BACKGROUND:
The aim of this study was to evaluate the clinical characteristics of nondiabetic nephropathy in
type 2 diabetes mellitus patients and to find a
clinical significance of renal
biopsy and immunosuppressive
treatment in such a
patient.
METHODS:
Renal
biopsy results, clinical
parameters, and renal outcomes were analyzed in 75 diabetic
patients who underwent
kidney biopsy at Chungnam National
University Hospital from January 1994 to December 2010.
RESULTS:
The three most common reasons for renal
biopsy were nephrotic range
proteinuria (44%),
proteinuria without
diabetic retinopathy (20%), and unexplained decline inrena lfunction (20.0%). Ten
patients (13.3%) had only
diabetic nephropathy (Group I); 11
patients (14.7%) had
diabetic nephropathy with superimposed nondiabetic nephropathy (Group II); and 54
patients (72%) had only nondiabetic nephropathy (Group III).
Membranous nephropathy (23.1%),
IgA nephropathy (21.5%), and acute
tubulointerstitial nephritis (15.4%) were the three most common nondiabetic nephropathies. Group III had shorter duration of diabetes and lesser
diabetic retinopathy than Groups I and II (P = 0.008).Group II had the lowest baseline estimated
glomerular filtration rate (P = 0.002), with the greatest proportion of renal deterioration during follow-up (median 38.0 months, P < 0.0001). The
patients who were treated with intensive
method showed better renal outcomes (
odds ratio 4.931; P = 0.01). Absence of
diabetic retinopathy was associated with favorable renal outcome in intensive
treatment group (
odds ratio 0.114; P = 0.032).
CONCLUSION:
Renal
biopsy should be recommended for type 2 diabetic
patients with a typical nephropathy because a considerable number of these
patients may have nondiabetic nephropathies. And intensive
treatment including
corticosteroid or
immunosuppressants could be recommended for type 2 diabetic
patients with nondiabetic nephropathy, especially if the
patients do not have
diabetic retinopathy.