Hyperuricemia is associated with all-cause and cardiovascular mortality. However, the threshold value of serum uric acid levels for increased risk of mortality has not been determined. This large-scale cohort study used a nationwide database of 500,511 Japanese subjects (40–74 years) who participated in the annual health checkup and were followed up for 7 years. The association of serum uric acid levels at baseline with cardiovascular and all-cause mortality was examined. The Cox proportional hazard model analysis with adjustment for possible confounders revealed that the all-cause and cardiovascular mortality showed a J-shaped association with serum uric acid levels at baseline in both men and women. A significant increase in the hazard ratio for all-cause mortality was noted with serum uric acid levels ≥ 7 mg/dL in men and ≥ 5 mg/dL in women. A similar trend was observed for cardiovascular mortality. This study disclosed that even a slight increase in serum uric acid levels was an independent risk factor for all-cause and cardiovascular mortality in both men and women in a community-based population. Moreover, the threshold values of uric acid for mortality might be different for men and women.

Hypertension and proteinuria are risk factors for adverse renal outcomes in patients with chronic kidney disease. This study investigated the associations of blood pressure and proteinuria on renal function in a community-based population. We analyzed data from a nationwide database of 141,514 subjects who participated in the annual “Specific Health Check and Guidance in Japan” checkup in 2008 and 2010. The study subjects were aged between 29 and 74 years, and the cohort comprised 40% men. We examined relationships between blood pressure levels, proteinuria at baseline, and the 2-year change in the estimated glomerular filtration rate (eGFR), which was determined using the Japanese equation. After adjusting for possible confounders, the change in the eGFR was inversely correlated with systolic blood pressure (SBP), but not diastolic blood pressure (DBP), at baseline, irrespective of the presence of proteinuria. Compared with the lowest SBP sixtile (≤118mm Hg), eGFRs declined significantly at SBPs ≥ 134mm Hg in subjects with proteinuria, while eGFRs declined significantly at SBPs ≥ 141mm Hg in those without proteinuria. At the same SBPs, renal function decline was faster and the risk for incident renal insufficiency was higher in subjects with proteinuria compared with those without proteinuria. This study showed that a difference in SBP, but not DBP, is independently associated with a rapid eGFR decline in the general Japanese population, and that the association of SBP on the decline of renal function was greater in subjects with proteinuria compared with those without proteinuria.