Association of blood pressure and hyperuricemia with proteinuria and reduced renal function in the general population

This study aimed to investigate the effect of hyperuricemia (HU) on the association of systolic blood pressure (SBP) with the prevalence of proteinuria and low estimated glomerular filtration rate (eGFR) in the general population. This cross-sectional study enrolled 24,728 Japanese individuals (11,137 men and 13,591 women) who underwent health checkups in 2010. The prevalence of proteinuria and low eGFR (< 60 mL/min/1.73 m²) among participants classified according to serum uric acid levels and SBP was compared. HU was defined as serum uric acid levels higher than the 75th percentile in male and female participants (> 7.2 and > 5.4 mg/dL, respectively). The odds ratio (OR) for proteinuria increased with elevated SBP. This trend was significantly evident in participants with HU. Moreover, there was an interactive effect of SBP and HU on the prevalence of proteinuria in the male (P_{for interaction} = 0.04) and female (P_{for interaction} = 0.04) participants. Next, we evaluated the OR for low eGFR (< 60 mL/min/1.73 m²) with and without proteinuria based on the presence of HU. The multivariate analysis revealed that the OR for low eGFR with proteinuria increased with elevated SBP, but that for low eGFR without proteinuria decreased. These trends of OR tended to be prevalent among those with HU. The association between SBP and the prevalence of proteinuria was more pronounced in participants with HU. However, the association between SBP and decreased renal function with and without proteinuria might be different regardless of HU.