ارزیابی تأثیر نوع رژیم غذایی گامِ 2 کاهش کلسترول در نوجوانان مبتلا به اختلالات چربی خون بر قطر ذرات لیپوپروتئین ها

Background: The NCEP step II diet produced a desirable lipoprotein response in hypercholesterolemia. A relation between plasma concentrations of small dense LDL and cardiovascular risk factors has also been mentioned in children. This study was conducted to determine the effects of the National Cholesterol Education Program (NCEP) step 2 diets on the low density and high density lipoprotein particle size in dyslipidemic adolescents.Methods: Forty- four dyslipidemic adolescents, aged 10-18 years, participated in this case-control study. The control group was not given a diet prescription and was simply instructed to “eat as usual”. Their eating patterns reflected the consumption of macronutrients, fruit, vegetables and dairy products, typical of what many Tehranian eat. NCEP step 2 diets was a diet with 30% of calories as total fat, less than 7% saturated fat, less than 200 mg cholesterol, less than 15% of calories as monounsaturated fat and less than 10% as polyunsaturated fat per day. Lipoprotein particle size was the major outcome variables, which was measured after 3 months of intervention. Lipoprotein particle size was estimated by nondenaturing polyacrylamide gradient gel electrophoresis using Krauss and Burke methodtion. Results: The mean body mass index was 26.3±4.2 kg/m2. Baseline characteristics of these adolescents did not differ significantly across the NCEP step 2 and control diet groups. The NCEP diet resulted in higher reduction in total cholesterol (-13±4 vs –2±0.3 mg/dl, p<0.001), LDL (-9±2 vs 3±0.6 mg/dl, p<0.01) and higher increase in size of the LDL (1.7±0.4 vs 0.1±0.4 mg/dl, p<0.001). HDL particle size did not change significantly. The prevalence of hypercholesterolemia decreased significantly (p<0.05) in NCEP step 2 group (68% in NCEP step 2 vs 100% in the control group) after 3 months.Conclusion: NCEP step 2 diet not only reduces the serum LDL concentration of hypercholesterolemic adolescents but also has a favorable effect on the LDL particle size distribution. The related mechanism needs to be studied in future experimental designs.