Evaluating the Association between Obstructive Sleep Apnea and Bone Density Using Two Consecutive Computed Tomography Scans Obtained for Other Indications
3Sleep Wake Disorders Unit, Soroka Medical Center, Israel
Objectives: Normative ranges of L1 vertebra trabecular attenuation serve as a quick reference at routine CT to identify adults with low bone mineral density. Some studies concluded that OSA can modulate bone metabolism
the aim was to show whether there is a decrease in bone Density (By measuring hounsfield unit) between two consecutive computed tomography scans in the adult population who underwent polysomnographic evaluation
Methods: Lumbar (L1) and Thoracic (T12) veretbra density were evaluated by measuring HU in 202 patients which underwent PSG test and two consecutive abdominal "opportunistic" CT scans in our institution. patients with known pathologies which can influence bone metabolism were exculded
We also examined the density difference between two consecutive abdomen CT in a control group which included random adult population which didn`t undergone PSG. Same exclusion criteria were applicable as the study group.
Results: 174 patients were enrolled in the study group and 115 patients in the contorl
No significant differences were found in age and gender distribution between no OSA and OSA groups. The prevalence of hypertension and cardiovascular disease was significantly higher in OSA patients
Both OSA and OSA groups have similar median and range of time between the first and second CT examinations of 1299 days and 1309 days
BMD of L1 BMD and T12 BMD strongly correlate during the first and second CT examinations.
Patients with OSA vs. no OSA had lower L1 BMD at second CT examination (p < 0.05). Interestingly BMD difference in T12 and L1 significantly increased only in men with OSA.
Conclusion: BMD was lower in the OSA group than in the control group and was decreasing over time. There is still a question wheter IV injection influences the value of the HU and this should be taken in consideration when approaching this tool for osteoporosis screening