ObjectiveTo observe the changes in body mass index (BMI) among male patients aged between 20 and 30 years with fatty liver disease after they undergo an exercise-based weight loss program, this study will map the trajectory of BMI changes and analyze the association between different BMI change trajectories and the degree of insulin resistance.MethodsA total of 148 male patients with fatty liver disease aged 20–30 years who underwent physical examination at the Southern Medical Branch of PLA General Hospital from June 2024 to August 2024 were prospectively enrolled as research subjects. Based on the data of changes in BMI of the patients at baseline, 1, 2 and 3 months after exercise, a growth mixture model (GMM) was used to construct a BMI change trajectory model. Repeated-measures analysis of variance was performed to analyze the levels of homeostasis model assessment of insulin resistance index (HOMA-IR) among patients with different BMI change trajectories. Multiple linear regression analysis was used to explore the association between the BMI change trajectory and HOMA-IR level. ResultsResults of GMM indicated that when three classes were constructed, the model had an entropy value closer to 1, along with smaller values of the Akaike information criterion and Bayesian information criterion. The three classes were named the slow weight loss group, regular weight loss group, and rapid weight loss group, respectively. There were statistically significant differences in uncertain psychological stress scores, sleep quality scores, low density lipoprotein, high density lipoprotein, total cholesterol, triglyceride, fasting plasma glucose, fasting insulin, HOMA-IR, and fatty liver severity among patients with different BMI change trajectories (all P<0.05). Repeated-measures analysis of variance showed that the time effect, intergroup effect, and interaction effect of HOMA-IR among the three groups were all statistically significant (Ftime=3.990, Ptime=0.027; Fgroup=8.880, Pgoup<0.001; Finteraction=5.046, Pinteraction=0.002). These results indicated that HOMA-IR level increased over time, and the impact of the time factor on HOMA-IR varied depending on different BMI change trajectories. Multiple linear regression analysis showed that the HOMA-IR levels were significantly lower in both the regular weight loss group (β=?0.237, P=0.001) and the rapid weight loss group (β=?0.386, P<0.001) compared with the slow weight loss group. ConclusionIn male patients with fatty liver disease aged 20–30 years, there are different trajectories of BMI changes after exercise-induced weight loss, which are associated with insulin resistance.
