Zusammenfassung

PURPOSE: To determine associations of weight loss with bone strength and microarchitecture. METHODS: We used data from 1723 community-dwelling men (mean age 84.5 years) who attended the MrOS study Year (Y) 14 exam and had high resolution peripheral quantitative computed tomography (HR-pQCT) scans at ≥1 skeletal sites (distal tibia, distal radius, or diaphyseal tibia). Weight change from Y7 to Y14 exams (mean 7.3 years between exams) was classified as moderate weight loss (loss ≥10%), mild weight loss (loss 5% to <10%), stable weight (<5% change) or weight gain (gain ≥5%). Mean HR-pQCT parameters (95%CI) were calculated by weight change category using linear regression models adjusted for age, race, site, health status, body mass index, limb length and physical activity. The primary outcome measure was estimated failure load. RESULTS: There was a non-linear association of weight change with failure load at each skeletal site with different associations for weight loss vs. weight gain (p <0.03). Failure load and total bone mineral density (BMD) at distal sites were lower with greater weight loss with 7.0–7.6% lower failure loads and 4.3–5.8% lower BMDs among men with moderate weight loss compared to those with stable weight (p <0.01, both comparisons). Cortical, but not trabecular, BMDs at distal sites were lower with greater weight loss. Greater weight loss was associated with lower cortical thickness at all three skeletal sites. CONCLUSION: Weight loss in men in late life is associated lower peripheral bone strength and total BMD with global measures reflecting cortical but not trabecular parameters.