Association of poor sleep quality with adverse glycaemic outcomes in Chinese Itadults with type 2 diabetes: a family-based cohort study
Bo Wu, Yilu Huang, Donghui Yang, Zizhu Li, Liangyou Wang, Chaowei FuObjectives
To examine the association between baseline sleep quality and subsequent glycaemic outcomes in adults with type 2 diabetes mellitus (T2DM), using repeated fasting blood glucose measurements and longitudinal glycaemic pattern analyses.
Design
Prospective cohort study.
Setting
The Taizhou Diabetes Family-based Cohort in Zhejiang Province, China.
Participants
A total of 1421 adults with T2DM with baseline sleep quality assessment and follow-up fasting blood glucose measurements were included.
Main outcome measures
Baseline sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Follow-up fasting blood glucose measurements were obtained through 30 June 2025. The primary outcomes were continuous fasting blood glucose levels and binary fasting blood glucose status defined as ≥7.0 mmol/L during follow-up. Secondary outcomes included glycaemic variability and latent glycaemic trajectory classes.
Results
Poorer baseline sleep quality was associated with less favourable glycaemic outcomes during follow-up. In the fully adjusted model, each 1-point increase in PSQI score was associated with a 0.096 mmol/L higher fasting blood glucose level (95% CI 0.081 to 0.111), and poor sleep quality was associated with a 0.669 mmol/L higher fasting blood glucose level (95% CI 0.547 to 0.791). For the binary outcome, each 1-point increase in PSQI score was associated with higher odds of fasting blood glucose ≥7.0 mmol/L (OR 1.10, 95% CI 1.08 to 1.12), and poor sleep quality was associated with 1.61-fold higher odds of fasting blood glucose ≥7.0 mmol/L (95% CI 1.37 to 1.91). Higher PSQI scores were also associated with greater glycaemic variability and higher odds of membership in less favourable glycaemic trajectory groups.
Conclusions
Among adults with T2DM, poorer baseline sleep quality was associated with higher fasting blood glucose levels, poorer glycaemic control, greater glycaemic variability and less favourable long-term glycaemic trajectories. These findings suggest that sleep quality may be a relevant and easily assessable marker for identifying individuals at risk of suboptimal long-term glycaemic management.