Introduction: Sleep disorders and insufficient vitamin D levels can impair control of diabetes mellitus. The aim of this study was to determine the prevalence of sleep disorders by using Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI) and by comparing them with a control group, and to investigate the possible relationship among sleep disorders, scores, 25-OH Vitamin D levels (25VD) and HbA1C levels.

Materials and method: This study was conducted in type 2 diabetic patients who attended to the family medicine outpatient clinic for routine controls. One hundred and six geriatric patients having type 2 diabetes were included in the study, and simultaneously selected 102 adult age group patients were taken as controls. Blood analyses for routine diabetes control parameters (HbA1c, fasting blood glucose, lipid profile) were performed. Target value for HbA1C was accepted as below %7. Demographic form, the Pittsburgh Sleep Quality Index, and Epworth Sleepiness Scale were used as the data collection instruments.

Results: There are significant differences in PSQI and ESS scores between adult and geriatric diabetic patients (6.16 +/- 3.62 vs 6.96 +/- 3.42, p=0.070 and 7.84 +/- 5.37, p <0.001, respectively). 25VD levels were found as 22.40 +/- 13.85 ng/ml in the adult group, 18.65 +/- 14.17 ng/ml in the geriatric group. There is a significant difference between the groups in terms of vitamin D levels (p=0.007). Epworth categories were found to have an effect on HbA1c levels in geriatric patients. Changes in levels of ESS scores were found to be related with 4.784 fold increase in HbA1c levels. Vitamin D levels and ESS scores have major effects on HbA1C levels in elderly population (p=0.007, 0.001, respectively).

Conclusion: In elderly patients, low 25VD levels and daytime sleepiness are associated with abnormal HbA1c levels. These results are important indicators of roles of sleep quality and VD deficiency in glycemic control for elderly patients. In elderly diabetic patients, with difficult blood glucose regulation, sleep problems and VD deficiency must be considered.