Correlation between serum 25(OH) vitamin D level and sleep quality in elderly patients with type 2 diabetes

Background: Untreated sleep disorders have been linked with type 2 diabetes in previous evidence. This study was to investigate the correlation between serum 25(OH) vitamin D level and sleep quality in elderly patients with type 2 diabetes and reveal the therapeutic potential of 25(OH) vitamin D-based treatments to improve sleeping quality and its effect on diabetes management. Methods: The sleep quality of 186 elderly patients with type 2 diabetes were assessed by questionaires of Pittsburgh sleep index (PSQI), with a cutoff point of PSQI ≥ 7 defined as poor sleep. The measurement of serum 25(OH) vitamin D , fasting blood glucose, glycosylated hemoglobin, serum creatinine, total cholesterol, triglyceride, low-density lipoprotein cholesterol, and urinary albumin/creatinine ratio were collected. History of diabetic nephropathy, diabetic retinopathy, peripheral neuropathy, blood pressure, height, weight, hypoglycemic drug use, and the duration of diabetes also were recorded. Both univariate and multivariate logistic regression analysis was used to investigate the relationship of serum 25(OH) vitamin D and sleep quality in elderly patients with type 2 diabetes. Results: The age of elderly patients with type 2 diabetes was 73.6(4.3) years., and duration of diabetes was 8.8(3.0) years. In the study, inadequate quality of sleep was reported in 63% elderly patients with type 2 diabetes. This study revealed that lower level of 25(OH) vitamin D was significantly associated with poor sleep quality in type 2 diabetes patients(P < 0.05). Multivariate logistic regression analysis showed that 25(OH) vitamin D deficiency and the use of insulin were risk factors for of inadequate sleep quality in elderly patients with type 2 diabetes. Conclusions: Elderly type 2 diabetic patients with 25(OH) vitamin D deficiency showed a high incidence of poor sleep quality, low-level of 25(OH) vitamin D was a risk factor for inadequate quality of sleep in elderly patients with type 2 diabetes.