Circadian Disruption of Melatonin among Night Shift Workers and Its Effect on Glycemic Variability

Abstract

Melatonin is a pineal gland secreted hormone controlling sleep wakefullness. Light is a stimulus and hence this hormone exhibits circadian rhythm. Melatonin has pleiotropic effects on carbohydrate and lipid metabolisms. Glycemic variability is defined as variations in interstitial glucose levels measured every 15 seconds using a sensor-based technique. It is the result of constant carbohydrate metabolism and insulin action. Melatonin also has rhythms that are more akin to a nocturnal hormone. It affects glycemic variability. Variability is associated with a very high cardiac risk factor. Melatonin rhythm may be disrupted in night shift workers as a result of light exposure during the night, with implications for insulin secretion and glycemic variability. Correlation provides greater insight into the rhythmic hormonal activity and altered glucose homeostasis that predispose to diabetes, and thus this study was done to establish the correlation. This study was done to evaluate the effect of melatonin levels on altering glycemic control among night shift workers. This case control study included 40night shift workers both male and female (cases) aged 25-35years and 40 healthy controls of same age group. Blood samples for melatonin estimation were collected at 9PM and 6AM (after night shift work) by venepuncture and serum separated. Serum melatonin levels were estimated by ELISA method. Fasting and post prandial blood glucose were estimated by GOD-POD method and glycemic variability analyzed by Abbott biosensors. Data was analyzed using SPSS package. Night shift workers were found to have decreased melatonin levels and altered blood glucose levels compared to the control group. Melatonin has a negative influence on glycemic variability. This fact was evidenced in our study. Hence this study will help us to understand and intervene.