Bone Abstracts

Introduction: Obstructive sleep apnea (OSA) is a common sleep-related respiratory disorder characterized by repeated episodes of apnea and hypopnea resulting in sleep fragmentation, nocturnal hypoxia and hypercapnia, and excessive daytime sleepiness. OSA has recently become a well-recognized problem in view of its high prevalence in the general population. OSA is associated with many endocrine disorders (hypogonadotropic hypogonadism, hypercortisolism, glucose intolerance). These endocrinopathies may lead to bone loss, with secondary osteoporosis.

The aim of this study is to investigate both the bone metabolic abnormalities and bone mineral density (BMD) in OSA patients compared to individuals without OSA.

Material: The study was conducted on 25 males diagnosed with OSA and 20 healthy males. 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), serum calcium, phosphorus, alkaline phosphatase were evaluated. BMD in the lumbar spine (L1-L4), total hip and femoral neck was measured by dual energy X-ray absorptiometry (DXA).

Results: There were no statistical differences in age, height, weight, blood pressure, and BMI between groups. Except for the HDL-C values, significantly lower in the group with severe OSA, no significant differences in metabolic syndrome parameters were observed. Fibrinogen was significantly higher in the OSA group. Serum ESR levels were not statistically different between groups. We noted significant differences between OSA patients and control subjects with regard to lumbar L1-L4 t-score, lumbar L1-L4 BMD, and femoral neck BMD values (P<0.001). We find significant correlations with lumbar L1-L4 BMD (P<0.05) and lumbar L1-L4 t-score values (P<0.05).

Conclusions: OSA patients might represent a risk group with respect to loss of BMD and bone resorption. It is important to evaluate bone loss in these patients. Our study indicates that there is a relationship between OSA and osteoporosis.