Physical Activity and Liver Fibrosis: A Stratified Analysis by Obesity and Diabetes Status

<b>Background/Objectives</b>: We investigated the association between leisure-time physical activity (LTPA) and liver fibrosis, and whether this relationship differs by obesity and diabetes status. <b>Methods</b>: We conducted a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) 2017-March 2020 cycle. LTPA was assessed using the Global Physical Activity Questionnaire (GPAQ) and classified as physically active if engaging in ≥600 metabolic equivalent (MET)-minutes per week of moderate-to-vigorous activity, or inactive. Clinically significant liver fibrosis was defined as liver stiffness measurement (LSM) ≥ 8.0 kPa on transient elastography. Multivariable logistic and linear regression models estimated adjusted odds ratios (ORs) for significant liver fibrosis, with additional subgroup analyses according to obesity and diabetes status. <b>Results</b>: In 7662 U.S. adults, physically active participants (n = 2721) had a lower prevalence of significant fibrosis than inactive individuals (5.4% vs. 11.4%, <i>p</i> < 0.001). In multivariable analysis, Participants who were physically active were associated with 42% lower odds of having fibrosis (OR 0.58, 95% confidence interval [CI] 0.41-0.82; <i>p</i> = 0.004). This association remained consistent in subgroup analyses stratified by obesity and diabetes status, even in the non-obese subgroup with body mass index (BMI) < 30 kg/m² (OR 0.54, 95% CI 0.32-0.91; <i>p</i> = 0.022) and the non-diabetic subgroup (OR 0.59, 95% CI 0.39-0.90; <i>p</i> = 0.016). <b>Conclusions</b>: Regular moderate-to-vigorous LTPA was independently associated with lower likelihood of clinically significant liver fibrosis. This beneficial association was significant regardless of obesity or diabetes status, suggesting that LTPA may play a clinically meaningful role in populations at high risk for progressive liver disease.