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Hyperuricaemia is associated with renal damage independently of hypertension and intrarenal renin‐angiotensin system activation, as well as their circadian rhythms
Author(s) -
Ohashi Naro,
Ishigaki Sayaka,
Isobe Shinsuke,
Tsuji Naoko,
Iwakura Takamasa,
Ono Masafumi,
Tsuji Takayuki,
Sakao Yukitoshi,
Kato Akihiko,
Yasuda Hideo
Publication year - 2015
Publication title -
nephrology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 61
eISSN - 1440-1797
pISSN - 1320-5358
DOI - 10.1111/nep.12504
Subject(s) - medicine , endocrinology , circadian rhythm , albuminuria , renal function , proteinuria , renin–angiotensin system , excretion , blood pressure , kidney disease , kidney , uric acid
Aim 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. Methods 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 / C r). Results 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 / C r (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 / C r, U ‐ ACR or U ‐ P / C r). sUA levels were not associated with SBP or U ‐ AGT / C r in both time periods. sUA levels tended to correlate with U ‐ P / C r levels in nighttime, and were significantly associated with U ‐ P / C r 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. Conclusion These data suggest that hyperuricaemia is associated with renal damage, independently of hypertension and intrarenal RAS activation, as well as their circadian rhythms.