Effect of dietary modification by calorie restriction on cholesterol levels in lipoprotein(a) and other lipoprotein classes.

Background Dietary habits are associated with obesity which is a risk factor for coronary heart disease. The objective is to estimate the change of lipoprotein(a) and other lipoprotein classes by calorie restriction with obesity index and Framingham risk score. Methods Sixty females (56 ± 9 years) were recruited. Their caloric intakes were reduced during the six-month period, and the calorie from fat was not more than 30%. Lipoprotein profiles were estimated at baseline and after the six-month period of calorie restriction. Cholesterol levels in six lipoprotein classes (HDL, LDL, IDL, VLDL, chylomicron and lipoprotein(a)) were analysed by anion-exchange liquid chromatography. The other tests were analysed by general methods. Additionally, Framingham risk score for predicting 10-year coronary heart disease risk was calculated. Results Body mass index, waist circumference, insulin resistance, Framingham risk score, total cholesterol, LDL-cholesterol and IDL-cholesterol were significantly decreased by the calorie restriction, and the protein and cholesterol levels of lipoprotein(a) were significantly increased. The change of body mass index was significantly correlated with those of TC, VLDL-cholesterol and chylomicron-cholesterol, and that of waist circumference was significantly correlated with that of chylomicron-cholesterol. The change of Framingham risk score was significantly correlated with the change of IDL-C. Conclusion Obesity indexes and Framingham risk score were reduced by the dietary modification. Lipoprotein profile was improved with the reduction of obesity indexes, but lipoprotein(a) was increased. The changes of obesity indexes and Framingham risk score were related with those of triglyceride-rich lipoproteins, e.g. IDL, VLDL and CM.