Pentosidine levels in nonproteinuric diabetes associated with both low estimated glomerular filtration rate and cataract

Xiu-Li Lim,^1,* Boon-Wee Teo,^2,* Bee-Choo Tai,¹ Tien Y Wong,³ Daniel P-K Ng<sup>1

1</sup>Department of Epidemiology and Public Health, ²Department of Medicine, Yong Loo Lin School of Medicine, National University Health System, ³Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore

^*Joint first authors

Background: The main objective of this study was to investigate whether plasma pentosidine levels were associated with cataract and low estimated glomerular filtration rate (eGFR) in nonproteinuric type 2 diabetic patients.
Methods: We characterized 888 nonproteinuric type 2 diabetic patients residing in Singapore according to their eGFR values. Proteinuria was excluded on the basis of multiple urinalyses. Patients with low renal function (cases, n = 125) and controls (n = 763) were defined as having eGFR < and ≥60 mL/min/1.73 m2, respectively. Pentosidine levels were measured by enzyme-linked immunosorbent assay. Multinomial logistic regression was used to test the association between plasma pentosidine levels and the joint phenotype of cataract and low eGFR.
Results: Cases had higher triacylglycerol values, higher systolic blood pressure, and were more likely to be treated with two or more antihypertensive medications. In univariate analysis, cases were potentially more than twice as likely to have had a history of cataract compared with controls. This association persisted in multivariate analyses after adjusting for the significant covariates, hypertension and triacylglycerol, but was attenuated when age was included in the model. Plasma pentosidine levels were significantly higher in cases with low eGFR who also had a history of cataract. This association persisted in multivariate analyses that included the covariates, glycosylated hemoglobin, hypertension, and diabetic retinopathy, as well as age.
Conclusion: Carbonyl stress, as reflected by pentosidine levels, is present in a subset of nonproteinuric diabetic patients. Clinically, this stress was associated with the joint presence of cataract and low eGFR.

Keywords: advanced glycation endproducts, Chinese, normoalbuminuria, renal function