Effect of weight loss on HDL-apoA-II kinetics in the metabolic syndrome

Abstract

Reduced HDL (high-density lipoprotein) concentration in the MetS (metabolic syndrome) is associated with increased risk of cardiovascular disease and is related to defects in HDL-apoA-II (apolipoprotein A-II) kinetics. Dietary restriction is the most commonly used weight loss strategy. In the present study, we examined the effect of weight loss on HDL-apoA-II kinetics in men with the MetS at the start and end of a 16-week intervention trial of a hypocaloric low-fat diet (n = 20) compared with a weight maintenance diet (n = 15), using a stable isotope technique and compartmental modelling. The low-fat diet achieved a significant reduction (P < 0.01) in BMI (body mass index), abdominal fat compartments and HOMA (homoeostasis model assessment) score compared with weight maintenance. Weight loss also significantly (P < 0.05) decreased both the production rate (-23 %) and FCR (fractional catabolic rate) (-12 %) of HDL-apoA-II, accounting for a net decrease in apoA-II concentration (-9%). Reductions in the HDL-apoA-II production rate were significantly associated with changes in body weight (r = 0.683, P < 0.01), plasma triacylglycerols (triglycerides) (r = 0.607, P < 0.01) and, to a lesser extent, plasma insulin (r = 0.440, P = 0.059) and HOMA-IR (HOMA of insulin resistance) (r = 0.425, P = 0.069). Changes in the apoA-II FCR were also significantly associated with reductions in visceral adipose tissuemass (r = 0.561, P = 0.010). In conclusion, in obese men with the MetS, short-term weight loss with a low-fat low-caloric diet lowers plasma apoA-II concentrations by decreasing both the production and catabolism of HDL-apoA-II. The cardiometabolic significance of this effect on HDL metabolism remains to be investigated further.