Determinants of Bone Health in Older Adults

The objective of this study was to determine the predictors of bone health in older adults.

A total of 313 subjects older than 65 years (mean age 74.2±6.4 years, 70.6% female) were included in the study. Demographic characteristics of participants such as gait speed, handgrip strength, level of physical activity (using Rapid Assessment of Physical Activity-RAPA scale), vitamin D levels, T scores of femur neck (FN) and lumbar spine (LS) were recorded.

Based on FN, 40.7% of participants had normal T scores whereas 46.2% and 13.1% of them were osteopenic and osteoporotic, respectively. FN was correlated with age (r:-0.184, p<0.001), BMI (r:0.269, p<0.001), and handgrip strength (r:0.149, p:0.009) in addition to the aerobic subscale of RAPA (RAPA-aerobic) (r:-0.133, p:0.02). Similarly, the LS was correlated with female gender (r:-0.207, p<0.001), age (r:0.136, p:0.016), body mass index (BMI) (r:0.246, p<0.001) and handgrip strength (r:0.217, p<0.001). The predictors of bone health were decided upon using multiple logistic regression analysis. The deterministic model consisted of age, gender, BMI, height, weight, handgrip strength, gait speed, RAPA-aerobic and vitamin D. For LS dependent variable, the overall model was significant (F:10.149, p<0.001). However, only two variables were significant predictors in the model ie. weight (β:0.389, p<0.001) and handgrip strength (β=0.186, p<0.001). Similarly for independent variable of FN, the overall model was significant (F:6.525, p<0.001) and only two variables were significant predictors: weight (β:0.371, p<0.001) and RAPA-Aerobic (β:0.148, p:0.009).

Lower levels of body weight, participation in aerobic activity and handgrip strength might be risk factors for deterioration of bone health in older adults.