angiotensinogen and Hyperuricemia

Both hyperuricaemia and activation of the intrarenal renin-angiotensin system (RAS) play an important role in the development of hypertension and renal damage. However, it has not been clear whether hyperuricaemia is associated with renal damage due to hypertension or intrarenal RAS activation, as well as their circadian rhythms.. We recruited 43 chronic kidney disease (CKD) patients who did not receive RAS blockers and antihyperuricaemic drugs, and investigated the relationship among serum uric acid (sUA) levels, the circadian rhythm of urinary angiotensinogen (U-AGT) excretion levels, and the levels of albuminuria (U-ACR) and proteinuria (U-P/Cr).. sUA levels were significantly associated with estimated glomerular filtration rate (eGFR) (P = 0.002), systolic blood pressure (SBP) (daytime, P = 0.031), and U-ACR (daytime, P = 0.006 and nighttime, P = 0.008) and U-P/Cr (daytime, P = 0.017 and nighttime, P = 0.013). However, there were no significant differences between sUA levels and SBP in nighttime and U-AGT excretion levels in both time periods. Multiple regression analyses for sUA levels were performed using age, sex, eGFR and each parameter (SBP, U-AGT/Cr, U-ACR or U-P/Cr). sUA levels were not associated with SBP or U-AGT/Cr in both time periods. sUA levels tended to correlate with U-P/Cr levels in nighttime, and were significantly associated with U-P/Cr in daytime (P = 0.026) and U-ACR in daytime (P = 0.017) and nighttime (P = 0.046). Moreover, no significant differences were found between sUA levels and night-to-day ratios of some parameters.. These data suggest that hyperuricaemia is associated with renal damage, independently of hypertension and intrarenal RAS activation, as well as their circadian rhythms.

Topics: Adult; Aged; Aged, 80 and over; Albuminuria; Angiotensinogen; Biomarkers; Blood Pressure; Circadian Rhythm; Female; Glomerular Filtration Rate; Humans; Hypertension; Hyperuricemia; Kidney; Kidney Diseases; Linear Models; Male; Middle Aged; Multivariate Analysis; Renin-Angiotensin System; Risk Factors; Time Factors; Uric Acid; Young Adult

Experimental and epidemiological studies have demonstrated that urinary angiotensinogen (AGT) is a novel biomarker for the intrarenal activity of the renin-angiotensin system in hypertension (HT). Several large-scale epidemiological studies have shown that an elevated serum uric acid (SUA) level is associated with HT. The aim of our study was to assess urinary AGT excretion and its correlation with SUA level, the lipid profile, and the body mass index (BMI) Z-score in hypertensive adolescents.. Participants were divided into two groups: (1) the group with confirmed HT consisting of 55 subjects with primary HT and (2) the reference (R) group consisting of 33 subjects with white-coat HT. A commercial enzyme-linked immunosorbent assay (ELISA) kit was used to determine urinary AGT concentration.. The urinary AGT/creatinine (cr.) ratio in subjects in the HT group was significantly higher than that in the reference group (p < 0.01) and showed a strong positive correlation with SUA (r = 0.47, p < 0.01). The relationship between the AGT/cr. ratio and SUA levels after controlling for age, gender and BMI Z-score continued to show a significant association.. The most obvious finding to emerge from this study is that in adolescents with primary HT, the increased urinary excretion of AGT correlated with hyperuricemia, although large, multicenter studies are needed to confirm this observation.

Topics: Adolescent; Angiotensin II; Angiotensinogen; Biomarkers; Body Mass Index; Chi-Square Distribution; Child; Creatinine; Cross-Sectional Studies; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hypertension; Hyperuricemia; Kidney; Linear Models; Lipids; Male; Multivariate Analysis; Predictive Value of Tests; Prospective Studies; Up-Regulation; Uric Acid