Hemoglobin levels and frailty status in generally healthy and active community-dwelling adults age 70 years and older in the three-year DO-HEALTH study

While frailty and anemia are prevalent conditions in aging linked to adverse outcomes, their relationship remains understudied in generally healthy older adults. We conducted a post-hoc observational study among all participants of DO-HEALTH, the largest European clinical trial designed to support healthy aging. Our analysis examined whether baseline hemoglobin levels and anemia are associated with being at least pre-frail at baseline and any yearly follow-up time point over three years. Frailty status was assessed by the Fried frailty phenotype at baseline and at each annual follow-up visit. Participants were considered at least pre-frail by the presence of any frailty domain (fatigue, unintentional weight loss, slowness, weakness, low activity). For both hemoglobin levels and anemia as predictors, we used regression models based on generalized estimating equations controlling for potential confounders. In total, 2,123 of 2,157 participants had available frailty status and hemoglobin levels at baseline and were included in the analysis (mean age 74.9 years; 61.7% women). At baseline, 46.4% (n = 986) were at least pre-frail, while the mean hemoglobin level was 139.7 g/L (SD 12.5), and 6.7% (n = 141) had anemia. In our multivariate prospective analysis, each 10-g/L decrease in baseline hemoglobin levels was associated with 8% higher odds of pre-frailty (adjusted Odds Ratio [aOR] 1.08, 95%CI 1.01-1.16, p 0.02), and baseline anemia was associated with 39% higher odds of pre-frailty over three years (aOR = 1.39, 95%CI 1.02-1.88, p 0.03). In conclusion, our results provide novel insights into the association between hemoglobin levels, anemia, and pre-frailty in generally healthy and active older adults.