Abstract
BACKGROUND: We used single-marker and novel gene-based methods to examine the associations of endothelial system genes with blood pressure (BP) changes and hypertension in a longitudinal family study. METHODS: The Genetic Epidemiology Network of Salt Sensitivity follow-up study was conducted among 1,768 Chinese participants from 633 families. Nine BP measurements were obtained at baseline and at 2 follow-up visits using a random-zero sphygmomanometer. Mixed-effect models were used to assess the additive associations of 206 single-nucleotide polymorphisms (SNPs) in 15 endothelial system genes with longitudinal BP changes and hypertension incidence. Gene-based analyses were conducted using the truncated product method. The Bonferroni method was used to adjust for multiple testing in all analyses. RESULTS: Among those free from hypertension at baseline, 512 (32.1%) developed hypertension during the average 7.2 years of follow-up. In single-marker analyses, each copy of the minor alleles of correlated SELE markers rs4656704, rs6427212, and rs5368 were associated with increased risk of developing hypertension (P for trend = 1.48 × 10(-4), 6.69 × 10(-5), and 7.64 × 10(-5), respectively). In addition, the minor allele of SELE marker rs3917436 was associated with smaller diastolic BP (DBP) increases over time. Results of gene-based analyses confirmed associations of the SELE gene with the longitudinal BP phenotypes (P values < 1.00 × 10(-6) for DBP change and hypertension incidence). Furthermore, the DDAH1 and COL18A1 genes were associated with systolic BP change (P < 1.00 × 10(-6) and P = 4.00 × 10(-6), respectively), while EDNRA was associated with hypertension incidence (P = 2.39 × 10(-4)). CONCLUSIONS: The current study provides strong evidence of a role of endothelial system genes in BP progression and hypertension incidence.