Objective Sleep and Circadian Metrics in Adolescents With Type 1 Diabetes Mellitus: A Systematic Review

This review synthesizes evidence on objectively measured sleep and circadian parameters in adolescents with type 1 diabetes mellitus (T1DM) and associations with glycaemic outcomes.

A systematic review was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and registered with PROSPERO (CRD420251164605). Five electronic databases were searched for studies reporting objective sleep or circadian measures in adolescents aged 10 to 19 years with T1DM. Eligible designs included cross-sectional, cohort, longitudinal, and randomized controlled trials. Risk of bias was assessed using the JBI checklist, Newcastle-Ottawa Scale, and Cochrane RoB 2. Narrative synthesis was conducted per Synthesis Without Meta-analysis guidelines.

Ten studies met inclusion criteria. Adolescents with T1DM consistently demonstrated suboptimal sleep duration (mean total sleep time 6.8-7.6 h/night), high night-to-night variability, impaired continuity, and circadian misalignment. Associations between sleep duration and HbA1c were inconsistent; however, sleep efficiency, fragmentation, variability, and circadian timing showed more consistent associations with higher HbA1c and increased glucose variability. Only 1 study included a healthy control group; most were single-cohort observational designs, limiting causal inference. Risk of bias was moderate in cross-sectional and low to moderate in cohort studies. Randomized evidence comprised 2 trials; neither demonstrated sustained improvements in objective sleep outcomes or glycaemic control with closed-loop therapy versus standard care.

In adolescents with T1DM, disturbed sleep involves insufficient duration, fragmentation, variability, and circadian misalignment. Sleep efficiency and regularity showed more consistent associations with glycaemic outcomes than duration alone, positioning sleep assessment as a potential research target in adolescent diabetes care. Future research should integrate standardized actigraphy with continuous glucose monitoring to establish causal pathways.