Genome-wide linkage and regional association study of blood pressure response to the cold pressor test in han chinese the genetic epidemiology network of salt sensitivity study

Background: Blood pressure (BP) response to cold pressor test (CPT) is associated with increased risk of cardiovascular disease. We performed a genome-wide linkage scan and regional association analysis to identify genetic determinants of BP response to CPT. Methods and Results: A total of 1961 Chinese participants completed the CPT. Multipoint quantitative trait linkage analysis was performed, followed by single-marker and gene-based analyses of variants in promising linkage regions (logarithm of odds ≥2). A suggestive linkage signal was identified for systolic BP response to CPT at 20p13 to 20p12.3, with a maximum multipoint logarithm of odds score of 2.37. On the basis of regional association analysis with 1351 single nucleotide polymorphisms in the linkage region, we found that marker rs2326373 at 20p13 was significantly associated with mean arterial pressure responses to CPT (P=8.8×10_-6) after false discovery rate adjustment for multiple comparisons. A similar trend was also observed for systolic BP response (P=0.03) and diastolic BP response (P=4.6×10_-5). Results of gene-based analyses showed that variants in genes MCM8 and SLC23A2 were associated with systolic BP response to CPT (P=4.0×10_-5 and 2.7×10_-4, respectively), and variants in genes MCM8 and STK35 were associated with mean arterial pressure response to CPT (P=1.5×10_-5 and 5.0×10_-5, respectively). Conclusions: Within a suggestive linkage region on chromosome 20, we identified a novel variant associated with BP responses to CPT. We also found gene-based associations of MCM8, SLC23A2, and STK35 in this region. Additional work is warranted to confirm these findings..