation was found between serum concentrations of cortisol and age, work experience and BMI (r = -0.236 and P < 0.05, r = -0.174 and P < 0.05, r = -0.288 and P < 0.05, respectively). IL-6 and hsCRP had a positive relation with each other (r = 0.616, P < 0.001). Serum concentration of hsCRP had a positive correlation with BMI (r = 0.241, P < 0.01). Conclusions: There was no significant correlation between depression score and inflammatory markers among depressed shift workers. However, depression score had a significant correlation with shift work experience.