Association of adrenomedullin gene polymorphisms and blood pressure in a Chinese population.

Genetic factors may determine an individual's blood pressure (BP) level and risk for hypertension. This study aimed to examine the associations between genetic variants of the adrenomedullin (ADM) gene and essential hypertension, as well as BP levels, in a Chinese Han population. In this study, 2410 hypertensive patients and 2346 normal controls were recruited. Three tagging single-nucleotide polymorphisms (SNPs) based on the HapMap CHB data were selected and genotyped. No significant associations between the three SNPs of the ADM gene and hypertension status were observed. However, SNP rs4399321 was found to be associated with BP levels among the controls. GG homozygotes for this SNP had higher systolic BP (SBP) levels than carriers of the A allele (P=0.002). Particularly in non-drinkers, GG homozygotes had significantly higher SBP (116.9±0.9 vs. 113.7±0.3 mm Hg, P=0.001) and diastolic (74.0±0.7 vs. 72.6±0.2 mm Hg, P=0.046) BP levels than carriers of the A allele. Neither rs4910118 nor rs7944706 was associated with BP levels in the controls either before or after being stratified by drinking status. The results of this study showed that genetic variations in the ADM gene were not associated with the risk of hypertension in a Chinese population. However, the genotype at common variation rs4399321 may influence the BP level in normotensive subjects, especially among non-drinkers. In addition, replications in other populations and further functional studies are required to confirm and interpret the association of ADM with BP.