Sex-specific Associations Between Soft Tissue Body Composition and Bone Mineral Density Among Older Adults

Aim: This paper examines sex specific associations between soft tissue body composition (lean and fat mass) and bone mineral density among older adults.

Subjects And Methods: Two hundred and eighty-two subjects (152 females and 130 males) aged 60-92 years ((x))= 71.9 ± 7.9) were enrolled. Body composition of the whole body and bone density (BMD) of the whole body and the femoral neckwere measured by dual energy x-ray absorptiometry. Body mass index (BMI), relative appendicular skeletal muscle mass (RASM) and relative total muscle mass (RTSM) were calculated. Subjects were categorized based on sarcopenia, i.e. reduced appendicular skeletal muscle mass, osteopenia and osteoporosis. BMD of the femoral neck was used to categorize osteopenia and osteoporosis.

Results: Sex-specific correlation patterns between soft tissue body composition and bone density were observed. Lean body mass (RASM and RTSM) correlated significantly with total and femoral neck bone density in men, absolute and relative fat mass were significantly related to whole and femoral neck bone density among women only. Sarcopenic men suffered significantly more frequently from osteopenia and osteoporosis than their non-sarcopenic counterparts. Among females sarcopenia was not related to reduced bone density.

Conclusions: The impact of soft tissue body composition on bone density is different among men and women at older ages. A significant relation between muscle mass and bone density is found among elderly males only.