High, low serum uric acid tied to CKD risk in women

Both high and low levels of serum uric acid (UA) aggravate the risk of worsening renal function and chronic kidney disease (CKD) in females, a recent study has found. In males, on the other hand, only high UA is a risk factor.

The study included 6,779 participants (mean age, 45±9 years; 2,325 females) whose annual medical data were reviewed retrospectively. Measurements of UA, along with other blood markers, were collected in the morning, after an overnight fast. CKD was defined as a decline in estimated glomerular filtration rate (eGFR) to <60 mL/min/1.73m².

Participants were followed for a mean of 9.6 years, during which time CKD developed in 509 male and 271 female participants. The resulting incidence rates were 11.4 percent and 11.7 percent, respectively. At baseline, serum UA was significantly higher in males (6.1±1.2 vs 4.3±0.9 mg/dL; p<0.001).

Grouping participants according to UA quintiles showed that in females, UA concentration shared a U-shaped correlation with CKD development. Using the 4th quintile as a reference, restricted cubic spline analysis revealed significantly elevated risks of incident CKD on the top (hazard ratio [HR], 1.68, 95 percent confidence interval [CI], 1.14–2.47) and bottom (HR, 1.73, 95 percent CI, 1.08–2.77) UA categories.

Such an interaction was absent in males, however, where the relationship between UA and CKD was weak and linear. Using the first quintile as a reference, those belonging to the top quintile saw a marginally higher risk of CKD (HR, 1.39, 95 percent CI, 0.96–2.00). None of the risk estimates in any of the quintiles achieved statistical significance.