Evaluation of metabolic and haematological impacts of light-at-night exposure on adult male Wistar rats under sleep restriction condition.

Abstract

Health implications of shift work could not be completely due to exposure to light-at-night (LAN). This study evaluated metabolic and haematological impacts of LAN exposure on adult male Wistar rats under sleep restriction condition. The animals were grouped into control (n=8) and LAN exposed (n=8) groups. The controls were sleep restricted (SR) by gentle handling. In addition to SR, the LAN exposed group were exposed to LAN during the first five hours of scotophase for six weeks. Body weight, fasting blood glucose, lipid profile, full blood counts, CD4+ cells, malondialdehyde, superoxide dismutase and catalase were all assessed using their respective protocols. Statistical Package for Social Sciences (SPSS Version 20) was used to analyze and Mean±SEM was used to analyze and summarize the data. Intergroup differences were investigated using Student’s t-test and p≤ 0.05 was considered statistically significant. The results have shown that LAN-exposed rats eat less and have gained more body weight than controls. LAN-exposed rats also had higher fasting blood glucose. On the contrary, there is no statistical difference between the two groups for markers of oxidative stress, triglyceride-glucose index, high-density lipoprotein, and atherogenic index of plasma. In conclusion, the present study has shown that LAN exposure could cause metabolic and hematological impairments in sleep-restricted, Wistar rats. Hence, it might predispose exposed subjects to obesity, diabetes mellitus and adverse cardiovascular events.