Relative fat mass (RFM) is a novel indicator of central adiposity. Cognitive impairment (CI), obesity, and type 2 diabetes mellitus (T2DM) collectively pose substantial public health challenges, contributing to irreversible health consequences and imposing significant economic burdens on healthcare systems worldwide. This study aimed to evaluate the sex-specific association between RFM and CI in middle-aged and older hospitalized patients with T2DM. This cross-sectional study analyzed data from 1328 patients (aged ≥45 years) admitted to the Department of Endocrinology, Tianjin Union Medical Center, between July 2018 and July 2022. CI was defined as a Montreal Cognitive Assessment score < 26. Logistic regression models, restricted cubic spline analyses, and sensitivity analyses were used to assess the association between RFM and CI across sex-specific quartiles. The overall prevalence of CI was 45.6% (605/1,328). The mean age of the study population was 62.4 ± 7.3 years, and 49.3% were female. Among the female participants, we identified a nonlinear inverse J-shaped relationship between RFM and CI (p for nonlinearity = 0.013), characterized by an increasing risk of CI up to an inflection point at an RFM of approximately 43.7, after which the risk plateaued. The third RFM quartile (40.02–42.86) exhibited the highest prevalence of CI (adjusted odds ratio: 2.54, 95% confidence interval: 1.54–4.16). In contrast, no significant association was observed between RFM and CI in males in either unadjusted or fully adjusted models. These findings were consistent across stratified and sensitivity analyses. Among middle-aged and older patients with T2DM, RFM demonstrates a sex-specific, nonlinear association with CI in females. These results highlight the potential utility of RFM as a simple and practical indicator for identifying cognitive risk in female patients with T2DM, supplementing traditional adiposity measures such as body mass index. Not applicable.
Liu et al. (Tue,) studied this question.