A Study on Polymorphisms of Elastin Gene in Chinese Han Patients With Isolated Systolic Hypertension

BACKGROUND: Elastin (ELN) is mainly located in the internal elastic lamina of large arteries. Degradation of ELN is expected to induce large vessel stiffness, which could lead to elderly systolic hypertension. Recent studies have shown that polymorphism of ELN is associated with stiffness of elastic arteries and elevated blood pressure; however, there are no further studies on isolated systolic hypertension (ISH). METHODS: We identified the genotype of the ELN gene in 358 patients with ISH, 413 essential hypertension (EH) patients with elevated diastolic blood pressure (DBP), and 244 age-matched normotensive (NT) controls for five single-nucleotide polymorphisms (SNPs) and detected the brachial-ankle pulse wave velocity (baPWV), C-reactive protein (CRP), and intima-media thickness (IMT) for these patients. RESULTS: ISH was statistically significant in association with SNP rs34208922 (A allele frequency was 0.068 in ISH patients, 0.036 in EH patients, and 0.014 in NT controls; P < 0.001, P(corr) < 0.005) and possibly with SNP rs2071307 (A allele frequency was 0.103 in ISH patients, 0.079 in EH patients, and 0.047 in NT controls; P = 0.002, P(corr) = 0.01), however, the A allele frequency was not different between ISH patients and EH patients. In addition, baPWV and CRP were significantly associated with SNP rs34208922 and rs2071307. The other three SNPs were not significantly associated with ISH, baPWV, CRP, or IMT. Haplotypes of TGGTA and TGAT- were also significantly associated with ISH (P = 0.0001, P(corr) = 0.0021; P = 0.0023, P(corr) = 0.0483). CONCLUSIONS: Variants within the ELN gene are associated with increased risk of ISH and aortic stiffness in the Chinese Han population.