LDLR gene polymorphism (rs688) affects susceptibility to cardiovascular disease in end-stage kidney disease patients

The low-density lipoprotein receptor (LDLR) plays a significant role in maintaining the cellular cholesterol homeostasis. Mutations in the LDLR gene can lead to a significant rise in plasma LDL levels that may result in an increased risk of atherosclerosis and coronary heart disease. The purpose of this study was to assess the potential association of the LDLR rs688 polymorphism with cardiovascular disease (CVD) in patients with end-stage kidney disease (ESKD) undergoing hemodialysis.

In this case-control study the polymorphism was genotyped by the allele specific PCR method in 800 patients with ESKD and 500 healthy controls. The genotype and allele distribution was compared in subgroups of patients with CVD (552) versus those without CVD (248).

A significant difference was observed in genotype distribution among ESKD patients and healthy controls. The frequencies of the T allele and TT genotype in ESKD group were significantly higher, with OR (95% CI) 2.2 (1.87-2.6), p <  0.0001 and 5.84 (3.94-8.65), p <  0.0001, respectively. In the he ESKD cohort the distribution of the rs688 was compared between CVD+ and CVD- subgroups. A strong association of the polymorphism with the CVD risk was observed in this analysis. The frequencies of the T allele and TT genotype were significantly higher in CVD+ subgroup, with OR (95% CI) 3.4 (2.71-4.26), p <  0.0001 and 13.2 (7.87-22.09), p <  0.0001, respectively. A multivariate logistic regression analysis was performed to estimate the association between rs688 T variant and risk of CVD. After adjustment for age, sex, BMI, hypertension and diabetes, both CT and TT genotypes were associated with an increased risk of developing CVD in the dominant, recessive and codominant models of inheritance. No significant differences in serum LDL cholesterol levels were found when compared between genotypes.

The present study is the first to demonstrate the association of the LDLR gene polymorphism with increased susceptibility to cardiovascular disease in ESKD patients. This finding needs further investigation to confirm that LDLR rs688 might be a novel genetic risk factor with some prognostic capacity for CVD in ESKD patients.