Validation of age- and sex-dependent association of uric acid and incident hypertension in rural areas

Background A previous study based on urban areas suggested the age- and sex-dependent association of uric acid (UA) and incident hypertension. We aimed to investigate whether this association is valid even in rural areas with different lifestyle. Methods Data from the cardiovascular disease association study, a prospective cohort study based on rural residents, was analyzed. A total of 4,592 subjects (mean age, 60.1 [+ or -] 9.5 years; men, 37.7%) without hypertension were included. We first investigated whether UA was a risk factor for incident hypertension using Cox regression, and then compared the relative risk by stratification according to age and sex. Results During the follow-up period (mean, 2.0 years), 579 subjects (12.6%) were newly diagnosed with hypertension. The risk factors for incident hypertension were age (Hazard ratios [HR] for [greater than or equal to] 65, 1.26), systolic blood pressure (HR per 1 mmHg increase, 1.07), and serum UA concentration (HR per 1 mmHg increase, 1.10). The risk of UA-related incident hypertension was higher in the non-elderly than in the elderly for both men and women (HR, 1.74 for non-elderly men; 1.88 for non-elderly women; 1.66 for elderly men; 1.10 for elderly women). Even after adjusting for multiple confounders, the risk of UA-related incident hypertension was significantly higher in non-elderly women (HR, 1.59; P < 0.05). Conclusions Age- and sex-dependent association of UA with incident hypertension suggested in cohort study based on urban areas was consistently found in rural areas as well. In particular, non-elderly women were at a higher risk for UA-related incident hypertension. Keywords: Uric acid, Hyperuricemia, Hypertension