title: Obstructive sleep apnea and the metabolic syndrome in an elderly healthy population: the SYNAPSE cohort.
abstract: BACKGROUND
  Obstructive sleep apnea syndrome (OSA) has been recently considered as a cause and a component of the metabolic syndrome (MetS), previous studies showing the presence of OSA in about half of middle-aged patients having MetS. To date, no study has considered the association of OSA and MetS in the elderly. In this study we examine the prevalence of MetS and its strength association among healthy elderly OSA subjects.
  
  
  METHODS
  A cohort of 806 subjects aged 68.5 years, participants of a 7-year follow-up study, was examined. All subjects underwent clinical evaluation, blood sample measurements, and an at-home polygraphy. OSA was assessed as an apnea/hypopnea index (AHI) >15, and MetS was diagnosed according to the Adult Treatment Panel III.
  
  
  RESULTS
  In the total group, 9.8% of cases met criteria for MetS with a prevalence similar in men and women. Of the entire group with Mets, 51.3% were women and 48.7% men. OSA was diagnosed in 55.9% of the sample, and among the OSA group, 12.5% had MetS. Oxyhemoglobin desaturation index (ODI, p < 0.0001) and AHI (p = 0.003) were found significantly higher in subjects with MetS than in those without it. Most of MetS components were significantly associated with AHI and ODI, the relationship stronger with ODI. After adjustment for covariables such as obesity, gender, and presence of diabetes, ODI was independently associated with three MetS components, glycemia (p < 0.0001), hypertension (p = 0.002), and triglyceride levels (p = 0.02). Sleepiness, autonomic arousal index, and sleep duration had no effect on the metabolic parameters.
  
  
  CONCLUSIONS
  In elderly subjects, the association between OSA and MetS was stronger for hyperglycemia and hypertension. Among factors explaining this association, hypoxemia appears to be the most important factor without any effect of indices of sleep fragmentation, sleep duration, and sleepiness.
authors.affiliation: Clinical and Exercise Physiology Laboratory, University Hospital and Jean Monnet University, PRES from Lyon, EA 4607, Saint-Etienne, France.
authors.forename: Hourfil-Gabin Ntougou
authors.initials: HG
authors.lastname: Assoumou
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Gaspoz
authors.forename: Emilia
authors.initials: E
authors.lastname: Sforza
authors.forename: Vincent
authors.initials: V
authors.lastname: Pichot
authors.forename: Sébastien
authors.initials: S
authors.lastname: Celle
authors.forename: Delphine
authors.initials: D
authors.lastname: Maudoux
authors.forename: Michel
authors.initials: M
authors.lastname: Kossovsky
authors.forename: Florian
authors.initials: F
authors.lastname: Chouchou
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Barthelemy
authors.forename: Frédéric
authors.initials: F
authors.lastname: Roche
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005602:France; D006801:Humans; D006943:Hyperglycemia / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D008297:Male; D024821:Metabolic Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D010108:Oxyhemoglobins / Q000378:metabolism; D017286:Polysomnography; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology*; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D010108:Oxyhemoglobins; D014280:Triglycerides