Exercise-induced hypertension, atherogenic lipid subfractions, and cardiorespiratory fitness in marathon runners

Objective Exercise-induced hypertension (EIH), defined by an exaggerated exercise systolic blood pressure response, has been linked to cardiovascular events. This study examined whether EIH is associated with atherogenic lipid subfractions and whether cardiorespiratory fitness (CRF) relates to lipid particle characteristics in male marathon runners. Methods In this cross-sectional study, 51 male marathon runners aged 40–65 years were tested between March and September 2023 at the Exercise Physiology Laboratory, Sungshin Women's University, Seoul, South Korea. Participants were classified as having EIH ( n = 29, maximal systolic blood pressure ≥ 210 mmHg) or a normal response ( n = 22). Lipid subfractions, including small dense low-density lipoprotein (LDL), were assessed by polyacrylamide gel electrophoresis, and CRF was measured by maximal oxygen uptake (VO₂max). Results Lipid subfractions did not differ between EIH and normotensive runners, including small dense LDL and mean LDL particle size (all p > 0.05). Higher VO₂max was associated with lower small dense LDL ( r = −0.41, p < 0.01) and triglycerides ( r = −0.36, p < 0.01), and higher HDL-cholesterol ( r = 0.33, p = 0.02) and mean LDL particle size ( r = 0.39, p < 0.01). Conclusions Among male marathon runners, EIH was not associated with adverse atherogenic lipid subfractions, whereas higher CRF correlated with more favorable lipid particle profiles, suggesting fitness-related metabolic adaptations may mitigate lipid-mediated cardiovascular risk.