title: Intermittent hypoxia is an independent marker of poorer glycaemic control in patients with uncontrolled type 2 diabetes.
abstract: OBJECTIVE
  This study investigated the association between intermittent hypoxia and glycaemic control in patients with uncontrolled type 2 diabetes (T2D) not treated for sleep apnoea.
  
  
  METHODS
  This was a single-centre cross-sectional study of stable patients with T2D and HbA1c ≥7% (53 mmol/mol). Patients underwent overnight pulse oximetry and, if intermittent hypoxia-defined by a 4% oxyhaemoglobin desaturation index ≥15-was observed, respiratory polygraphy was performed. All participants completed the Pittsburgh Sleep Questionnaire and Hospital Anxiety and Depression Scale. The association between intermittent hypoxia and poorer glycaemic control (defined by an HbA1c level above the median of 8.5%) was estimated by multivariate logistic regression analysis.
  
  
  RESULTS
  Out of 145 patients studied, 54 (37.2%) had intermittent hypoxia (with sleep apnoea confirmed in 53). Patients with intermittent hypoxia had 0.7% (7.7 mmol/mol) higher median HbA1c levels than patients without intermittent hypoxia (P=0.001). Intermittent hypoxia was associated with poorer glycaemic control after adjusting for obesity, age at onset and duration of diabetes, insulin requirement, sleep quality and depressive mood (OR: 2.31, 95% CI: 1.06-5.04, model adjusted for body mass index; OR: 2.46, 95% CI: 1.13-5.34, model adjusted for waist-to-height ratio).
  
  
  CONCLUSIONS
  Intermittent hypoxia, a consequence of sleep apnoea, is frequent and has a strong independent association with poorer glycaemic control in patients with uncontrolled T2D.
authors: Department of Pneumology, Hospital General de Granollers, Av Francesc Ribas s/n, 08400 Granollers, Barcelona, Spain; Universitat Autònoma de Barcelona, Barcelona, Spain. Electronic address: mtorrella@fhag.es.
authors: M
authors: M
authors: Torrella
authors: Department of Endocrinology, Hospital General de Granollers, Barcelona, Spain.
authors: I
authors: I
authors: Castells
authors: Department of Endocrinology, Hospital General de Granollers, Barcelona, Spain.
authors: G
authors: G
authors: Gimenez-Perez
authors: Department of Endocrinology, Hospital General de Granollers, Barcelona, Spain.
authors: A
authors: A
authors: Recasens
authors: Department of Internal Medicine, Hospital de Sant Celoni, Barcelona, Spain.
authors: M
authors: M
authors: Miquel
authors: Department of Endocrinology, Hospital General de Granollers, Barcelona, Spain.
authors: O
authors: O
authors: Simó
authors: Department of Pneumology, Hospital General de Granollers, Av Francesc Ribas s/n, 08400 Granollers, Barcelona, Spain.
authors: E
authors: E
authors: Barbeta
authors: Universitat Autònoma de Barcelona, Barcelona, Spain; Multidisciplinary Sleep Unit, Department of Pneumology, Hospital Universitari Vall d'Hebron, Barcelona, Spain; CIBER de enfermedades respiratorias (CIBERES), Instituto de Salud Carlos III, Spain.
authors: G
authors: G
authors: Sampol
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications* / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D000860:Hypoxia / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D017286:Polysomnography; D011379:Prognosis; D012891:Sleep Apnea Syndromes / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose
keywords: Diabetes mellitus; Glycosylated haemoglobin; Intermittent hypoxia; Sleep apnoea; Type 2