Effects of sleep quality on glycemic control in patients with type 2 diabetes

Abstract

Objective To investigate the effect of sleep quality on glycemic control and relevant factors involved in subjects with type 2 diabetic mellitus(T2DM). Methods A total of 200 inpatients with T2DM were enrolled in this study. Each patient completed Pittsburg Sleep Quality Index (PSQI) questionnaire. The glycemic control target was <7%. All patients were evaluated by Zung Self-rating Depression Scale (SDS) for the mental status, the score of SDS ≥50 was defined as a depressive state. Patients were divided into two groups: non-sleep disorder group (n=88) and sleep disorder group (n=112) according to PSQI score ≥7 which was defined as the sleep disorder. The clinical characteristics of two groups were compared and analyzed. Results The incidence of sleep disorder was 56% in the overall population. In the sleep disorders group, Age, hemoglobin A, glycosylated (HbA1c), fasting plasma glucose, 0.5-hour as well as 2-hour postprandial plasma glucose, fasting serum total cholesterol, triglycerides, the score of SDS and the incidence of depression were significantly greater (t=-19.49--1.99, χ2=9.931, all P<0.05), whereas fasting C-peptide, 0.5-hour postprandial C-peptide and body mass index (BMI) were significantly lower (t=2.07, 2.14, 2.35, all P<0.05) than those of the non-sleep disorder group. Glycemic control target rate of PSQI<5 group, PSQI≥5 to 7 group, PSQI ≥7 to 9 group and PSQI≥9 group was 27.9%, 19.6%, 10.0% and 8.6%, respectively. Patients with a higher score of PSQI were less likely to reach glycemic targets (P< 0.05). Multiple logistic regression analysis indicated that sleep disorders was positively correlated with increased age, male, HbA1c and depression, however, sleep disorders was negatively related to BMI (OR=1.04, 2.38, 2.98, 2.14, 0.89, respectively, all P<0.05). There was a positive association between sleep disorders, 2-hour postprandial plasma glucose and HbA1c≥7%, however, HbA1c≥7% was inversely associated with insulin therapy (OR=2.81, 1.21, 0.33, all P<0.05). Conclusion Sleep disorders are prevalent in patients with T2DM. Hyperglycemia and sleep disorders interact with each other. Sleep disorders probably cause psychological health problems. Management of sleep quality and glucose control in patients with T2DM should be an effective approach for sleep and higher glycemic control target rate. Key words: Diabetic mellitus, type 2; Sleep quality; Hemoglobin A, glycosylated