Measurement of urinary advanced glycation end-products (AGEs) using a fluorescence assay for metabolic...

The simple screening test of advanced glycation end-products (AGEs) has not been established yet. We aimed to clarify the usefulness of simple measurement of AGEs for screening tests.

The subjects were healthy participants and patients with metabolic syndrome. Urine samples were diluted from 1:10 to 1:200 using phosphate-buffered saline, and the fluorescence intensity was measured at 440nm after excitation at 370nm in a 96-well microplate spectrophotometer. The obtained intensities were adjusted according to the urinary creatinine levels.

In patients with metabolic syndrome, urinary AGE levels were significantly higher than in healthy individuals (median [range], 168.25 [82.51-1276.15] AU/g creatinine [n=37] versus 134.67 [37.86-776.31] AU/g creatinine [n=350], respectively; p=0.0066). We found significant positive correlations between urinary AGEs and systolic and diastolic blood pressures (Spearman's correlation r=0.119 [p=0.019] and r=0.128 [p=0.012], respectively). There was no significant correlation between estimated glomerular filtration rate and urinary AGEs (r=0.018 [p=0.744]), confirming that renal dysfunction did not influence results of urinary AGE measurements. When all of the participants in the study were classified into four groups according to the numbers of components of metabolic syndrome, we found a significant tendency (p=0.0127) for urinary AGE levels to be higher with the increasing number of metabolic syndrome components.

These results suggested that measurement of urinary AGE levels may be useful for evaluating the risk of metabolic syndrome.