Nondrinkers in the highest tertile of serum uric acid levels are at the highest risk for chronic kidney disease (CKD), new findings suggest. Moderate alcohol drinkers in the lowest tertile of serum uric acid levels have the lowest risk of the disease.

In an observational study of 9116 healthy Japanese men aged 40 to 55 free of hyperuricemia, CKD, proteinuria, diabetes, and hypertension at baseline, CKD developed in 1230 of them over 11 years. Having elevated serum uric acid levels increased the risk of CKD by 1.4-, 1.6-, 2.3-, and 3.1-fold for quintiles 2, 3, 4, and 5 of serum uric acid (range 5.1–12.9 mg/dL), respectively, compared with quintile 1 (0.5–5.0 mg/dL), Tomoshige Hayashi, MD, PhD, of Osaka City University, and colleagues reported in the American Journal of Nephrology. Independently, moderate alcohol consumption (23.1 to 46.0 g ethanol daily) decreased CKD risk by 45% compared with no drinking. Heavy drinking decreased the risk by 41%.

In a joint analysis of serum uric acid levels and average daily alcohol consumption in association with CKD risk, moderate drinkers in the lowest tertile of serum uric acid (0.5‒5.5 mg/dL)—the reference group—had the lowest risk of CKD and nondrinkers in the highest tertile of serum uric acid (6.7‒12.9 mg/dL) had 3.9-fold higher risk of CKD compared with the reference group. The investigators adjusted for age, body mass index, blood pressure, fasting plasma glucose, smoking habits, and physical activity.

The findings corroborate 4 previous studies from the United States, Japan, Korea, and the Netherlands examining uric acid levels and alcohol consumption or CKD. This is the first study to investigate the joint relationship of serum uric acid and alcohol consumption with kidney disease, according to the researchers. They speculated that elevated urate eventually damages glomeruli and the tubulointerstitium and separately induces insulin resistance. Alcohol consumption might increase insulin sensitivity.

The study lacked information about beverage types, which is a limitation. Beer is known to increases serum uric acid regardless of purine content, the investigators said. Wine possibly does not increase it.

“Our study does not support the recommendation of alcohol consumption to those who do not currently drink,” Dr Hayashi and the team concluded. “Further research is required to evaluate the significance of uric acid-lowering strategies and appropriate alcohol consumption to prevent CKD or delay its onset.”

Reference

Okada Y, Uehara S, Shibata M, et al. Habitual alcohol intake modifies the relationship of uric acid to incident chronic kidney disease. Am J Nephrol. DOI: 10.1159/000500707