Sclerostin tied to lower skeletal mass in healthy people

Serum levels of sclerostin are independently but inversely correlated with skeletal mass in healthy individuals, a new study has found.

Researchers performed a cross-sectional analysis on 240 healthy, nondiabetic individuals whose body composition was measured using dual-energy X-ray absorptiometry. Low muscle mass was defined as <7.0 kg/m² in males and <5.4 kg/m² in females. Serum sclerostin was measured from overnight fasting blood samples using enzyme-linked immunosorbent assays.

Grouping participants into tertiles of skeletal mass index, researchers found that serum sclerostin levels peaked in the bottom tertile and decreased linearly with increasing skeletal mass.

Adjusting for sex, age, body mass index (BMI), smoking status, alcohol consumption and regular exercise, among other variables, did not attenuate this relationship. The overall prevalence rate of low muscle mass was only 11.2 percent.

Serum sclerostin was also significantly and inversely correlated with fasting plasma glucose (FPG) and the ratio between appendicular skeletal muscle mass and the square of height (p<0.001 for both). Direct and significant associations were observed for percent total body fat and bone mineral content (BMC; p<0.001 for both).

“The study shows that osteocyte-derived sclerostin had a significant association with skeletal muscle mass,” said researchers. “Importantly, sclerostin had negative effects on skeletal muscle mass independent of age, sex, BMI, lifestyle parameters, FPG, BMC and total body fat mass.”

Future studies should consider better measurement methods for sclerostin, such as mass spectrometry, they added.