Receptor solúvel de leptina e índice de leptina livre em trabalhadores em turnos

Abstract

Concentrations of leptin - a hormone that contributes importantly to the central regulation of food intake - seem to be influenced by the shift work schedule. Soluble leptin receptors (OB-Re) are the major leptin-binding protein in blood and can affect leptin transport in the brain. As the daily concentrations of OB-Re have not been described in shift workers, we hypothesized that OB-Re concentrations and the free leptin index (FLI) do not vary throughout the day in shift workers as they do in day workers. To evaluate the daily profiles of OB-Re and FLI in shift and day workers, two shift-working groups (early morning and night shifts) and one group of day-shift workers were studied. They completed sleep, nutritional and metabolic assessments. Venous blood samples were collected every 4 hours over 24 hours to measure leptin and OB-Re levels. FLI was calculated by the ratio of free leptin to OB-Re levels. The Mixed-model ANOVAs indicated that OB-Re showed a significant main effect of shift, with the day workers showing higher OB-Re levels than the early morning (p=0,001) and night (p=0,004) groups. No effect of time or interaction between time x shift was observed in OB-Re. No main effect of shift, time or interaction between shift x time was observed for FLI (p>0.05). No significant differences were observed in mean 24-hours concentrations of Ob-Re and FLI between shift and day workers (p>0.05). We conclude that the concentration of OB-Re is altered by working on atypical schedules (early morning and night shifts) compared to day shifts.