P1503A one-year intervention combining weight loss and exercise increases the proportion of lipoprotein constituted by HDL and HDL particle size

Abstract

Background: Dyslipidaemia is pivotal in the development of atherosclerosis and coronary artery disease (CAD). We wished to compare the effect of weight loss induced by a low energy diet (LED) combined with aerobic interval training (AIT) or intensive AIT alone on lipoprotein distribution and particle size in an overweight, sedentary population with CAD. Methods: 70 CAD patients, BMI 28-40 kg/m2 and age 45-75 years were randomised (1:1) to 1) 12 weeks' AIT at 90% of peak heart rate three times/week followed by 40 weeks' AIT twice weekly or 2) an LED (800-1000 kcal/day) for 8-10 weeks followed by a weight maintenance programme including AIT twice weekly. Continuous density gradient ultracentrifugation of NBD-ceramide labelled lipoproteins was used to estimate total and subclass amounts (pixels); relative amounts were given as % total AUC. Lipoprotein particle size was calculated based on known relationships between particle densities and particle diameter. Results: 26 (74%) AIT and 29 (83%) LED+AIT participants completed the intervention but one was excluded in each group due to altered statin treatment. At baseline mean age was 63 years (SD 6.3), body weight was 95.9 kg (SD 12.2), BMI was 32.2 kg/m2 (SD 3.1) and VO2peak was 20.7 mL O2/kg/min (SD 4.9). All participants had the atherogenic LDL pattern A (mean LDL size <25.5 nm). No significant changes were seen in the amount of LDL, HDL or total lipoprotein or LDL particle size; however, in the LED+AIT group the proportion of total lipoprotein constituted by HDL was increased (baseline: 56.4%, difference: 2.5% (0.7%; 4.3%) P=0.005). Moreover, LED+AIT increased the contribution of large buoyant HDL particles to the total amount of HDL as depicted in the figure and increased HDL particle size (Baseline: 9.0 nm (SD 9.0) difference: 0.11 nm (0.1; 0.2), P<0.001). No changes were seen following AIT. No significant betweengroup differences were seen. Conclusion: One year of LED+AIT increased the proportion of lipoprotein constituted by HDL, induced a shift in the HDL distribution and increased HDL particle size while no change was seen following AIT alone; however, no significant between group differences were seen.