Clinical Utility of Urinary β2-Microglobulin in Detection of Early Nephropathy in African Diabetes Mellitus Patients

Background. 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 (β2m) was investigated in this study as a potential biomarker in the detection of early nephropathy in type 2 diabetics. Methods. 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 β2m levels and urinary albumin concentration (UAC) were determined. Results. Elevated urinary β2m 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 β2m and UAC (rho = 0.38, p < 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. Conclusion. Urinary β2m may be useful, either as a single test or as a component of a panel of tests, in the early detection of diabetic nephropathy.