Objective: To investigate the AvaII polymorphism of low density lipoprotein receptor gene in both health and essential hypertension populations, and to evaluate the association of AvaII polymorphism with level of blood lipid.
Methods: Using polymerase chain reaction (PCR), AvaII polymorphism was studied in 109 health individuals and 319 patients with essential hypertension.
Results: There were three kinds of genotype: (+/+), (+/-), (-/-). The frequencies of the three genotypes were shown as follows: (+/+) 0.9%, (+/-) 27.5%, (-/-) 71.6% in health population and (+/+) 1.2%, (+/-) 33.9%, (-/-) 64.9% in essential hypertension population, respectively. The frequencies of the two alleles were shown as follows: (+) 14.7%, (-) 85.3% in health population, (+) 18.2%, (-) 81.8% in essential hypertension population and (+) 17.3%, (-) 82.7% in the community, respectively. In male essential hypertension cases, the genotypes were associated with serum TC and LDL-C level in the following order: (-/-) < (+/-) (P < 0.05). In women and healthy population, there was a similar trend but not statistically significant (P > 0.05).
Conclusions: A significant association was found between the common variation of LDL-R gene and serum TC and LDL-C levels. (+) Allele was associated with elevated level of serum TC and LDL-C, but (-) allele was associated with a low level of serum TC and LDL-C. The frequencies of (-) allele in both group were related to serum low level TC while LDL-C was much higher than that reported in the western countries. These data indicated that genetic factors which resistant to hypercholesterolemia in Chinese people were different from those findings in West while might be one of the reasons to explain why that serum TC level in Chinese was lower than people in the western countries.