Social jetlag, sleep‐related parameters, and glycemic control in adults with type 1 diabetes: Results of a cross‐sectional study

Abstract Background Social jetlag (SJL) is a small recurrent circadian rhythm disruption and the most frequent form of circadian rhythm misalignment. The main aim of this study was to investigate the effect of SJL on glycemic control, as assessed by HbA1c, in real‐life settings. Methods In all, 115 consecutive patients with type 1 diabetes (T1D) were analyzed cross‐sectionally. Data on bedtime, sleep onset latency, and wake up time on weekdays and weekends during the previous month were collected from all participants and used to calculate SJL, chronotype, and sleep duration. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). A PSQI score > 5 was considered as an indicator of poor sleep quality. Results Patients with SJL ≥ 1 hour had significantly higher adjusted values of HbA1c than those with SJL <1 hour (8.7% vs 8.0%; P = 0.029). In unadjusted multivariate regression analysis, SJL ≥ 1 hour and poor sleep quality were significant predictors of HbA1c values, explaining 22.7% and 23.5%, respectively, of the increase in HbA1c. After adjusting for age, sex, diabetes duration, insulin dose (kg/d), insulin regimen and body mass index, only SJL ≥ 1 hour remained associated with HbA1c (β = 0.253; P = 0.026). There was no significant interaction between SJL ≥ 1 hour and poor sleep quality in either the unadjusted or adjusted models ( P interaction = 0.914). Conclusions In patients with T1D, SJL is associated with poor glycemic control, acting independently of sleep quality, sleep duration, and chronotype to exert a deleterious effect on glycemic control.