Association Between 25-Hydroxyvitamin D and Bone Mineral Density in People With Obstructive Sleep Apnea Syndrome.

The aim of this study was to evaluate the association between bone mineral density (BMD) and 25-hydroxyvitamin D [25(OH) D] levels in patients with obstructive sleep apnea syndrome (OSAS). This study was designed as a cross-sectional and observational study. Patients who underwent polysomnography evaluation were classified as normal, mild, moderate, severe, or position-dependent OSAS, and OSAS + obesity hypoventilation syndrome (OHS). BMD was measured with the dual-energy X-ray absorptiometry method at the femur and lumbar spine. The chemiluminescence microparticle immunoassay was used for the measurement of 25(OH) D levels. A total of 126 patients (73 males, 53 females) with a mean age of 48.55 ± 11.8 years were included. Body mass index was significantly higher in the OSAS + OHS group than in the other groups (p < 0.01). There was no statistically significant difference between the groups in terms of total BMD, T-scores and Z-scores of the lumbar spine, femural neck, and total femur (p > 0.05 for all). Post hoc analyses showed that OSAS + OHS subgroup had lower level of 25(OH) D compared to the normal subjects (p = 0.006). Yet no significant difference was observed between the other OSAS groups. No significant correlation was observed between the apnea hypopnea index, the Epworth Sleepiness Scale scores, desaturation index, and BMD parameters (all for p > 0.05). While 25(OH) D levels were lower in OSAS + OHS patients, there was no statistically significant relationship between OSAS and BMD values.