Interrelationships between body mass and lipid and lipoprotein triglycerides and cholesterol in obese women.

In 72 obese women body mass index positively correlated with age and both showed multiple correlations with serum lipids and lipoprotein lipids. After adjustment for age (partial correlation procedure), body mass index resulted to be positively correlated with serum triglycerides, VLDL lipids, HDL-triglycerides and negatively correlated with HDL-cholesterol. The decrease in HDL-cholesterol concentration along with the increase in body weight was due to the reduction of cholesterol in HDL2 subfraction, while HDL3-cholesterol did not show any significant correlation with body mass index. The negative correlation between HDL2-cholesterol and body mass index was independent of other lipoprotein variables and in particular of VLDL lipid levels that were, as expected, inversely related to HDL2-cholesterol. HDL2-cholesterol is believed to be a strong protective factor against atherosclerosis, while doubts exist on the meaning of VLDL lipids as risk factors. Thus, the decrease in HDL2-cholesterol concentration, rather than the increase in VLDL lipids, might give a rational basis to the high incidence rate of vascular disease in obese subjects.

Changes in serum lipoprotein pattern following bezafibrate. Differential effects in type IIa and in type IIb hyperlipoproteinemic patients.

Sixteen type IIb and 26 type IIa hyperlipoproteinemic patients were treated with bezafibrate 200 mg t.i.d. After 1 month VLDL-TG decreased by 54% in type IIb and by 43% in type IIa; LDL-C decreased by 13% in type IIb and by 23% in type IIa patients. HDL3-C rose in both group of patients, while HDL2-C significantly increased (52%) only in patients with phenotype IIb. The change in LDL-C and in HDL2-C concentrations resulted to be related to the pretreatment VLDL lipid concentration and to its change during the treatment. Twenty patients were treated with bezafibrate for 4 months. On the average, the changes in lipoprotein lipid concentration attained at the end of the first month of therapy remained substantially constant in the following 3 months.

Serum lipoprotein subfractions before and during low-calorie diet in obese women.

Twenty-five obese women were put on low-calorie diet for one month. The mean weight loss was 2.7 kg and was accompanied by a 9% decrease of LDL-cholesterol. LDL-apolipoprotein B (in 13 subjects) showed a 16% fall and LDL-triglyceride levels did not change. The results suggest both a decrease of LDL concentration and a relative increase of triglyceride-rich particles in the density range of 1.006-1.063. HDL2-cholesterol showed a 17% decrease and HDL3-cholesterol a 16% increase. Total and lipoprotein triglycerides were not modified. The changes of lipoprotein pattern suggest a sluggish VLDL catabolism by lipoprotein lipase. In 10 women followed for 6 months the decrease of LDL-cholesterol seen after one month of diet was no more present at the 6th month, while the decrease of HDL2-cholesterol and the increase of HDL3-cholesterol were still evident. At the end of the 6th month a slight but significant decrease of total and VLDL-triglycerides also occurred.

Changes in the serum lipoprotein pattern induced by two low-fat diets with a different vegetable content in hypercholesterolemic patients.

Thirty-two hypercholesterolemic outpatients were treated by a conventional low-fat diet (carbohydrate 56%; fat 25%; vegetable proteins 7%; animal proteins 12% of energy; P/S ratio 1.0). After 1 month T-C decreased by 11%, VLDL-C by 32%, LDL-C by 8%, HDLt-C by 10% and HDL2-C by 11%. Thirty-two comparable patients were treated by a different low-fat diet which provided 69% of energy as carbohydrate, 19% as fat, 7% as vegetable proteins and 5% as animal proteins; P/S ratio was 1.3. After 1 month T-C decreased by 9% and LDL-C by 12%. VLDL-C, HDL2-C and HDL3-C did not change significantly. A cross-over study on 24 patients confirmed that both diets have lowering effects on T-C and LDL-C levels, but only the conventional low-fat diet decreases VLDL-C and HDL2-C.