Uric Acid and Prevalence of Hypertension in a General Population of Japanese: ISSA-CKD Study

Background There is uncertainty surrounding the causal relationship between serum uric acid and hypertension. The aim was to investigate the association between serum uric acid and prevalence of hypertension in a general population of Japanese. Methods This was a population-based cross-sectional study using health check-up data of the residents of the Iki City, Nagasaki Prefecture, Japan. A total of 7,484 participants aged 30 years or older were included in this study. Serum uric acid was classified into four groups: group 1 (< 357 µmol/L (< 6 mg/dL)), group 2 (357 - 415 µmol/L (6 - 6.9 mg/dL)), group 3 (416 - 475 µmol/L (7 - 7.9 mg/dL)) and group 4 (≥ 476 µmol/L (≥ 8 mg/dL)). Hypertension was defined as blood pressure (BP) levels of ≥ 140/90 mm Hg or use of BP lowering medications. Results Hypertension was observed among 3,467 participants (prevalence 46.3%). The prevalence of hypertension increased with elevation of serum uric acid levels: 42.8% in group 1, 55.0% in group 2, 57.6% in group 3 and 59.8% in group 4 (P < 0.001 for trend). This association was significant even after adjustment for other risk factors including age, sex, current smoking, current alcohol intake, obesity, diabetes, dyslipidemia, estimated glomerular filtration rate and proteinuria: odds ratios (95% confidence intervals) were 1.50 (1.28 - 1.77) for group 2, 1.58 (1.25 - 1.99) for group 3 and 1.89 (1.36 - 2.64) for group 4 compared with the reference group of group 1 (P < 0.001 for trend). Conclusions Serum uric acid was clearly associated with prevalence of hypertension in a general population of Japanese.