Clinical Utility of Urinary<i>β</i>2-Microglobulin in Detection of Early Nephropathy in African Diabetes Mellitus Patients

Abstract

<i>Background</i>. Studies have indicated that diabetic tubulopathy may occur earlier than glomerulopathy, therefore providing a potential avenue for earlier diagnosis of diabetic nephropathy. Urinary beta-2-microglobulin (<i>β</i>2m) was investigated in this study as a potential biomarker in the detection of early nephropathy in type 2 diabetics. <i>Methods</i>. One hundred and two diabetic subjects and 103 controls that met the inclusion criteria had data (sociodemographic, medical history, physical examination, and laboratory) collected. Urinary <i>β</i>2m levels and urinary albumin concentration (UAC) were determined. <i>Results</i>. Elevated urinary <i>β</i>2m was more frequent among the diabetics (52%, 95% CI: 42.1-61.8%) than among the controls (32%, 95% CI: 22.9-41.2%). The frequency of microalbuminuria was higher in the diabetics (35.3%, 95% CI: 25.9-44.7%) than in the controls (15.5%, 95% CI: 8.4-22.6%). There was a positive correlation between urinary <i>β</i>2m and UAC (rho = 0.38, <i>p</i> < 0.001). Multivariate analysis showed BMI (OR: 1.23, 95% CI: 1.05-1.45), eGFR (OR: 0.97, 95% CI: 0.94-0.99), and presence of microalbuminuria (OR: 3.94, 95% CI: 1.32-11.77) as independent predictors of elevated urinary beta-2-microglobulin among the diabetics. <i>Conclusion</i>. Urinary <i>β</i>2m may be useful, either as a single test or as a component of a panel of tests, in the early detection of diabetic nephropathy.