STUDY OBJECTIVES: The role of circadian misalignment has been implicated in metabolic health, not excluding glycemic control, but its role in type 1 diabetes mellitus (T1DM) has not been fully understood. The aim of the study was to investigate the relationship between the degree of circadian misalignment and the efficacy of glycemic control in T1DM patients.
METHODS: This cross-sectional study included 879 patients within the general Czech population who have been diagnosed with T1DM for a period of at least 10 years (mean HbA1C 52.9 ± 0.4 mmol/mol). The patients were aged 18-86 years and comprised 45 % females. All participants filled out the Munich Chronotype Questionnaire (MCTQ) to assess their individual chronotype and calculate social jetlag (SJL). The individual chronotypes were also assessed using self-reporting best alertness time (BAmid). Sleep quality was self-assessed on a 4-point scale from 1 (best) to 4 (worst). T1DM management was evaluated through continuous glucose monitoring data (CGM) including the glycemia risk index (GRI). For the non-diabetic control group, we utilized data obtained from wave 5 of a nationally representative longitudinal Czech Household Panel Survey (CHPS), which involved 1757 subjects without diabetes aged 18-86 years. Data were analyzed through cross-sectional univariate and multivariate analyses.
RESULTS: T1DM patients had later average chronotype and significantly higher SJL compared to controls. Across all adjusted models, higher SJL was consistently associated with T1DM. Within the T1DM cohort, increased SJL was positively associated with higher GRI (r = 0.12, P = 0.0029), while chronotype itself showed no independent association with glycemic control. Overall, metabolic markers showed better outcomes in T1DM patients than in control non-diabetic population.
CONCLUSIONS: Social jetlag was robustly correlated with both T1DM and impaired glycemic management. These findings call for systematic examination of such characteristics in patients with T1DM and may open the door to taking circadian aspects into account when striving for optimal management of T1DM.