Hemoglobin Levels and Skeletal Muscle: Results From the InCHIANTI Study

Abstract
Background. Anemia is associated with reduced physical performance and muscle strength. The aim of the study was to explore whether anemia and hemoglobin levels are associated with differences in quantitative and qualitative measures of muscle and fat. Methods. The study sample consisted of 909 participants 65 years and older enrolled in the “Invecchiare in Chianti” (InCHIANTI) study, a prospective population-based study of older people aimed at identifying risk factors for late-life disability. All the analyses were performed considering continuous hemoglobin levels as well as the dichotomous anemia variable (defined according to World Health Organization criteria as hemoglobin Results. Participants were aged 74.8 ± 6.8 years. In our sample, 94 participants (10.3%) were anemic. Hemoglobin levels were significantly associated with muscle density (β = 0.225 [SE, standard error 0.098], p =.02), muscle area/total area ratio (β = 0.778 [SE 0.262], p =.003), fat area/total area ratio (β = −0.869 [SE 0.225]; p <.001). Skeletal muscle strength and muscle density were highly associated with anemia (β = −3.266 [SE 1.173], p =.005 and β = −0.816 [SE 0.374], p =.03, respectively). Results did not change when analyses were rerun in a restricted sample of participants not affected by major medical conditions. Conclusion. The present study shows that hemoglobin levels are associated with the parameters of body composition obtained by pQCT, and that decreases in muscular strength measures occur in the presence of anemia.