Author Login

Correspondence to Author: Cassandra Jhmith, 

Department/University , Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia.

ABSTRACT: 
Undercarboxylated osteocalcin (ucOC) has been linked to strength and muscle mass maintenance, according to data from animal models. Although there is little information, muscle strength, physical function, and the risk of falls may all be correlated with the human ucOC to total (t)OC ratio. We investigated the hypothesis that, in older women and hospitalizations attributable to falls lasting 15 years, ucOC and the ucOC/tOC ratio are related to muscle function (muscle strength and physical function). As part of the Perth Longitudinal Study of Aging Women, 1261 older women with a mean age of 75.2 ± 2.7 years had their serum tOC and ucOC measured (1998 to 2013). Grip strength and the timedup-and-go (TUG) were measured at baseline and after five years. Hospital Morbidity Data Collection (HCDC) collected hospitalizations related to falls throughout a follow-up of 14.5 years through the Western Data Linkage System Australia. Compared to quartile 1, women with a greater ucOC/tOC ratio (quartile 4) performed less quickly on the TUG at baseline (~0.68 seconds, p .01). Between quartiles, there was no significant difference (p >.05) in grip strength or the 5-year change in TUG and grip. The fear of falling affecting indoor, outdoor, and combination activities varied considerably between quartiles (p .05). Increased walking aid use, fear of falling, and worse TUG performance at baseline and 5-year change in performance were all significantly correlated with higher ucOC/tOC (all p .05). Although there was no 5-year change in strength, higher ucOC was associated with decreased grip strength at baseline (p .05). Hospitalizations due to falls were more common in those with the greatest ucOC/tOC (unadjusted log rank, p =.004), and this difference remained significant even after after correcting for important factors (p =.004, 95% confidence interval [CI] 1.09–1.57, and Hazard Ratio [HR] = 1.31). We found that a significant number of older women with high ucOC/tOC ratios also had decreased physical function, including a long-term reduction in it and a higher risk of hospitalizations due to falls. The risk of harmful falls can be decreased by implementing prevention and intervention techniques as soon as women who are at higher risk are identified. 2020 The American Society of Bone and Mineral Research (ASBMR) All rights reserved.

Citation:

Cassandra Jhmith. A Higher Ratio of Undercarboxylated to Total Osteocalcin Is Linked to Decreased Physical Function and a Higher Rate of Hospitalizations Related to Falls within 15 Years:The Longitudinal Study of Aging Women in Perth. The Journal of Bone and Mineral Research 2024.