Effect of dietary treatment on the lipid, lipoprotein and fatty acid compositions in type IV familial hypertriglyceridemia.

The effects of a 2-month dietary treatment (1,625 +/- 177 kcal, 40 +/- 2.3% carbohydrate, 35 +/- 3.7% fat, 25 +/- 2% protein, polyunsaturated/saturated fat ratio = 1.02 +/- 0.06) on the overall composition of serum lipids, lipoproteins and the fatty acid composition of cholesterol esters and phospholipids in very low (VLDL), intermediate (IDL), low (LDL) and high (HDL) density lipoprotein in 5 patients with primary familial hypertriglyceridemia type IV were assessed. The data were compared with those for 9 normolipidemic subjects. Treatment decreased serum triglycerides (-52%) and total cholesterol (-12%) due to decrease in free cholesterol (-30%). It produced a significant decrease in all the constituents of VLDL (-58%), but the VLDL remained significantly higher after treatment than those of control subjects. The diet caused a decrease in triglycerides (-16%, -29% and -33%, respectively), and an increase in cholesterol in IDL, LDL and HDL. The IDL level in the treated patients remained significantly higher than in the controls. The LDL cholesterol/HDL cholesterol ratio was unchanged after treatment. The fatty acid compositions of the patients before treatment and the controls were not significantly different. The diet caused a decrease in palmitoleic and oleic acids in the cholesterol ester fraction and an increase in linoleic acid, but this was significant only in VLDL and HDL. The diet decreased the eicosapentaenoic acid but the drop was only significant in IDL and LDL. There was also a decrease in linolenic acid, only significant in IDL. The diet induced only minor changes in the phospholipid fractions. We concluded that a single nutritional regimen can effectively decrease the serum lipids and normalize the lipoprotein composition of type IV hypertriglyceridemic patients.