Mortality from all-cause and cause-specific in the elderly: Joint implications of anemia and frailty

Background: Anemia is prevalent among older adults, and it contributes to the incidence of frailty. In turn, the frail elderly may be deficient in nutrients, including iron, vitamin B-12, and folate, that can be materials for human blood, as a result of their limited nutrient intake, resulting in anemia. Both anemia and frailty are associated with an increased risk of mortality in elderly adults. However, the combined influence of anemia and frailty on mortality is unclear. Methods: Data obtained from NHANES 2007-2014 were analyzed in this study. Frailty status was determined using a modified Fried Phenotype, and anemia was defined according to the criteria set by the World Health Organization. Public-use Linked Mortality files until December 31, 2019 were available. The weighted Cox proportional hazard regression models were used to estimate separate effects and joint effects of frailty and anemia on all-cause and cause-specific mortality. Results: This study analyzed 6,406 participants aged 60 years or older. Over a 13-year follow-up period, considering participants with no anemia and no frailty as reference, participants with both anemia and frailty had nearly fourfold the all-cause (HR (95% CI): 4.03 (2.95,5.52)), more than four-time the cardiovascular (HR (95% CI): 4.24(2.46,7.32)) mortality risk, and above five-time the non-CVD/non-cancer (HR (95% CI): 5.17 (3.58,7.46)) mortality risk. Conclusions: The study indicated that older adults who exhibit low levels of hemoglobin and frailty are at the greatest risk for all-cause, cardiovascular, cancer, and non-cancer/non-cardiovascular mortality, with the exception of cancer mortality, which was only increased by anemia.