Serum Carboxymethyl-Lysine, a Dominant Advanced Glycation End Product, Is Associated With Chronic Kidney Disease: The Baltimore Longitudinal Study of Aging

Abstract

Advanced glycation end products (AGEs) are modifiable risk factors for renal disease that were primarily studied in persons with diabetes or endstage renal disease. Our objective was to characterize the relationship between AGEs and renal function in community-dwelling adults. The presence of serum L-carboxymethyl-lysine (CML), a dominant AGE, was compared with renal function in a cross-sectional analysis. This study was part of the Baltimore Longitudinal Study of Aging in Baltimore, Maryland. Participants included community-dwelling men and women, aged 26 to 93 years, seen during a regular follow-up visit to the Baltimore Longitudinal Study of Aging between 2002 and 2007. The main outcome measures included chronic kidney disease (CKD) at stage >/=3 of the National Kidney Foundation classification (estimated glomerular filtration rate [eGFR] of<60 mL/minute/1.73 m(2)) and eGFR. Of 750 adults, 121 (16.1%) had CKD. Serum CML was associated with CKD (odds ratio expressed per one standard deviation, 1.37; 95% confidence interval, 1.11 to 1.67; P=.003) in a multivariate logistic regression model adjusting for age, race, smoking, and chronic diseases. Serum CML was associated with eGFR (mL/minute/1.73 m(2)) (beta=-2.21, standard error=0.57, P=.0001) in a multivariate linear regression model, adjusting for age, race, smoking, and chronic diseases. After excluding patients with diabetes, serum CML was associated with CKD (odds ratio per one standard deviation, 1.38; 95% confidence interval, 1.12 to 1.70; P=.003) and eGFR (beta=-2.09, standard error=0.59, P=.0005), adjusting for the same covariates. Serum CML, a dominant AGE, is independently associated with CKD and eGFR.