Physical Activity, Cardiometabolic Health, and Functional Performance Across the Adult Lifespan: An Age-Stratified...

Background: Cardiometabolic risk and physical function are both strongly influenced by physical activity (PA) across the adult lifespan, yet it remains unclear whether this association is uniform across different stages of adulthood in everyday primary care settings, particularly among the oldest patients. Objective: Using a real-world primary care cohort stratified into four adult lifespan groups, we investigated how self-reported PA category was linked to LDL-C concentration and Timed Up and Go (TUG) performance, and formally tested whether these associations differed by age group. Methods: This cross-sectional analysis included 863 adult primary care patients, divided into four clinically meaningful lifespan groups: young adults (18-39 years, n = 277), middle-aged adults (40-59 years, n = 284), younger older adults (60-74 years, n = 166), and older-old adults (≥75 years, n = 136); PA was classified as low, moderate, or high per WHO recommendations. The primary outcomes were LDL-C and TUG. Between-group differences were evaluated with one-way ANOVA (Bonferroni-corrected post hoc tests) and age-specific multivariable linear regression adjusted for BMI, sex, arterial hypertension (AH), and diabetes mellitus (DM); a pooled PA × age-group interaction term formally tested for effect modification by age. Results: Baseline BMI, LDL-C, TUG, sex distribution, AH prevalence, and PA distribution were similar across the four groups, whereas DM prevalence differed modestly (p = 0.033). In every age group, higher PA categories were linked to significantly lower LDL-C (all p ≤ 0.006) and significantly better TUG times (all p < 0.001); PA was the only independent predictor shared by both outcomes across all groups in multivariable models (all p < 0.01). The standardized effect of PA on TUG was greatest among older-old adults (≥75 years: β = -1.609, 95% CI: -2.114 to -1.104, R² = 0.260). Neither the PA-LDL-C nor the PA-TUG interaction with age group reached statistical significance (p = 0.571 and p = 0.349, respectively). Conclusions: Associations between PA and both cardiometabolic and functional performance outcomes were present across all four adult lifespan groups, including adults aged ≥75 years, with no statistically significant age modification detected in this sample. Given the exploratory nature of the interaction analysis and the limited size of the oldest-old subgroup, these results should be regarded as hypothesis-generating rather than conclusive evidence of age-invariance. The pattern seen among older-old adults (≥75 years) reinforces the clinical value of routine PA assessment for evaluating functional health in advanced age. Taken together, these results point to PA assessment as a candidate age-independent component of cardiometabolic and functional health evaluation across the adult lifespan in primary care, a possibility that larger, adequately powered samples should confirm.