ABSTRACT
<p><b>OBJECTIVE</b>To analyze the distribution of matrix metalloproteinase-3 (MMP-3) genotype and its association with the blood pressure profiles in Guangzhou rural population.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>