Sleep pattern is associated with adipokine levels and nutritional markers in resident physicians

Abstract

Shift work and long hours of work are common in medical training and have been associated with a higher propensity for developing nutritional problems and obesity. Changes in leptin and ghrelin concentrations – two hormones that contribute importantly to the central regulation of food intake – are poorly described in this population. The aim of this study was to identify possible negative associations between sleep patterns, nutritional status and serum levels of adipokines. The study included 72 resident physicians (52 women and 20 men) who underwent the following assessments: nutritional assessment (3-day dietary recall evaluated by the Adapted Healthy Eating Index), anthropometric variables, fasting metabolism, physical activity level, sleep quality and sleepiness. Resident physicians with poor sleep quality reported greater weight gain after the beginning of residency (5.1 and 3.0 kg, respectively; p = 0.01) and higher frequency of abnormal waist circumference (44.2 and 17.6%, respectively; p = 0.04) than those with better sleep quality. Mean ghrelin concentration was greater in volunteers with poor sleep quality (64.6 ± 67.8 and 26.2 ± 25.0 pg/mL, respectively; p = 0.04). Women identified as having excessive daytime sleepiness had lower levels of leptin (9.57 ± 10.4 ng/mL versus 16.49 ± 11.4 ng/mL, respectively; p = 0.03) than those without excessive sleepiness. Furthermore, correlations were found between hours of additional work per week and: intake of cereals, bread and pasta (r = 0.22, p = 0.01); intake of servings of fruits (r = −0.20; p = 0.02) and beans (r = −0.21; p = 0.01); and global score for Adapted Healthy Eating Index (r = −0.23; p = 0.008; Table 3). The sleep quality total score correlated with servings of beans (r = −0.22; p = 0.01) and servings of oils (r = 0.23; p = 0.008). Significant correlations were found between mean of time of sleep and servings of cereals, bread and pasta (r = 0.20; p = 0.02), servings of meat (r = −0.29; p = 0.02) and cholesterol levels (r = 0.27; p = 0.03). These observations indicate that sleep patterns and long working hours of resident physicians are negatively associated with biological markers related to central food control, the lipid profile, cholesterol levels and eating healthy foods. These factors may predispose these shift workers to become overweight and develop metabolic disorders.

• Ghrelin
• leptin
• nutrition
• residency training
• sleep

Acknowledgements

We thank all of the volunteers involved and the Clinical Hospital of Federal University of Uberlândia. We also want to give special thanks to Magda Bignoto and Maria Cristina de Martino.