The effect of body mass index on bone density by age distribution in women

Osteoporosis significantly affects public health, especially among postmenopausal women, by reducing bone mass and increasing the risk of fractures. While the influence of body mass index (BMI) on Bone Mineral Density (BMD) is acknowledged, the specific age range in which BMI most significantly affects bone density remains unclear. This study aims to explore the relationship between BMI and BMD in different age groups to identify potential age-specific risk factors for osteoporosis. In a retrospective cohort study at the University of Health Sciences Turkey, X Hospital, DXA scans of 240 postmenopausal women aged 40 to 80 were analyzed between February 2018 and February 2020. The study used statistical analyses, including ANCOVA and Pearson correlation, to investigate the effects of BMI on BMD, adjusting for age and other variables. Analysis revealed a complex interaction between BMI and BMD. Controlling for BMI showed a statistically significant difference in measurements of lumbar T, neck T, and trochanter T between age groups (P < .05). Specifically, bone density in the 40 to 49 age range was found to be lower when adjusted for BMI, suggesting that the protective effect of higher BMI is less pronounced in younger postmenopausal ages but decreases less negatively in older groups. The impact of BMI on trochanter T measurements was markedly different, increasing in the 40 to 49 age group, while decreasing in others. BMI, along with body weight and age, are important determinants of BMD, but not the sole factors influencing bone loss. The study highlights the need for a personalized approach to osteoporosis risk, considering a broader spectrum of genetic, hormonal and lifestyle factors. It recommends further evaluation of other risk factors in larger cohorts and emphasizes the importance of future longitudinal research to elucidate the dynamic relationship between BMI and BMD over time.