Association of Bedtime with Early-Onset Diabetes and Islet Beta Cell Function in Patients with Newly Diagnosed Type 2 Diabetes Mellitus

OBJECTIVE: To investigate the association of bedtime with the risk of early-onset diabetes mellitus (DM) and islet beta cell function. METHODS: 138 participants with treat-naïve DM were included in this study. All participants underwent a 75g oral glucose tolerance test. Sleep habit was obtained through a standardized questionnaire. Bedtime was categorized as < 22:00, 22:00–24:00, and ≥ 24:00 in this study. Multivariate logistic regression and multiple linear regression were used to estimate the association between bedtime and risk of early-onset DM and islet beta cell function, respectively. RESULTS: Patients with early-onset DM had a later bedtime than those with late-onset DM. Individuals with bedtime ≥ 24:00 had a higher prevalence of early-onset DM than those with bedtime at 22:00–24:00 and < 22:00 (51.2% vs 29.3% vs 14.3%, respectively, p = 0.028). The multivariate logistic regression showed that per hour later in bedtime was associated with a 52% increased risk of early-onset DM (p = 0.023). Patients with bedtime after 24:00 had a 146% increased risk of early-onset DM compared to those went to bed between 22:00 to 24:00 (OR = 2.46, 95% CI 1.05 to 5.77, p = 0.039). The multiple linear regression showed that bedtime was independently negatively correlated with late-phase insulin secretion (assessed by disposition index, DI(120)). CONCLUSION: Later bedtime was associated with worse late-phase insulin secretion and may be a risk factor for early-onset DM. Proper bedtime to lower risk of early-onset DM deserves further investigation.