The Level of Serum Albumin Is Associated with Renal Prognosis in Patients with Diabetic Nephropathy

Abstract

Objective. Although hypoalbuminemia is frequently found in most patients with diabetic nephropathy (DN), its relationship to the severity and progression of DN remains largely unknown. Our aim was to investigate the association between the serum albumin levels and clinicopathological features and renal outcomes in patients with type 2 diabetes mellitus (T2DM) and biopsy-proven DN. Materials and Methods. A total of 188 patients with T2DM and biopsy-proven DN followed up for at least one year were enrolled. The patients were divided into four groups based on the albumin levels: normal group: ≥35 g/L ( $n=87$); mild group: 30-35 g/L ( $n=34$); moderate group: 25-30 g/L ( $n=36$); and severe group: <25 g/L ( $n=31$). The renal outcome was defined by progression to end-stage renal disease. The impact of the serum albumin level on renal survival was estimated using Cox regression analysis. Results. Among the cases, the serum albumin level had a significant correlation with proteinuria, renal function, and glomerular lesions. A multivariate Cox regression analysis indicated that the severity of hypoalbuminemia remained significantly associated with an adverse renal outcome, independent of clinical and histopathological features. In reference to the normal group, the risk of progression to ESRD increased such that the hazard ratio (HR) for the mild group was 2.09 (95% CI, 0.67-6.56, $p=0.205$), 6.20 (95% CI, 1.95-19.76, $p=0.002$) for the moderate group, and 7.37 (95% CI, 1.24-43.83, $p=0.028$) for the severe group. Conclusions. These findings suggested that hypoalbuminemia was associated with a poorer renal prognosis in patients with T2DM and DN.