Bone Mineral Density and Parathyroid Hormone as Independent Risk Factors for Mortality in Community-Dwelling Older Adults: A Population-Based Prospective Cohort Study in Brazil. The São Paulo Ageing & Health (SPAH) Study

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.

Association of Appendicular Lean Mass, and Subcutaneous and Visceral Adipose Tissue With Mortality in Older Brazilians: The São Paulo Ageing & Health Study

“…Thus, our study showed that the risks associated with changes in body composition in the elderly are different according to sex, and also that the role of total fat in older adults may be a protective one, contrary to what has been established in the literature for younger populations. These results persisted even after adjusting for known cardiovascular risk factors, including mineral metabolism parameters such as BMD and PTH, which have been previously demonstrated to be predictors of death in this same elderly population …”

“…Subject loss to follow‐up was reasonably low (18%) . Data on potential risk factors for mortality included clinical, laboratory, and DXA variables …”

“…previously demonstrated to be predictors of death in this same elderly population. (37) SPAH is a cohort study that consisted of a sample of community-dwelling older adults. The demographic characteristics of this population were similar to those of the whole Brazilian population over 65 years of age, according to the census of the Brazilian Institute of Geography and Statistics (IBGE).…”

Relationship Between Low Bone Mineral Density and Fractures With Incident Cardiovascular Disease: A Systematic Review and Meta-Analysis

“…Moreover, some publication bias was evident (which we adjusted for) and as anticipated from pooling of observational data, we encountered some heterogeneity, which we were only able to partially explain with meta regression. In addition, although the pooled weight of all studies demonstrated that poor bone health and fracture are typically associated with an increased risk of CVD, some studies did not find such a relationship and one study found that osteoporotic fractures protect against the onset of CVD …”

Parathyroid hormone response to severe vitamin D deficiency is associated with femoral neck bone mineral density: an observational study of 405 women with hip-fracture

“…26,28,29 The negative prognostic role of secondary hyperparathyroidism after hip-fracture is consistent with data in other groups of patients affected by various diseases, and even in the general aged population. 30,31 Notably, PTH excess may worsen sarcopenia, 32 which is highly prevalent in hip-fracture patients. 33 Vitamin D deficiency was highly prevalent in our sample of hip-fracture inpatients, in agreement with the wider literature.…”