Lipoprotein metabolism following gastroplasty in obese women.
In order to elucidate the long-term alterations in cholesterol transport and esterification as a part of the changes in the carbohydrate and lipoprotein metabolism subsequent to calorific restriction, 15 obese women were investigated before and after treatment with vertical banded gastroplasty. Insulin resistance and production, lipid levels in plasma, lipoproteins and the lecithin: cholesterol acyl transferase (LCAT) rate were assessed. There was a 60% decrease in mean calorific intake six months after surgery. A slight hyperglycaemia was almost normalized concomitant with a reduction of serum insulin and C-peptide after 1 year. The very low density lipoprotein (VLDL) level was unchanged. The high density lipoprotein (HDL) levels tended to rise after 1 year, when there was a significant increase of the HDL-2 subfraction. The lipid levels in the lipoprotein fractions showed a rise in mean HDL-2 cholesterol. Both the molar and fractional rates of LCAT were decreased. These results suggest that long-term calorific restriction reduces insulin resistance and production, and lowers VLDL levels and VLDL and cholesterol synthesis. However, the low density lipoprotein cholesterol levels are unchanged, probably because of a decrease in the previously elevated fractional cholesterol removal.