Reducing Undercarboxylated Osteocalcin With Vitamin K Supplementation Does Not Promote Lean Tissue Loss or Fat Gain Over 3 Years in Older Women and Men: A Randomized Controlled Trial : EFFECT OF REDUCING UNDERCARBOXYLATED OC ON LEAN TISSUE AND FAT MASS

Abstract

<p class="first" id="P1">Osteocalcin (OC) is a vitamin K-dependent protein synthesized during bone formation. Mice injected with the undercarboxylated form of OC (ucOC) had more skeletal muscle mass and less fat mass than sham-treated controls, suggesting a unique metabolic role for ucOC. UcOC decreases in response to vitamin K supplementation. Our objective was to determine the effect of reducing ucOC on change in lean tissue and fat mass in older community-dwelling adults (n=401, mean±SD 69±6 years) using data from a randomized controlled trial of vitamin K supplementation Over 3 years, serum ucOC was reduced by 58% in women and by 61% in men randomized to vitamin K, while in the control group ucOC decreased by 1% in women and 4% in men (supplementation*time p&lt;0.001 in men and women). However, there were no differences in the change in appendicular lean mass (calculated as arm lean mass + leg lean mass)or total body fat mass between women randomized to vitamin K and control over 3 years (supplementation*time p-values all ≥0.18)or between men randomized to vitamin K and control (supplementation*time p-values all ≥0.54). Consistent with these findings, ucOC was not associated cross-sectionally with appendicular lean mass or fat mass in men or women after adjustment for total OC at baseline (all p ≥0.12). These findings indicate the undercarboxylated form of OC is not implicated in age-related changes in skeletal muscle or adipose tissue mass in older community-dwelling adults. </p>