Sex-Specific Associations Between Physical Activity, LDL Cholesterol, and Functional Performance in a Real-World Primary Care Population: A Cross-Sectional Study

Background: Physical activity (PA) is associated with cardiometabolic health and functional performance, yet sex-specific evidence from real-world primary care populations remains limited. Objective: This study evaluated whether associations between self-reported PA categories and LDL-C concentrations and Timed Up and Go (TUG) functional performance differed between males and females in a real-world primary care cohort. Methods: This cross-sectional observational study included 863 adult primary care patients (424 males, 439 females). PA was categorized as low, moderate, or high based on World Health Organization recommendations. LDL-C and TUG were assessed as primary outcomes. Sex-stratified analyses included one-way ANOVA with Bonferroni post hoc comparisons and multivariable linear regression adjusted for age, BMI, arterial hypertension (AH), and diabetes mellitus (DM). An interaction term (PA × sex) was included to formally test for sex modification. Results: Males and females did not differ significantly in age, BMI, LDL-C, TUG, AH prevalence, DM prevalence, or PA distribution (all p > 0.05). Higher PA categories were associated with lower LDL-C in both males (ANOVA F = 13.03, p < 0.001) and females (ANOVA F = 14.92, p < 0.001), and with better TUG performance in both males (F = 44.21, p < 0.001) and females (F = 36.09, p < 0.001). In multivariable regression, PA was the strongest independent predictor of both LDL-C (males: β = −0.301, p < 0.001; females: β = −0.323, p < 0.001) and TUG performance (males: β = −1.235, p < 0.001; females: β = −1.170, p < 0.001) in both sexes. The interaction term (PA × sex) was not statistically significant for either LDL-C (p = 0.804) or TUG (p = 0.944), indicating no significant sex modification of the PA–outcome associations. Conclusions: The associations between self-reported PA and both LDL-C concentrations and TUG functional performance were consistent across sexes in this real-world primary care cohort. These findings support the clinical relevance of routine PA assessment as a sex-independent indicator of cardiometabolic risk and functional health in primary care. Because of the cross-sectional design, causality cannot be established.