We examined the impact of strength fitness and body weight on the redox properties of high-density lipoprotein (HDL) and associations with indices of vascular and metabolic health. Ninety young men were categorized into three groups: 1) overweight untrained (OU; n = 30; BMI 30.7 ± 2.1 kg/m(2)); 2) overweight trained [OT; n = 30; BMI 29.0 ± 1.9; ≥4 d/wk resistance training (RT)]; and 3) lean trained (LT; n = 30; BMI 23.7 ± 1.4; ≥4 d/wk RT). Using a novel assay on the basis of the HDL-mediated rate of oxidation of dihydrorhodamine (DOR), we determined the functional (redox) properties of HDL and examined correlations between DOR and indices of vascular and metabolic health in the cohort. DOR was significantly lower in both trained groups compared with the untrained group (LT, 1.04 ± 0.49; OT, 1.39 ± 0.57; OU, 1.80 ± 0.74; LT vs. OU P < 0.00001; OT vs. OU P = 0.02), however, DOR in the OT group was not significantly different from that of the LT group. DOR was negatively associated with HDL-cholesterol (R = -0.64), relative strength (R = -0.42), sex hormone-binding globulin (R = -0.42), and testosterone (R = -0.35) (all P ≤ 0.001); whereas DOR was positively associated with triglycerides (R = 0.39, P = 0.002), oxidized low-density lipoprotein (R = 0.32), body mass index (R = 0.43), total mass (R = 0.35), total fat mass (R = 0.42), waist circumference (R = 0.45), and trunk fat mass (R = 0.42) (all P ≤ 0.001). Chronic RT is associated with improved HDL redox activity. This may contribute to the beneficial effects of RT on reducing cardiovascular disease risk, irrespective of body weight status.
Keywords: dihydrorhodamine; dysfunctional hdl; exercise; obesity; resistance training.