Disturbed sleep in type 2 diabetes mellitus independent of chronic complications, pain, and nocturia

Abstract

This study was to compare the sleep quality in people with type 2 diabetes with healthy controls and to investigate the association of diabetes and sleep quality in people with type 2 diabetes without chronic complications. We also explored the effect of pain, nocturia, and obstructive sleep apnea (OSA) on sleep quality. Four hundred and five people were recruited in this case-control study. Sleep quality was assessed in 202 people with type 2 diabetes and was compared with 203 healthy individuals. All diabetic people were free from chronic complications. The Persian version of Pittsburgh Sleep Quality Index (PSQI) was used for the assessment of sleep quality. Poor sleep quality was defined as PSQI score >5. Poor sleep quality was more prevalent in people with type 2 diabetes. The odds ratio for poor sleep quality was 2.63 in people with long-standing diabetes (diabetes duration ≥10 years). Although the PSQI score was slightly better in diabetic people without pain/nocturia (P = 0.03), the prevalence of disturbed sleep showed no significant change after excluding these people from analysis. Diabetes was associated with 1.77-fold increase in risk of OSA, and poor sleep quality was more frequent in diabetic people at high risk for OSA (P = 0.005) independent of body weight. Long-standing diabetes was a significant predictor of poor sleep quality. Furthermore, the effect of diabetes on sleep quality was independent of its complications and other intervening risk factors such as pain/nocturia. Diabetes was also associated with OSA, stronger than the observed association between obesity and OSA.