Dados do Trabalho

Título

Effect of the interaction between rotating shifts and BMI on sleep duration: an observational and prospective study

Introdução

Studies have highlighted that there is an association between irregular eating and sleeping patterns and obesity among shift-workers, caused by the shiftwork schedules.

Objetivo

To evaluate the effect of the interaction of rotating shift schedule and body mass index (BMI) on sleep duration among shift workers.

Métodos

The study included 30 males shift workers. The rotation shift schedule was carried out as follow: two days during the day (8:00 a.m. – 4:00p.m.); two days during the afternoon (4:00p.m. – 0:00a.m.); 24h free-day (0:00a.m. – 0:00a.m.); two days during the night (0:00a.m. – 8:00a.m.) and three days free. Sleep duration and the fragmentation of rest- activity rhythm (Intradaily Variability; IV) were evaluated by actigraphy. The effect of the interaction between shift and BMI on sleep duration was evaluated using Generalized Estimating Equations (GEE). The correlation between BMI and IV was accessed using Spearman’s rho test.

Resultados

The interaction between shift schedule and BMI had effect on sleep duration. Eutrophic subjects did not show differences on sleep duration throughout the shifts, while overweight and obese ones had a smaller sleep duration in the 24h free-day (overweight: 4.6h and obese: 4.5h) and in night shift (overweight: 5.8h and obese: 6.2h) than morning shift (overweight: 7.2h and obese: 8.2h) and free days (overweight: 7.1h and obese: 7.9h) (p<0.05). The BMI had positive correlation with IV (p<0.001).

Conclusões

Excessive BMI influences the sleep duration throughout the rotating shift schedule, while the eutrophic subjects maintain a routine of sleep duration.

Palavras-chave

Shift workers; Rotation shift schedule; Sleep duration, BMI.