Risk factors of osteoporosis in healthy elderly with unrecognized obstructive sleep apnea: role of physical activity.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
['Sforza|Emilia|E|', 'Saint Martin|Magali|M|', 'Thomas|Thierry|T|', 'Collet|Philippe|P|', 'Garet|Martin|M|', 'Barthélémy|Jean Claude|JC|', 'Roche|Frédéric|F|']
D015502:Absorptiometry, Photon D000368:Aged D000886:Anthropometry D015519:Bone Density D003430:Cross-Sectional Studies D015444:Exercise D005260:Female D006801:Humans D008137:Longitudinal Studies D008297:Male D010024:Osteoporosis D015995:Prevalence D012307:Risk Factors D012737:Sex Factors D020181:Sleep Apnea, Obstructive D011795:Surveys and Questionnaires
Osteoporosis Elderly Physical activity OSA Obesity Metabolic factors