Effects of weight loss and phenotype traits on changes in body composition and cholesterol metabolism in overweight individuals
Global obesity is linked to chronic diseases including hypercholesterolemia, a cardiovascular disease risk factor, thus weight reduction in obesity is a key priority for combatting obesity. The cholesterol transporters ABCG5, ABCG8 and NPC1L1 mediate cholesterol trafficking across the intestinal wall, thus are important in regulating cholesterol metabolism and circulating levels. The objective of this study was to examine if single nucleotide polymorphisms (SNP) of cholesterol transporters ABCG5, ABCG8 and NPC1L1 are associated with changes in cholesterol synthesis and absorption and lipid parameters (LP) subsequent to weight loss (WtL) in overweight individuals. Eighty-nine individuals from two WtL trials (Trial A (n = 54) and Trial B (n = 35)) completed a 20-wk WtL period. After 10% WtL, lipid parameters excluding LDL-C were improved in Trial A, while all lipid parameters were ameliorated after 12% of WtL when Trial A and B were combined. Post-WtL, cholesterol synthesis (CS) was reduced; however, cholesterol absorption was not changed in either Trial A or the combined trials. Polymorphisms in ABCG8 V632A were associated with changes in TC and TG levels after WtL in both trial A and the combined data. SNPs in ABCG5 Q604E, ABCG8 T400K, were associated with changes in CS because of WtL in Trial A; however, the association is no longer seen in combined analysis. In conclusion, cardio-protective changes in LP due to weight loss were mediated by reductions in CS. Additionally, polymorphisms in ABCG8 were associated with amelioration in LP after WtL. Thus, the benefits in CVD risk subsequent to weight loss vary across individuals due to genetic factors associated with cholesterol trafficking.
weight loss, BMI, DEXA, body composition, fat mass, fat free mass, cholesterol absorption, cholesterol synthesis, HDL-C, LDL-C, total cholesterol, triglyceride, SNP, NPC1L1, ABCG5, ABCG8, diet, physical activity