Anemia can be a debilitating condition for older adults and has been associated with a number of conditions, including cognitive impairment and frailty. The effect of anemia on impairment of muscle strength can reduce a patient’s quality of life significantly. As physical performance already declines as patients age, how strong is the link between anemia and impacted mobility?
In a recent study published in BMC Geriatrics, researchers examined data from the National Health Information Database (NHID) in Korea to determine if there is a link between anemia and mobility capacity. The investigators used the Timed Up and Go (TUG) test, which is an easily administered tool to assess fall risk in older adults.
Participants (N=81,473) aged 65 years or older underwent a physical examination that included the TUG test; 12.6% of participants (n=10,237) met the criteria of having anemia, which was defined as a hemoglobin concentration of less than 13.0 g/dL in men and less than 12.0 g/dL in women.
The researchers found a U-shaped association between TUG test results and hemoglobin levels; lower and higher ranges of hemoglobin were associated with increased time to complete the TUG test. Of the 71,236 participants who did not meet criteria for having anemia, 26.7% (n=18,987) had abnormal TUG test results. Nearly one-third (3151 [30.8%]) of participants with anemia also had abnormal TUG test results. When broken down by sex, 8876 of the 36,290 male participants without anemia (24.5%) had abnormal test results compared with 1140 of the 4120 male participants with anemia (27.7%), and 10,111 of the 34,946 female participants without anemia (28.9%) had abnormal test results compared with 2011 of the 6117 female participants with anemia (32.9%).
The researchers built 4 models to analyze how much more likely patients with anemia were to have abnormal TUG results; one crude model and 3 adjusted models that account for sex, depressive mood, cognitive impairment, and a number of comorbidities. With the crude model, they found that participants with anemia were 22% more likely to have abnormal results; when using adjusted models, they were 19% more likely. Using fully adjusted models, men with anemia were 16% more likely to have abnormal TUG test results and women were 21% more likely.
Although patients with anemia were found to be more likely to have an abnormal test result, a direct causal relationship was not established. Patients with anemia had many other risk factors as well, though a stratified analysis found that anemia and abnormal TUG test results were associated regardless of all examined risk factors aside from cardiovascular disease.
Son KY, Shin DW, Lee JE, Kim SH, Yun JM, Cho B. Association of anemia with mobility capacity in older adults: a Korean nationwide population-based cross-sectional study. BMC Geriatr. 2020;20(1). doi:10.1186/s12877-020-01879-z