Objective: Sclerostin, product of the SOST gene, is an important determinant of bone formation and resorption. Rett patients, frequently present marked decreases in bone mineral density (BMD) beyond that expected from disuse atrophy. However, sclerostin has not been yet examined in Rett subjects as a potential mediator of impaired bone metabolism.
Methods: This study aimed to investigate whether there is any associations between sclerostin levels, body composition and BMD in Rett patients and in healthy controls. We studied 32 Rett girls (mean age 11.8±5.9 years) and 25 age-matched controls. Serum calcium, bone alkaline phosphatase, 25-hydroxyvitamin D and sclerostin were measured in both Rett patients and controls. In all subjects bone mineral density at whole body (BMDWB), BMC-WB and body composition were measured by using a DXA machine (Hologic QDR 4500). QUS parameters were assessed at phalanxes by Bone Profiler-IGEA (amplitude dependent speed of sound: AD-SoS and bone transmission time: BTT).
Results: The values of BMD-WB, AD-SoS and BTT were significantly lower in Rett subjects than in controls; as expected Rett patients had lower weight, lean mass and fat mass. The values of sclerostin were not different in Rett girl respect to healthy controls. Sclerostin showed a significative correlations with BMD-WB that remained significant after adjustment for age (r=0.27; P<0.05). Sclerostin was significally correlated with both lean mass (r=−0.41; P<0.05) and fat mass percentage (r=−0.42; P<0.05). In Rett girls sclerostin serum levels were not predictors of bone status. Instead, we found that in the Rett subjects, weight and age were positively associated with BMD-WB (P<0.05).
Conclusion: Our preliminary study shown that sclerostin presents mild, but significant relationship with both BMD-WB and body composition parameters. Further studies are needed to elucidate the role of sclerostin on bone metabolism and body composition in Rett subjects.
22 - 25 Jun 2013