Abstract: Objective To analyze the distribution of matrix metalloproteinase-3 (MMP-3) genotype and its association with the
blood pressure profiles in Guangzhou rural population. Methods This study was conducted among 680 rural residents aged
40-70 years (including 314 men and 366 women) from 3 villages in an rural area of Guangzhou. The blood pressures of the
subjects were measured and blood samples were collected for genotype analysis using polymerase chain reaction and direct
sequencing of the MMP-3 gene promoter region to detect the 5 adenines (5A)/6 adenines (6A) polymorphisms. Results The
frequencies of MMP-3 genotypes 6A/6A, 5A/5A, and 5A/6A were 82.6%, 1.8% and 15.6% among these residents, respectively.
The distribution of MMP-3 genotypes and allele frequencies showed no significant gender- or age-related variations. The men
with different genotypes (6A/6A vs 5A/6A+5A/5A) did not show significant differences in blood pressure levels, whereas the
women with 5A/6A+5A/5A genotypes had higher systolic and diastolic blood pressures than those with a 6A/6A genotype. The
allele 5A was highly frequent in the hypertensive residents as compared with the normotensive residents. Conclusion The 6A
homozygote is the predominant genotype of MMP-3 in Guangzhou rural population, which has a significantly lower
proportion of 5A homozygote than the Western populations. The 5A allele is associated with a high risk of hypertension
especially in women and may affect both systolic and diastolic blood pressures.