Genetic polymorphism of S447X lipoprotein lipase (LPL) and the susceptibility to hypertension

Introduction: Lipoprotein lipase (LPL) is a rate-limiting enzyme responsible for the hydrolysis of triacylglycerol-rich lipoproteins releasing monoglycerides and free fatty acids, which are taken up by skeletal muscles and adipose tissue. S447X polymorphism in exon 9 of LPL gene on chromosome 8 p22 results from replacement of serine amino acid with a stop codon creating a restriction site. It has been hypothesized that the more common SS genotype is associated with a lower LPL activity compared with the infrequent SX/XX genotype. Objectives: To investigate the effect of genetic polymorphism of LPL S447X in blood pressure and its atherogenic phenotype. Materials and Methods: S447X variant genotype of LPL were determined by polymerase reaction (PCR) restriction fragment length polymorphism assay in 50 hypertensive patients and 50 normotensive as a control group. Anthropometric measurements and serum lipoproteins were also determined in both groups. Results: The frequency of (SS) genotype was 78% in hypertensive group compared to 66% in normotensive group. Carrier of (SS) genotype were at higher risk of developing hypertension (OR, 1.8; 95% CI, 0.8-4.4) when compared with carrier of other genotypes. Furthermore, they showed atherogenic phenotype manifested by central obesity and dyslipidemia. Odds ratios were 1.8 and 2.6, respectively. Conclusion: It was found that carriers of (SS) genotype were at high risk of developing hypertension.