Hemoglobin concentration is associated with self-reported disability and reduced physical performance in a community dwelling population of nonagenarians: the Mugello Study

People aged 90 and older represent a fast-growing population segment who deserve specific attention and research. Aging is associated with a progressive decrease in hemoglobin concentration, which predicts adverse outcome, such as mortality, morbidity, frailty and disability. Whether this association is independent from increased prevalence of comorbidity, causing both anemia and reduced physical function is yet under debate. The aim of this study is to explore the relationship between hemoglobin concentration and self-reported disability and reduced physical performance in a community dwelling population of nonagenarians. Data presented were collected in the framework of the Mugello Study, a clinical epidemiologic survey of nonagenarians living in the Mugello area (Tuscany, Italy). 251 persons (177 women, age 93.2 +/- 3.3 years; 74 men, age 92.2 +/- 2.5 years) underwent a blood draw. Along with hemoglobin concentration, self-reported disability (basic and instrumental activities of daily living), physical performance (Short Physical Performance Battery), self-reported physical activity and muscular strength (handgrip measurement) were assessed. Covariates, inherent sociodemographic and health indicators and comorbidities were also included in the analysis. This study confirms that anemia is very common in the oldest old, with a significantly higher prevalence in males (50% in men vs 24% in women). Multiple linear regression analysis, including all the comorbid conditions as confounding factors, shows that hemoglobin concentration is independently associated with handgrip strength, self-reported physical activity and disability in dressing, and taking a shower/bath. In conclusion, results from this study confirm that in the oldest old, low hemoglobin concentration is strongly associated with self-reported disability and decline of physical performance independent of comorbidity.