No abstract

Body composition changes as a result of ageing may impact the survival of older adults. However, its influence on mortality risk is uncertain. Currently, the best method for body composition analysis in clinical practice is DXA. Nonetheless, the few studies on body composition by DXA and mortality risk in the elderly have some limitations. We investigated the association between body composition by DXA and mortality in a cohort of elderly subjects. Eight hundred thirty‐nine community‐dwelling subjects (516 women, 323 men) ≥ 65 years of age were assessed by a questionnaire, clinical data, laboratory exams, and body composition by DXA at baseline. Total fat and its components (eg, visceral adipose tissue [VAT]) were estimated. Appendicular lean mass (ALM) adjusted for fat and ALM divided by height² was used to ascertain the presence of low muscle mass (LMM). Mortality was recorded during follow‐up. Multivariate logistic regression was used to compute ORs for all‐cause and cardiovascular mortality. Over a mean follow‐up of 4.06 ± 1.07 years, there were 132 (15.7%) deaths. In men, after adjustment for relevant variables, the presence of LMM (OR, 11.36, 95% CI, 2.21 to 58.37, P = 0.004) and VAT (OR, 1.99, 95% CI, 1.38 to 2.87, P < 0.001, for each 100‐g increase) significantly increased all‐cause mortality risk, whereas total fat, measured by the fat mass index, was associated with decreased mortality risk (OR, 0.48, 95% CI, 0.33 to 0.71, P < 0.001). Similar results were observed for cardiovascular mortality. In women, only LMM was a predictor of all‐cause (OR, 62.88, 95% CI, 22.59 to 175.0, P < 0.001) and cardiovascular death (OR, 74.54, 95% CI, 9.72 to 571.46, P < 0.001). LMM ascertained by ALM adjusted for fat and fat mass by itself are associated with all‐cause and cardiovascular mortality risk in the elderly. Visceral and subcutaneous fat have opposite roles on mortality risk in elderly men. Thus, DXA is a promising tool to estimate risk of mortality in the elderly. © 2019 American Society for Bone and Mineral Research.

No abstract

Previous studies have shown a relationship between osteoporosis and increased mortality risk. However, none of these studies performed a concomitant evaluation of the parathyroid hormone (PTH)-calcium-vitamin D axis and bone mass to accurately determine the contribution of each of these parameters to survival in older subjects. Thus, we sought to investigate the association between bone parameters and mortality in a longitudinal, prospective, population-based cohort of 839 elderly subjects. Clinical data (including history of fractures and cardiovascular events) were assessed using a specific questionnaire. Laboratory exams, including serum 25OHD and PTH, were also performed. Bone mineral density (BMD) at the lumbar spine and hip were evaluated using DXA. All analyses were performed at baseline (2005 to 2007). Mortality was recorded during follow-up. Multivariate Cox proportional regression was used to compute hazard ratios for all-cause and cardiovascular mortality. Over a mean 4.06 AE 1.07 years, there were 132 (15.7%) deaths. These individuals were compared to 707 subjects who were alive at the end of the coverage period for mortality data collection. In a multivariate Cox proportional hazards model, age (HR 1.32; 95% CI, 1.13 to 1.55; p ¼ 0.001, for each 5-year increase), male gender (HR 1.90; 95% CI, 1.30 to 2.79; p ¼ 0.001), recurrent falls (more than two in the previous year; HR 1.65; 95% CI, 1.06 to 2.56; p ¼ 0.026), diabetes mellitus (HR 2.17; 95% CI, 1.46 to 3.21; p < 0.001), low physical activity score (HR 1.78; 95% CI, 1.14 to 2.79; p ¼ 0.011), prior cardiovascular event (HR 1.76; 95% CI, 1.18 to 2.63; p ¼ 0.006), total hip BMD (HR 1.41; 95% CI, 1.15 to 1.72; p ¼ 0.001, per each 1 SD decrease), and intact PTH (iPTH) (HR 1.06; 95% CI, 1.04 to 1.08; p < 0.001, per each 10 pg/mL increase) were independently associated with all-cause mortality. The subjects in the highest quartile of PTH (>49 pg/mL) were at a higher risk of cardiovascular death (HR 3.09; 95% CI, 1.36 to 6.99; p ¼ 0.007) compared with the subjects in the lowest quartile (<26 pg/mL). Low BMD and higher PTH were significantly associated with mortality in community-dwelling older adults. These findings support the notion that careful screening of these bone parameters might lead to better management of older patients and improve outcomes in this population.

This study suggests a potential negative effect of visceral adiposity on bone health in nonobese women.