Even a slight increase within the normal range of serum uric acid levels may be a risk factor for kidney damage in the general population, according to Japanese researchers.
They used a nationwide database of 165,847 individuals aged 29–74 years who participated in the annual “Specific Health Check and Guidance in Japan” checkup from 2008–2010.
Keita Kamei, MD, of Yamagata University School of Medicine in Yamagata, Japan, and colleagues examined the relationship between serum uric acid levels at baseline and the 2-year change in estimated glomerular filtration rate (eGFR). Compared with the first quintile of serum uric acid level, the fourth and fifth quintiles were associated with a significant 10% and 20% increased odds of incidental renal insufficiency (eGFR below 60 mL/min/1.73 m2), after adjusting for age, gender, obesity, hypertension, and other variables, Dr. Kamei’s group reported online ahead of print in Nephrology Dialysis Transplantation. Each 1 mg/dL increment in uric acid level was associated with a significant 5% increased odds of renal insufficiency.
The first quintile of uric acid level was 4.9 mg/dL or less in men and 3.7 mg/dL or less in women. The fourth quintile was 6.3–7.0 mg/dL in men and 4.9–5.4 mg/dL in women. The fifth quintile was 7.1 mg/dL or higher in men and 5.5 mg/dL or higher in women.
Normal uric acid levels are 3.4–7.0 mg/dL in men and 2.4–6.0 mg/dL in women.