Ratio of Fat-Free Mass to Fat Mass is Associated with Physical Performance in Patients with Type 2 Diabetes Mellitus

Sung-Jui Hsiang¹Fu-Siang Ke¹Tsung-Hui Wu¹Shiow-Chwen Tsai²Chii-Min Hwu¹Guan-Yu Su^1*

• ¹Section of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
• ²Department of Sports Sciences, University of Taipei, Taipei, Taiwan

The ratio of fat-free mass (FFM) to fat mass (FM) is a key indicator of body composition. Evidence suggests that the FFM/FM ratio is more reliable than body mass index in predicting functional outcomes in older adults with prefrailty. Individuals with type 2 diabetes mellitus (T2DM) exhibit higher FM and faster lean mass loss than do those without T2DM. In this study, we determined whether the FFM/FM ratio can predict functional outcomes in patients with T2DM.Methods: This study included patients aged ≥50 years who received a T2DM diagnosis at least 1 year before the initiation of this study. They were recruited from Taipei Veterans General Hospital, Taiwan, between April 2019 and December 2023. Body composition was assessed using InBody 3.0. Physical performance was evaluated through the Short Physical Performance Battery and gait speed measurement. The FFM/FM ratio was calculated using established formulas. Stepwise multiple regression was performed to identify the predictors of the FFM/FM ratio in patients stratified by sex.The study cohort comprised 166 men and 173 women. The patients were stratified into 3 groups by the FFM/FM ratio: high-tertile, mid-tertile, and low-tertile groups. In both sexes, the hightertile group exhibited superior physical performance than did the other groups, as indicated by higher Short Physical Performance Battery scores, better performance in the 30-second chair stand test, faster gait speed in the 6-m walk, and shorter completion time in the timed up and go test. In men, waist circumference, upper arm circumference, age, logarithmic transformation of alanine transaminase level, and uric acid level emerged as independent predictors of the FFM/FM ratio. In women, waist circumference, upper arm circumference, age, and uric acid level emerged as independent predictors; notably, logarithmic transformation of alanine transaminase level was not included in the regression model.The present study revealed that a decreased FFM/FM ratio is associated with suboptimal physical performance in patients with T2DM, and this ratio may provide meaningful clinical benefits in targeting body composition in this population.