OR10-5 Body composition in relation to bone microarchitecture among racially/ethnically diverse middle-aged and older men

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: OR10-Osteoporosis
Clinical
Saturday, June 15, 2013: 11:30 AM-1:00 PM
Presentation Start Time: 12:30 PM
Room 121 (Moscone Center)
Andre B. Araujo*1, Nicholas Dagincourt2, Shan Chen2, Gretchen Chiu1, Elizabeth Suarez2, Robert Chang2, Rachael Gerber2, Julia Akeroyd2, Carrie G. Wager2, Benedetta Bartali2 and Mary Larsen Bouxsein3
1New England Research Institutes, Watertown, MA, 2New England Research Institutes, Inc., Watertown, MA, 3Beth Israel Deaconess Med, Boston, MA
Although recent studies and opinion suggest that obesity in men is associated with increased fracture risk, few studies have examined the relationship between body composition and bone microarchitecture. We obtained cross-sectional data from 692 men aged 38-86y  enrolled in the Boston Area Community Health/Bone (BACH/Bone) Survey, a population-based cohort study of racially diverse men. Microarchitecture at the distal radius (N=443) and tibia (N=473) was measured by high-resolution peripheral quantitative computed tomography (HR-pQCT, XtremeCT, Scanco), with CVs <5%. Total body lean mass (LM) and fat mass (FM) were assessed by dual-energy x-ray absorptiometry (DXA). Multivariable linear regression was used to examine the independent associations of LM and FM with cortical and trabecular parameters, controlled for age, race/ethnicity, physical activity, body mass index (BMI), self-rated health, smoking, and cancer. Mean (±SD) age was 58.0±11.6y, with black, Hispanic, and white men representing 30.9%, 29.5%, and 39.6% of the sample, respectively. BMI was 29.0±5.3kg/m2 while FM and LM were 21.85±8.73kg and 54.9±8.1kg, respectively. Bivariate results showed that higher LM was consistently associated with both cortical and trabecular parameters in both the radius and tibia. In contrast, FM was significantly and positively associated only with trabecular parameters in the radius, and exhibited comparatively greater associations with both trabecular and cortical parameters in the distal tibia. These results were largely preserved in multivariable models. For instance, a 10kg increase in LM was associated with a significant increase of 0.07 and 0.22 in trabecular number (per 1/mm) in the distal radius and tibia, respectively, whereas FM was not associated with any parameter in the radius in multivariable models. LM was also significantly associated with higher trabecular density and total area, but lower cortical density and trabecular thickness in the distal tibia. FM was positively associated with trabecular number and negatively associated with cortical density and thickness in the distal tibia. In conclusion, LM and FM appear to play strong, if complex, roles in determining bone microarchitectural properties in middle-aged and older men. Overall, trabecular and cortical parameters in the weight-bearing tibia were more strongly related to body composition than those in the radius, consistent with the important role of mechanical loading influencing the determinants of  bone strength.

Disclosure: ABA: Principal Investigator, Abbott Laboratories, Principal Investigator, GlaxoSmithKline, Consultant, Lilly USA, LLC. Nothing to Disclose: ND, SC, GC, ES, RC, RG, JA, CGW, BB, MLB

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: The BACH/Bone Survey was supported by grant R01AG020727 from the National Institute on Aging (NIA). The content is solely the responsibility of the authors and does not necessarily represent the official views of NIA.