The association between the red cell distribution width and diabetic nephropathy in patients with type-2 diabetes mellitus.

BACKGROUND: Red cell distribution width (RDW) has been reported to be involved in metabolic syndrome and cardiovascular events. Patients with diabetic nephropathy (DN) are often found to be with high level of RDW. The aim of this study was to explore whether RDW was associated with DN severity and progression in patients with type-2 diabetes mellitus (T2DM).

METHODS: A total of 175 T2DM patients with biopsy-proven DN were enrolled. The baseline clinical and pathologic data of these patients was extracted from the medical records. The patients then were divided into two groups based on the median (13.6%) of RDW level; group 1: <13.6% and group 2: ≥13.6%. The effect of RDW level on the renal outcomes was evaluated by using cox regression analysis.

RESULTS: Compared with the patients with lower RDW level, the patients with higher level of RDW had higher proportions of female, longer DM duration, lower levels of eGFR, albumin and hemoglobin, and more serious glomerular damage. Moreover, the RDW levels were negatively corrected with eGFR (r = -0.283, p < 0.001), but positively related with proteinuria (r = 0.227, p = 0.003). In the follow-up period, 81(46.3%) patients had reached ESRD from baseline. Importantly, the Cox regression analyses showed that the levels of RDM had a significant effect on the risk of progression to ESRD (HR = 1.92, p < 0.01), albeit not emerged as an independent predictor.

CONCLUSIONS: These data indicated that the levels of RDW were significantly associated with increased risk of progression to ESRD in patients with DN, despite did not an independent predictor.