SIGNIFICANT CHANGES IN THE LIPID-LIPOPROTEIN STATUS OF PREMENOPAUSAL MORBIDLY OBESE FEMALES FOLLOWING GASTRIC BYPASS-SURGERY

The morbidly obese premenopausal female may be more dyslipoproteinemic and at greater risk for developing coronary heart disease than her le an or less seriously obese counterparts. The purpose of the present st udy was to examine the effects of weight loss with Roux-en-Y gastric b ypass surgery on the lipid-lipoprotein status of morbidly obese, preme nopausal females. Anthropometrics and blood samples for lipid-lipoprot ein analyses were obtained before surgery and 6 - 12 months postoperat ively. Following surgery, patients lost 30% of their initial body weig ht, along with a 40% decline (p < 0.01) in total triglyceride and a 20 % decrease (p < 0.01) in total cholesterol. Levels of cholesterol in t he high density lipoprotein (HDL) fraction were unaffected by weight l oss, but there was a significant (p < 0.05) increase in the proportion of HDL in its more buoyant and anti-atherogenic form, i.e. HDL-L. The apolipoprotein B-containing lipoproteins, very low density lipoprotei n (VLDL), intermediate density lipoprotein (IDL), and low density lipo protein (LDL), were reduced up to 70% following surgery. There were no significant changes in VLDL or IDL particle composition, i.e. cholest erol/triglyceride, cholesterol. protein, but there was a significant ( p < 0.01) increase in the ratio of cholesterol/apolipoprotein a in LDL , suggesting a shift from the small, dense atherogenic LDL to a larger , less atherogenic particle. We conclude that weight loss following ga stric bypass surgery markedly improves the lipid-lipoprotein status of morbidly obese premenopausal females and, thereby, significantly redu ces the risk of coronary disease.