Objective: To investigate the effects of low density lipoprotein receptor gene (LDLR) Pvu II polymorphism on serum lipid ratios and their responses to high-carbohydrate/low-fat (HC/LF) diet in healthy youth.
Methods: After a regular diet for 7 days of wash-out, 56 health youth ((22.89 +/- 1.80) years old)] were given LF/HC diet for 6 days. The regular diet contained 54% carbohydrate, 15% protein, and 31% fat of the total energy. The LF/HC diet contained 70% carbohydrate, 15% proteine and 15% fat of the total energy. The serum lipids were measured on the 1st, the 8th and the 14th days. The ratios of TG/HDL-C, log (TG/HDL-C), TC/HDL-C, and LDL-C/HDL-C were calculated. The polymorphism of LDLR was detected by PCR-RFLP method and its relationship with serum lipid ratios was analyzed.
Results: No significant difference was found of the lipid ratios at baseline in subjects with different genotypes in both genders. Before or after HC/LF diet, no significant difference was found of the lipid ratios between the subjects with different genotypes in the whole study population or in males and females separately. Compared with those of before HC/LF diet, all the subjects experienced significant decrease of TC/HDL-C and LDL-C/HDL-C (P < 0.05). When gender was taken into account, significant increases of TG/HDL-C and log(TG/HDL-C) were found only in females (P < 0.05). All the subjects experienced significant decrease of TC/HDL-C regardless of gender and genotype (P < 0.05). As for LDL-C/HDL-C, significant decrease was found only in males with P1P1 and female subjects (P < 0.05).
Conclusion: Polymorphism of LDLR Pvu II may influence the response of LDL-C/HDL-C to HC/LF diet in males.