[Association between serum uric acid and early kidney damage in middle-aged and elderly]

To investigate the association between serum uric acid (UA) and early kidney damage and the prevalence of early kidney damage [89 >or= GFR >or= 60 ml * min(-1) * (1.73m(2))(-1)] in the middle-aged and elders with normal serum creatinine.

A survey of cardiovascular risk factors, including serum UA and estimated glomerular filtration rate (eGFR) [according to MDRD (modification of diet in renal disease) equation], was carried out in a local general population of Chengdu. A total of 1023 subjects with normal serum creatinine [mean age: (63 +/- 6) years; male: female = 52.7%: 47.3%] were recruited by random sampling method. The subjects were divided into 4 groups (A, B, C, D) according to the quartiles of serum UA levels (A: UA < 282 micromol/L, B: 282 micromol/L or= 379 micromol/L).

In the group, the prevalence of early kidney damage was 28.1% (men: 35.8% > women: 19.5%, P < 0.01). In men and women, serum UA and mild kidney dysfunction were negatively correlated, and the prevalence of early kidney damage significantly increased with the elevated level of serum UA. The prevalence of early kidney damage was higher in men than women (P < 0.01). According to the logistic regression analysis adjusting for age, gender, waist, body mass index, triglyceride, HDL-C, total cholesterol, history of hypertension and diabetes type 2, the odds ratio of the prevalence of early kidney damage were 1.0 [B: 1.740 (P = 0.151), C: 3.599 (P = 0.01) and D: 5.488 (P < 0.01) respectively].

In the middle-aged and elders with normal serum creatinine, serum UA and eGFR are negatively correlated. And serum UA level is independently associated with early kidney damage.