Self-reported nocturnal sleep duration and glycosylated hemoglobin A in the Study of Cardiovascular Risks in Adolescents (ERICA).

ABSTRACT

OBJECTIVE: At present, epidemiologic studies regarding the relationship between sleep duration and glucose metabolism in adolescents are scarce. The objective was to investigate the association between self-reported nocturnal sleep duration and glycosylated hemoglobin A in 12- to 17-year-old Brazilian adolescents. PATIENTS/METHODS: A school-based multicenter cross-sectional study was carried out in private and public schools from 273 municipalities with more than 100,000 inhabitants. The final sample comprised 24,923 adolescents. A self-administered questionnaire was used. Blood tests included glucose, insulin, glycosylated hemoglobin A and serum lipids. Age, sex, skin color, school type, body mass index (BMI), physical activity, and Brazilian regions were studied as possible effect modifiers and/or confounders using linear regression. RESULTS: A significant positive association was found between more than 12 h of nocturnal sleep and glycosylated hemoglobin A in two Brazilian regions Southeast and South, even after adjustment for age, sex, skin color, and BMI (coefficients of 0.142 and 0.339, respectively). No association was found with nocturnal sleep duration <7 h. CONCLUSION: Notably, a significant positive relationship was found between more than 12 h of nocturnal sleep duration and glycosylated hemoglobin A in two Brazilian regions. The specific pubertal sleep curtailment can be a compensatory mechanism for dealing with the insulin resistance during adolescence. Those that escape from this regulatory strategy and sleep longer than the adequate duration, break down this balance and tend to damage their glucose metabolism. To our knowledge, this is the first large scale study, of the association between sleep duration and glucose metabolism in adolescents.