Oxidative stress and insulin resistance in policemen working shifts.

PURPOSE: Shift work is a work schedule involving irregular or unusual hours, compared to those of a normal daytime work schedule. In developed countries, night shift work is very common. In several cities of our country, 12/24 shift system is implemented in police organization. While night shift work composes half of the 20 shift in a month, in ergonomic shift system, an alternative shift schedule, shift work can be performed in three shifts in a day. In this study, we aimed to investigate the effects of 12/24 shift work system on insulin resistance and oxidative stress and systemic inflammation. METHODS: Two hundred and four 12/24 shift workers (age 44.3 ± 5.6 years) and 193 ergonomic shift workers (age 42.6 ± 5.5 years) were included to study. Serum oxidized LDL (ox-LDL), neutrophil gelatinase lipocalin-2 (NGAL) as oxidative stress markers, glucose, insulin, ferritin, high-sensitive C-reactive protein (hsCRP) and erythrocyte sedimentation rate values were measured. Homeostasis model assessment for insulin resistance (HOMA-IR) was calculated to evaluate insulin resistance. RESULTS: Serum ox-LDL, HOMA-IR, hsCRP and NGAL levels in 12/24 shift system were found to be significantly higher compared with ergonomic shift workers (p < 0.0001, p = 0.02, p = 0.03, p = 0.02, respectively). When evaluated all subjects, weak but significant correlation was found between HOMA-IR with ox-LDL (r = 0.12, p = 0.01), hsCRP (r = 0.17, p = 0.001) and ferritin (r = 0.15, r = 0.003). Also in 12/24 shift work group, there were significant correlations between HOMA-IR with hsCRP (r = 0.17, p = 0.01) and ferritin (r = 0.25, p = 0.0001). CONCLUSION: It may be concluded that 12/24 shift system might give rise to insulin resistance and oxidative stress. Additionally, workers in this system may under risk of systemic inflammatory response. Working hours must be arranged in accordance with the physiological rhythm.

The Impact of Shift Type on Oxidative Stress, Inflammation, and Platelet Activation.

OBJECTIVE: Rotating shift is known to disrupt circadian rhythms. The 12/24 shift system, with frequent day-night rotations and the ergonomic shift system (ESS), with 90% less rotations were compared for their impacts on oxidative stress, inflammation, and platelet activation by using pentraxin 3 (PTX3), urinary 15-isoprostane F2t, and 11-dehydrotromboxane B2 (11-DTB2). METHODS: All tests were performed by enzyme linked immunosorbent assay (ELISA). Unpaired t test and Pearson correlation analysis were employed. RESULTS: Two hundred twenty 12/24 and 198 ESS workers were included. Plasma PTX3 and urinary 15-isoprostane F2t levels were not different between groups. Urinary 11-DTB2 in 12/24 workers were found significantly higher compared with ESS workers (P < 0.0001). A weak but significant correlation was found between urinary 15-isoprostane F2t and urinary 11-DTB2 levels (r = 0.17, P = 0.001). CONCLUSIONS: 12/24 rotating shift was found to cause platelet activation disturbances.