title: Effect of glycemic control on nocturnal arterial oxygen saturation: a case-control study in type 2 diabetic patients.
abstract: BACKGROUND
  There is growing evidence suggesting a deleterious effect of type 2 diabetes on lung function and sleep breathing. The aim of this case-control study was to evaluate whether or not an improvement in glycemic control could arrest or ameliorate nocturnal hypoxemia in type 2 diabetes.
  
  
  METHODS
  Thirty patients with type 2 diabetes with HbA1c ≥8% (cases) and 10 non-diabetic subjects were analyzed. Controls were closely matched to cases by age, gender, body mass index, and neck circumference. The nocturnal oxygen desaturation index (ODI) was calculated at baseline and 5 days after blood glucose improvement with pharmacological intervention. Four different oxygen desaturation thresholds (reductions in SaO2  ≥ 3%, 4%, 6%, and 8%) as indicators of hypoxemia severity (ODI-3%, ODI-4%, ODI-6%, ODI-8%) were used.
  
  
  RESULTS
  At baseline, patients with diabetes showed a higher number of ODI-3%, ODI-4%, and ODI-6% in comparison with controls. A significant reduction in ODI-3% (29.7 [4.8-107.9] events per hour at baseline versus 24.6 [3.1-97.7] e/h at discharge, P < 0.001), ODI-4% (21.7 [1.6-79.3] versus 14.7 [0.3- 79.4], P = 0.003), ODI-6% (9.3 [0.3-71.8] versus 4.0 [0.0-73.7], P = 0.001), and ODI-8% (4.1 [0.0-64.3] versus 1.1 [0.0-69.8], P = 0.033) was observed in patients with diabetes after 5 days of follow-up. However, no changes in ODI events were observed in non-diabetic patients after the same period. No significant changes in weight were observed in either group.
  
  
  CONCLUSIONS
  Glycemic control improvement significantly reduces the increased number of nocturnal oxygen desaturations that exist in type 2 diabetes. Although the mechanisms are not yet fully understood, the rapid effect without changes in body weight suggests a central mechanism involving respiratory center output.
authors.affiliation: CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ISCIII), Endocrinology Department, Diabetes and Metabolism Research Unit, Universitat Autònoma de Barcelona, Barcelona, Spain; Endocrinology and Nutrition Department, Arnau de Vilanova University Hospital, Universitat de Lleida, Lleida, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Lecube
authors.forename: Andreea
authors.initials: A
authors.lastname: Ciudin
authors.forename: Gabriel
authors.initials: G
authors.lastname: Sampol
authors.forename: Silvia
authors.initials: S
authors.lastname: Valladares
authors.forename: Cristina
authors.initials: C
authors.lastname: Hernández
authors.forename: Rafael
authors.initials: R
authors.lastname: Simó
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D001835:Body Weight; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D011379:Prognosis
chemical_list: D001786:Blood Glucose; D010100:Oxygen
keywords: apnea; diabetic complications; hypoxia; lung; metabolic control; type 2 diabetes; 关键词：呼吸暂停，糖尿病并发症，缺氧，肺，代谢控制，2型糖尿病