Adults with type 1 diabetes who sleep 7-9 hours per night present lower glycemic variability compared with those sleeping less or more.
Key Findings
Results
Half of adults with type 1 diabetes in this study did not meet the National Sleep Foundation's recommended sleep duration of 7-9 hours per night.
155 participants with type 1 diabetes completed the Pittsburgh Sleep Quality Index (PSQI) questionnaire
78 participants (50.3%) met the NSF criteria of recommended sleep duration (7-9 hours)
56 participants (36.1%) declared sleeping less than 7 hours per night
21 participants (13.6%) declared sleeping more than 9 hours per night
Mean age was 33 (SD 9) years; median diabetes duration was 12 (IQR 8-20) years
Results
Participants sleeping outside the recommended 7-9 hour range had significantly higher mean glucose levels compared to those sleeping 7-9 hours per night.
Both the short sleep (<7h) and long sleep (>9h) groups showed significantly higher mean glucose than the recommended sleep duration group
Comparisons were made using ANOVA/Kruskal-Wallis test with post-hoc Bonferroni correction
No differences in HbA1c were found among the three sleep duration groups
The association was observed despite no significant differences in diabetes duration across groups
Results
Both short and long sleepers with type 1 diabetes had significantly higher glycemic variability across multiple metrics compared to those sleeping 7-9 hours.
Compared with participants sleeping 7-9h per night, each other group had significantly higher coefficient of glycemic variability (CV), glycemia risk index (GRI), high blood glucose index (HBGI), mean amplitude of glucose excursions (MAGE), glycemic risk assessment in diabetes equation (GRADE), and mean of daily differences (MODD)
Time-in-range (TIR) was significantly lower in both the short and long sleep groups compared to the 7-9 hour group
CGM data were analyzed using Glyculator 3.0
No differences in low blood glucose index (LBGI) were found among the groups
Results
Sleeping 7-9 hours per night was independently associated with lower glycemic variability after adjustment for potential confounders.
In multivariable logistic regression analysis, sleeping 7-9 hours per night was associated with lower CV, MAGE, and MODD
Models were adjusted for age, sex, and HbA1c
The association between recommended sleep duration and reduced glycemic variability persisted even after controlling for HbA1c, suggesting an effect independent of average glucose control
Results
Sleep quality, as measured by the Pittsburgh Sleep Quality Index, did not differ significantly among the three sleep duration groups.
All 155 participants completed the Pittsburgh Sleep Quality Index (PSQI) questionnaire
No statistically significant differences in PSQI-measured sleep quality were found among the short, recommended, and long sleep duration groups
This suggests sleep duration, rather than sleep quality, was the primary factor associated with glycemic variability differences in this sample
What This Means
This research suggests that the amount of sleep adults with type 1 diabetes get each night is closely tied to how stable their blood sugar levels are throughout the day. In a study of 155 adults with type 1 diabetes, those who slept the recommended 7-9 hours per night had significantly better blood sugar control — including more time spent in the healthy glucose range and less fluctuation in their glucose levels — compared to both those who slept too little (under 7 hours) and those who slept too much (over 9 hours). Notably, about half the participants were not meeting the recommended sleep duration, with 36% sleeping less than 7 hours and 14% sleeping more than 9 hours.
Importantly, this link between recommended sleep duration and better glucose stability held up even after accounting for age, sex, and average blood sugar levels (HbA1c), suggesting that sleep duration may have an effect on day-to-day glucose fluctuations that goes beyond overall diabetes control. Interestingly, the overall quality of sleep — not just the amount — did not differ significantly between groups, pointing to sleep duration as the key variable in this study.
This research suggests that supporting people with type 1 diabetes in achieving adequate nightly sleep (7-9 hours) could be an important, often overlooked factor in helping them manage their condition. Because the study is cross-sectional (a snapshot in time), it cannot prove that sleep duration directly causes changes in blood sugar variability, but the findings highlight sleep as a potentially modifiable lifestyle factor worth considering in diabetes care.
Duda-Sobczak A, Kulecki M, Pilacinski S, Naskret D, Zozulinska-Ziolkiewicz D. (2026). Adults with type 1 diabetes who sleep 7-9 hours per night present lower glycemic variability: a cross-sectional study.. Frontiers in endocrinology. https://doi.org/10.3389/fendo.2025.1745272