Glycaemic variability remains a major challenge for adults with type 1 diabetes (T1D), affecting treatment outcomes. EASD 2025 highlighted the link between sleep duration and glucose stability in T1D patients. In a study of 155 adults with T1D (33±9 years, 47% male, median diabetes duration 12 years), sleep duration and quality were assessed via the Pittsburgh Sleep Quality Index, while continuous glucose monitoring captured detailed glycaemic metrics. Participants sleeping 7–9 hours daily were compared with those sleeping less than 7 or more than 9 hours.

Compared to the recommended sleep group, short or long sleepers exhibited higher mean glucose (172–175 vs 161 mg/dL), greater coefficient of variation (38.6–38.8 vs 35.6%), higher mean amplitude of glucose excursions (127–127.8 vs 108 mg/dL), and increased mean of daily differences (68–69.3 vs 57.6 mg/dL). Time-in-range was lower in non-recommended sleepers (56–57.7% vs 63.5%). Multivariable analysis adjusting for age, sex, and HbA1c confirmed that 7–9 hours of sleep was independently associated with lower glycaemic variability. Sleep quality and HbA1c did not differ between groups.

These findings suggest that adhering to NSF-recommended sleep duration may improve glycaemic stability in adults with T1D and should be considered in routine diabetes care.