Obstructive sleep apnea and bone mineral density in obese patients

Abstract

Stefania Mariani,1 Daniela Fiore,1 Laura Varone,2 Sabrina Basciani,1 Agnese Persichetti,1 Mikiko Watanabe,1 Maurizio Saponara,3 Giovanni Spera,1 Costanzo Moretti,4 Lucio Gnessi11Department of Experimental Medicine, Section of Medical Physiopathology and Endocrinology, Sapienza University of Rome, Italy; 2Department of Environmental Biology, Sapienza University of Rome, Italy; 3Department of Otolaryngology, Audiology and Phonation, Sapienza University of Rome, Italy; 4Division of Endocrinology, Department of System Medicine, Section of Reproductive Endocrinology University of TorVergata, Fatebenefratelli Hospital "San Giovanni Calibita" Rome, ItalyContext: Obesity and its co-morbidities may adversely affect bone mineral density (BMD). Obstructive sleep apnea (OSA) is a major complication of obesity. To date, the effects of OSA on BMD in obese patients have been poorly studied.Objective: To examine whether the severity of OSA independently correlates with BMD in obese patients.Methods: One hundred and fifteen obese subjects with OSA (Apnea/Hypopnea Index [AHI] ≥5 events per hour) were included in the study. BMD was measured at lumbar spine, total hip, and femoral neck by dual energy X-ray absorptiometry. Body mass index, lean mass, and representative measures of metabolic syndrome (waist circumference, fasting plasma glucose, blood pressure, HDL-cholesterol, triglycerides) and inflammation (ESR, CRP, fibrinogen) were also evaluated.Results: BMD did not differ among obese individuals regardless of OSA severity. Correlation coefficient analysis for all the covariates showed a lack of association between AHI and BMD that was strongly influenced by age and weight.Conclusion: Our study does not support an independent association between AHI and BMD in obese patients. Controlled studies involving a greater number of patients are warranted.Keywords: obesity, polysomnography, metabolic syndrome