Association between anemia and grip strength indices combined with anthropometry in the Korean population

Anemia is common in older people and is associated with low hand grip strength (HGS). However, there is no study of the association of anemia with both absolute and various relative HGS indices. Therefore, the objectives of this study are to examine the association of anemia with absolute and relative HGS indices and to evaluate whether the relative HGS indices are useful as risk indices of anemia. In this large-scale cross-sectional study, we analyzed the association of anemia with anthropometric indices, absolute HGS indices, and relative HGS indices using both crude and adjusted binary logistic regression models. A total of 24,022 participants were included in the final analysis. Anemia was defined as a blood hemoglobin concentration of less than 13.0 g/dL for men, less than 11.0 g/dL for pregnant women, and less than 12.0 g/dL for nonpregnant women. We considered covariates such as residential area, marital status, education level, occupation, household income, alcohol consumption, smoking status, muscular exercise, walking exercise, blood pressure, and age for men, while for women, we also included menopause. The mean ages of the subjects in this study were 51.89 ± 0.19 years in the nonanemic group and 66.56 ± 0.61 in the anemic group in men and 52.55 ± 0.19 in the nonanemic group and 51.85 ± 0.44 in the anemic group in women. The number of anemic patients was 570 (5.5%) in men and 1638 (12%) in women. The mean HGS value in the dominant hand was 38.97 ± 0.11 in the nonanemic group and 30.84 ± 0.38 in the anemic group in men and 22.64 ± 0.07 in the nonanemic group and 21.85 ± 0.16 in the anemic group in women. Age was highly associated with anemia in men but not in women. Absolute HGS indices, such as the dominant HGS index and both HGS indices, were negatively associated with anemia in both sexes in all crude and adjusted models. All relative HGS indices were associated with anemia in men, but in women, only dominant HGS divided by height and both HGS divided by height were related to anemia status in all models. The associations between anemia and absolute and relative HGS indices were significantly high in men, while in women, these associations were of moderate strength. Anemia was negatively associated with HGS in the Korean population. The strengths of the associations of anemia with the absolute and relative HGS indices showing the highest association with anemia were similar. Therefore, there is no need to use relative HGS indices as risk factors for anemia, and absolute HGS indices, as easily obtained and cost-effective measurement, are suitable.