Background: Rapid decline of renal function in a diabetic suggests the presence of a nondiabetic kidney disease (NDKD). We designed a prospective study to evaluate the factors associated with a rapid decline in renal function in patients with type 2 diabetes.
Methods: Over a 2 and a half year period, all patients with type 2 diabetes who presented with documented doubling of serum creatinine in less than 4 weeks or recently diagnosed advanced renal failure were identified. Patients with prerenal causes, urinary tract obstruction, or systemic disease causing renal failure were not included. Renal histology was studied in all cases.
Results: A total of 26 patients satisfied the inclusion criteria. Over 75% had serum creatinine >4 mg/dL at presentation and 62% were dialysis dependent. Renal histology showed mixed lesions of diabetic nephropathy (DN) and NDKD in 11 cases, only DN in nine, and pure NDKD in six. Diffuse proliferative glomerulonephritis (DPGN) was the commonest NDKD (27% cases), all on a background of DN. History of preceding cutaneous or pharyngeal infection was available in five cases. The proportion of postinfectious glomerulonephritis in diabetics with rapidly progressive renal failure was over six times that of the nondiabetic adult RPRF population during the study period. Four patients had acute interstitial nephritis and three showed crescentic glomerulonephritis. Other lesions included amyloidosis, atheroembolic disease, and renal papillary necrosis (one each). The frequency of microscopic hematuria and retinopathy was similar in those with pure DN and NDKD. Four out of seven cases with DPGN showed partial recovery whereas the other three remained unchanged.
Conclusions: About two-thirds of patients with type 2 diabetes presenting with rapid decline of renal function in a tropical environment show NDKD. The high incidence of postinfectious glomerulonephritis in this group is possibly related to the high prevalence of skin and soft tissue infections; and could contribute to progressive kidney disease.