The Association of Bone Turnover Markers with Muscle Function, Falls, and Frailty in Older Women in Long-Term Care.

BACKGROUND: Osteoporosis and sarcopenia commonly coexist in older adults. There is strong evidence that bone and muscle impact each other through mechanical and biochemical cross-talk.

OBJECTIVES: We sought to investigate the relationship between the markers of bone remodeling including the C-terminal telopeptide of type 1 collagen (CTX) and procollagen type 1 N propeptide (P1NP) with muscle function, falls, and frailty in older women residing in long-term care (LTC) facilities.

DESIGN: A secondary analysis of a randomized controlled trial.

SETTING: Residents of LTC.

PARTICIPANTS: One hundred seventy-eight older women with osteoporosis.

MEASUREMENTS: We measured and analyzed baseline CTX, P1NP, gait speed, sit to stand time, history of falls, and frailty index.

RESULTS: Participants had a mean age of 86.7 years and BMI of 27.6 kg/m2. The correlation (r) of CTX with gait speed and sit to stand test, as indices for muscle function, were -0.193 (p=0.0163) and 0.152 (p=0.0507), respectively. Additionally, CTX level was significantly associated with history of falls (p=0.0068), recurrent falls (p=0.0260), and frail phenotype (p=0.0126). P1NP did not have a significant association with gait speed, sit to stand test, and history of falls; however, it was associated with frail phenotype (p=0.0137). Most findings persisted after adjusting for age.

CONCLUSIONS: In older women residing in LTC facilities, CTX was associated with gait speed, falls history, and frail phenotype, whereas P1NP was only associated with frail phenotype. These findings suggest a relationship between bone remodeling and muscle function.