title: Glucose tolerance and weight loss in obese women with obstructive sleep apnea.
abstract: BACKGROUND
  The association of obstructive sleep apnea (OSA) with glucose intolerance and the beneficial effect of lifestyle intervention have been poorly investigated in women particularly before menopausal status. The study explored 1) whether OSA is associated with impaired glucose homeostasis in obese non diabetic premenopausal and menopausal women and 2) the effects of a 3- month lifestyle intervention on glucose homeostasis in OSA women.
  
  
  METHODS
  We consecutively recruited 98 obese women (39 premenopausal) from those referred for a weight loss intervention. Ambulatory nocturnal polysomnography, body composition, oral glucose tolerance test, insulin sensitivity and β cell function were assessed before and after intervention.
  
  
  RESULTS
  41% of premenopausal and 64% of menopausal women had OSA which was associated with worse glucose homeostasis before menopausal status. Mean and minimal nocturnal oxygen saturation (SaO2) was associated with neck/height ratio (NHR), independently of total and central obesity. Mean and minimal nocturnal SaO2 and NHR were correlated with insulin sensitivity and fasting glucose. In multivariate analyses, nocturnal mean SaO2 was negatively and independently correlated with fasting glucose (p<0.0001) and NHR with insulin sensitivity (p<0.0001). In OSA women, the intervention induced a 5% weight reduction and a significant increase in minimal nocturnal SaO2, insulin sensitivity and β cell function. Changes in fasting glucose and insulin sensitivity were associated with those in minimal nocturnal SaO2 (p<0.05) and not with weight loss.
  
  
  CONCLUSIONS
  In obese women, glucose homeostasis worsens due to nocturnal hypoxia and increased neck circumference through mechanisms partially independent of obesity. OSA is more clearly associated with glucose intolerance in premenopausal than in menopausal women. In OSA women, the improvement of nocturnal hypoxia induced by lifestyle modifications is associated with that of glucose homeostasis.
authors.affiliation: Department of Medical Sciences and Rehabilitation, Istituto Auxologico Italiano, Milan, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Gilardini
authors.forename: Carolina
authors.initials: C
authors.lastname: Lombardi
authors.forename: Gabriella
authors.initials: G
authors.lastname: Redaelli
authors.forename: Luciana
authors.initials: L
authors.lastname: Vallone
authors.forename: Andrea
authors.initials: A
authors.lastname: Faini
authors.forename: Paola
authors.initials: P
authors.lastname: Mattaliano
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Parati
authors.forename: Cecilia
authors.initials: C
authors.lastname: Invitti
mesh_terms: D000328:Adult; D000886:Anthropometry; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D008019:Life Style; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000503:physiopathology; D015431:Weight Loss