Body composition changes with age have gender-specific impacts on bone mineral density

Area of Science:

• Gerontology
• Orthopedics
• Public Health

Background:

• Factors like body weight, smoking, alcohol, physical activity, and diet influence bone mineral density (BMD).
• Body weight's impact on BMD is well-known, with ongoing debate regarding the roles of lean body mass (LBM) and fat mass (FM).
• Advancements in peripheral densitometry enable large-scale epidemiological studies on osteoporosis.

Purpose of the Study:

• To investigate the relative contributions of LBM and FM to BMD in healthy Korean adults.
• To identify independent determinants of BMD in men and women.

Main Methods:

• Selected 402 age- and weight-matched Korean subjects over 45 years old from a population-based cohort.
• Measured BMD using peripheral dual-energy X-ray absorptiometry (DEXA) and body composition via bioelectrical impedance.
• Collected sociodemographic data and physical activity information through questionnaires and interviews.

Main Results:

• In men, LBM was an independent determinant of BMD. In women, both LBM and FM were equally important independent determinants.
• Age, weight, BMI, LBM, FM, physical activity, smoking, alcohol, and education correlated with BMD in men.
• Age, weight, BMI, LBM, FM, education, years since menopause, deliveries, and breastfeeding correlated with BMD in women.

Conclusions:

• LBM is a key contributor to BMD in men, whereas both LBM and FM are equally important in women.
• Differences in body composition changes with age between sexes contribute to these findings.
• Augmenting muscle mass in men and maintaining optimal weight in women are strategies to prevent osteoporosis.