Mild hyperuricemia and subclinical renal damage in untreated primary hypertension

Am J Hypertens. 2007 Dec;20(12):1276-82. doi: 10.1016/j.amjhyper.2007.08.010.


Background: Subclinical renal damage and hyperuricemia are not uncommon in patients with primary hypertension. Whether mild hyperuricemia reflects a subclinical impairment of renal function or contributes to its development is currently debated. We investigated the relationship between serum uric-acid levels and the occurrence of early signs of kidney damage.

Methods: Four hundred eighteen patients with primary hypertension were studied. Albuminuria was measured as the albumin-to-creatinine ratio, and creatinine clearance was estimated by the formula of Cockcroft and Gault. Interlobar resistive index and renal abnormalities, ie, the renal volume-to-resistive index ratio, were evaluated by renal Doppler and ultrasound.

Results: Uric acid was directly related to resistive index (P = .007) in women and to albuminuria (P = .04) in men, and was inversely related to the renal volume-to-resistive index ratio in both men (P = .005) and women (P = .02). Patients with uric-acid levels above the median showed a higher prevalence of microalbuminuria (14% v 7%, P = .012) and of renal abnormalities (41% v 33%, P = .007). Moreover, when creatinine clearance was taken as a covariate, patients with increased uric-acid levels showed higher albuminuria and resistive indices, and a lower renal volume-to-resistive index ratio. Even after adjustment for several risk factors, each standard deviation increase in serum uric acid entailed a 69% higher risk of microalbuminuria, and a 39% greater risk of ultrasound detectable renal abnormalities.

Conclusions: Mild hyperuricemia is associated with early signs of renal damage, ie, microalbuminuria and ultrasound-detectable abnormalities, regardless of the glomerular filtration rate in primary hypertension.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Glomerular Filtration Rate
  • Humans
  • Hypertension / complications*
  • Hyperuricemia / diagnosis*
  • Hyperuricemia / etiology*
  • Kidney Diseases / diagnosis*
  • Kidney Diseases / etiology*
  • Male
  • Middle Aged