Context: Although obesity is associated with high bone mass, recent reports suggest an increase in the incidence of fractures in obese patients.
Objectives: The objectives of the study were to evaluate the influence of increasing body fat on bone mineral density (BMD) and to determine the influence of the different adipokines on BMD in frail obese elderly patients.
Design and setting: This is a cross-sectional study of baseline characteristics of elderly obese patients participating in a lifestyle therapy with diet with or without exercise and conducted in a university setting.
Patients: One hundred seventy-three, elderly (≥65 y old), obese (body mass index of ≥30 kg/m(2)) who were mostly frail participated in the study.
Outcome measures: BMD, percentage of total body fat, percentage of fat-free mass, percentage of lean mass, body mass index, adiponectin, leptin, IL-6, bone turnover markers (osteocalcin and C-telopeptide), high-sensitivity C-reactive protein, free estradiol, and 25-hydroxyvitamin D were measured.
Results: Higher tertiles of percentage body fat and lower lean mass were associated with a lower BMD. High-sensitivity C-reactive protein levels were highest in the highest fat tertile (third, 5.5 ± 5.4 vs first, 1.5 ± 1.3 mg/L, P < .05) for women, whereas IL-6 levels were highest in the highest tertile in men (third, 3.5 ± 3.1 vs first, 1.7 ± 0.8 pg/mL, P < .05). Leptin increased with increasing fat tertiles in both genders (P < .05), whereas adiponectin increased with increasing fat tertiles only in men (P < .05). A multivariate analysis revealed adiponectin as an important mediator of the effect of fat mass on BMD. Osteocalcin levels were highest in the highest fat tertile in women but not in men. Physical function test scores decreased with increasing fat tertiles in women (P < .05) but not in men.
Conclusions: Increasing adiposity together with decreasing lean mass is associated with lower BMD, higher adipokine levels, and worsening frailty in elderly obese adults.