Association between serum gamma-glutamyltransferase and chronic kidney disease among US adults

Serum gamma-glutamyltransferase (GGT), a biomarker of oxidative stress, is associated with an increased risk of diabetes and hypertension. However, it is not known whether higher serum GGT is independently associated with chronic kidney disease (CKD). Therefore, we examined the association between serum GGT levels and CKD in a representative sample of US adults.

We conducted a cross-sectional study of 9,516 National Health and Nutrition Examination Survey 1999-2002 participants >or=18 years of age (52.40% women). Serum GGT was categorized into quartiles for the analysis. CKD (n = 622) was defined as an estimated glomerular filtration rate of <60 ml/min/1.73 m(2).

Higher serum GGT levels were not associated with CKD after adjusting for age, sex, race/ethnicity, education levels, smoking, alcohol intake, body mass index (BMI), diabetes, hypertension and serum cholesterol. Compared to quartile 1 of GGT, the odds ratio (95% confidence interval) of CKD associated with quartile 4 was 1.02 (0.81-1.28); p trend = 0.377. Subgroup analyses that examined the relation between GGT and CKD by gender, alcohol intake, and BMI categories also showed a consistent null association. In summary, there was no association between increasing levels of serum GGT and CKD in a sample of US adults.