Association between childhood obstructive sleep apnoea and risk of early osteoporosis

Background: Obstructive sleep apnoea syndrome(OSAS) is the most common form of sleep disordered breathing affecting 2-4% children. Repetitive episodes of hypoxia may affect changes in bone metabolism. We aim to study the association of children with OSAS and risk of early osteoporosis. Methods: 86 children between 10-17 years-old suspected of having OSAS and 64 children without OSAS(control group) were included. Polysomnography was performed in all children suspected OSAS. Physical activity scoring for children(PAQ-C), dietary calcium intake(food frequency questionnaire), Vitamin D levels and quantitative calcaneus ultrasound measuring speed of sound(SOS), were collected from all participants(n=150) to identify those at risk for early osteoporosis. Results: There were 72% male and 68% Malay ethnicity. Children from OSAS group were mostly obese(84%) as compared to the control group. In OSAS group, 57% had moderate to severe OSAS (AHI>10 events/hour). Both groups showed equally low activity individuals, score 1 (PAQ-C)(p=0.078). Their mean dietary calcium intake in both groups were similar 1029.88 mg/day ± 100SD. Both groups have insufficient vitamin D level. There are no different in mean Vitamin D(46.59 ng/ml ± 1.05SD) in OSAS group, as compared to control group.(vitamin D 50.03 ng/ml ± 1.53SD)(p = 0.066). Patients with OSAS had a lower SOS compared to non-OSAS patients. (F(2,147) = 11.698, p = Conclusion: Children with OSAS had lower SOS suggesting risk for early osteoporosis. We conclude that using USG calcaneum is noninvasive and can be used to screen risk of osteoporosis in children with OSAS.