Synergistic influence of age and serum uric acid on blood pressure among community-dwelling Japanese women.

Serum uric acid (SUA) levels are strongly correlated with aging, gender, renal function, obesity, and metabolic abnormality; however, whether SUA has a causative role in elevated blood pressure (BP) is still a matter of debate. From a single community, we recruited 1177 eligible women (mean age, 61±13 years) during their annual health examination. All subjects were divided into two groups according to their age (participants aged ≥55 years and those aged <55 years). We investigated whether age and SUA are synergistically associated with BP, independent of confounding factors. Of these subjects, SUA significantly correlated with both systolic BP (SBP; r=0.236, P<0.001) and diastolic BP (DBP; r=0.263, P<0.001) in female participants aged <55 years but not in those aged ≥55 years. The interaction between age and SUA on BP as well as age and body mass index, triglycerides, high-density lipoprotein cholesterol, fasting plasma glucose, prevalence of antidiabetic medication and SUA was a significant and independent determinant of both SBP (β=-0.106, P=0.011) and DBP (β=-0.070, P=0.003). In participants aged <55 years, the multivariate-adjusted odds ratio (95% confidence interval) for hypertension was 3.03 (1.13-8.11) for the highest tertile (4.8-10.8 mg dl(-1)) of SUA compared with the lowest tertile (0.7-3.8 mg dl(-1)) but was not significant in those aged ≥55 years. These results suggested that age and SUA have a synergistic effect on BP status in community-dwelling women, independent of conventional cardiovascular risk factors.