title: Effects of Sleep Disorders on Hemoglobin A1c Levels in Type 2 Diabetic Patients.
abstract: BACKGROUND
  Studies have reported the presence of sleep disorders in approximately 50-70% of diabetic patients, and these may contribute to poor glycemic control, diabetic neuropathy, and overnight hypoglycemia. The aim of this study was to determine the frequency of sleep disorders in diabetic patients, and to investigate possible relationships between scores of these sleep disorders and obstructive sleep apnea syndrome (OSAS) and diabetic parameters (fasting blood glucose, glycated hemoglobin A1c [HbA1c], and lipid levels).
  
  
  METHODS
  We used the Berlin questionnaire (BQ) for OSAS, the Epworth Sleepiness Scale (ESS), and the Pittsburgh Sleep Quality Index (PSQI) to determine the frequency of sleep disorders and their possible relationships with fasting blood glucose, HbA1c, and lipid levels.
  
  
  RESULTS
  The study included 585 type 2 diabetic patients admitted to family medicine clinics between October and December 2014. Sleep, sleep quality, and sleep scores were used as the dependent variables in the analysis. The ESS scores showed that 54.40% of patients experienced excessive daytime sleepiness, and according to the PSQI, 64.30% experienced poor-quality sleep. The BQ results indicated that 50.20% of patients were at high-risk of OSAS. HbA1c levels correlated significantly with the ESS and PSQI results (r = 0.23, P < 0.001 and r = 0.14, P = 0.001, respectively), and were significantly higher in those with high-risk of OSAS as defined by the BQ (P < 0.001). These results showed that HbA1c levels were related to sleep disorders.
  
  
  CONCLUSIONS
  Sleep disorders are common in diabetic patients and negatively affect the control of diabetes. Conversely, poor diabetes control is an important factor disturbing sleep quality. Addressing sleep disturbances in patients who have difficulty controlling their blood glucose has dual benefits: Preventing diabetic complications caused by sleep disturbance and improving diabetes control.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Keskin
authors.forename: Murat
authors.initials: M
authors.lastname: Ünalacak
authors.affiliation: Department of Family Medicine, Faculty of Medicine, Eskişehir Osmangazi University, Eskişehir 9026100, Turkey.
authors.forename: Uğur
authors.initials: U
authors.lastname: Bilge
authors.forename: Pinar
authors.initials: P
authors.lastname: Yildiz
authors.forename: Seda
authors.initials: S
authors.lastname: Güler
authors.forename: Engin Burak
authors.initials: EB
authors.lastname: Selçuk
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Bilgin
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000378:metabolism*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000150:complications; D012893:Sleep Wake Disorders / Q000097:blood* / Q000150:complications*
chemical_list: D006442:Glycated Hemoglobin