title: Risk factors of osteoporosis in healthy elderly with unrecognized obstructive sleep apnea: role of physical activity.
abstract: Several studies suggest a relationship between bone mineral density (BMD) anthropometric and metabolic variables, and obstructive sleep apnea (OSA); all of these factors have an effect on osteoporosis (OS) risk. This cross-sectional study explores these associations in a large sample of older subjects with and without OSA.
  
  
  
  Volunteers were recruited from the PROgnostic indicator OF cardiovascular and cerebrovascular events survey. A total of 461 subjects, aged 68.7 ± 0.8 years, were examined, blood samples were taken, and they were subjected to home polygraphy, assessment of daily energy expenditure (DEE), and dual-energy X-ray absorptiometry.
  
  
  
  Osteopenia (OP) was detected in 44% of subjects at the femoral and 39% at the vertebral level, while the prevalence of OS was lower at the femoral (4%) and vertebral (12%) levels. As expected, women had a higher prevalence of OP and OS. Subjects with OP and OS had a tendency to have lower DEE and values of obesity, apnea-hypopnea index (AHI), and indices of hypoxemia (ODI). At the correlation analyses, anthropometric factors and DEE were significantly related to BMD with a slight effect of indices of OSA severity. After adjustment for confounding variables, univariate and multivariate regression analyses showed a strong significant association between femoral and lumbar BMD and T-score and DEE without contribution of metabolic data and with a slight negative effect of respiratory factors.
  
  
  
  In this sample of the elderly, physical activity was the best predictor of OS with a slight effect of body mass index. The indices of OSA confirm their protective effect on bone mineral density.
authors.affiliation: Service de Physiologie Clinique et de l'Exercice, Faculté de Médecine Jacques Lisfranc, COMUE de Lyon, Université Jean Monnet, Saint-Etienne, France. Electronic address: emilia.sforza@gmail.com.
authors.forename: Emilia
authors.initials: E
authors.lastname: Sforza
authors.affiliation: Service de Physiologie Clinique et de l'Exercice, Faculté de Médecine Jacques Lisfranc, COMUE de Lyon, Université Jean Monnet, Saint-Etienne, France.
authors.forename: Magali
authors.initials: M
authors.lastname: Saint Martin
authors.affiliation: Service de Rhumatologie, CHU Saint-Etienne, Faculté de Médecine Jacques Lisfranc, Inserm U1059 LBTO, COMUE de Lyon, Université Jean Monnet, Saint-Etienne, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Thomas
authors.affiliation: Service de Rhumatologie, CHU Saint-Etienne, Faculté de Médecine Jacques Lisfranc, Inserm U1059 LBTO, COMUE de Lyon, Université Jean Monnet, Saint-Etienne, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Collet
authors.affiliation: Service de Physiologie Clinique et de l'Exercice, Faculté de Médecine Jacques Lisfranc, COMUE de Lyon, Université Jean Monnet, Saint-Etienne, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Garet
authors.affiliation: Service de Physiologie Clinique et de l'Exercice, Faculté de Médecine Jacques Lisfranc, COMUE de Lyon, Université Jean Monnet, Saint-Etienne, France.
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Barthélémy
authors.affiliation: Service de Physiologie Clinique et de l'Exercice, Faculté de Médecine Jacques Lisfranc, COMUE de Lyon, Université Jean Monnet, Saint-Etienne, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Roche
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000886:Anthropometry; D015519:Bone Density / Q000502:physiology; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010024:Osteoporosis / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis*; D011795:Surveys and Questionnaires
keywords: Elderly; Metabolic factors; OSA; Obesity; Osteoporosis; Physical activity