Markers of nutritional status and mortality in older adults: The role of anemia and hypoalbuminemia.

Aim: The aim of the present study was to analyze the impact of anemia and hypoalbuminemia on mortality in a 5-year period.

Methods: This was longitudinal population-based observational survey part of the Saúde, Bem-Estar e Envelhecimento study (Health, Well-being and Aging), carried out with 1256 older adults from the third wave of the cohort, followed for 5 years, when they were contacted for the fourth wave, in Sao Paulo, Brazil. Anemia was defined when hemoglobin was <12 g/dL for women and <13 g/dL for men, and hypoalbuminemia when serum albumin was <3.5 g/dL. Survival functions were estimated according to nutritional status in four groups: (i) without nutritional alteration; (ii) anemia only; (iii) hypoalbuminemia only; and (iv) anemia and hypoalbuminemia. Hazard ratios were calculated, following the Cox proportional hazards model, controlling for baseline covariates. All analyses considered sample weights, and were carried out using the Stata 12.

Results: After the 5-year period, 12.3% of the participants died, and 8.2% were lost to follow up. Those who died had lower hemoglobin and albumin concentrations (13.4 g/dL and 3.7 g/dL) compared with survivors (14.3d/dL and 3.9 g/dL; P < 0.001). The crude death rate was 27.6/1000 person-years for participants in group i, 124.3 in group ii, 116.0 in group iii and 222.8 in group iv (P < 0.001). In the final Cox models, group 2 and 3 had a similar effect (hazard ratio 2.23, P = 0.020; 2.53, P = 0.005; respectively) and group 4 had a higher risk (hazard ratio 3.36; P = 0.004).

Conclusions: Anemia and hypoalbuminemia are important markers for death in older adults, and have an additive effect on mortality. Because they are common and cost-effective biomarkers, their use should be encouraged in geriatric evaluation for all health professionals and in population settings, such as primary care. Geriatr Gerontol Int 2018; 18: 177-182.