HDCN Article Review/Hyperlink

Nelson RG, Bennett PH, Beck GJ, et al for the Diabetic Renal Disease Study Group

Development and progression of renal disease in Pima Indians with non-insulin-dependent diabetes mellitus

New Engl J Med (Nov) 335:1636-1642 1996

The Pima Indians of the Gila River Indian Community in Arizona have the world's highest incidence of NIDDM with an incidence of ESRD that is more than 20 times that of the general U.S. population.

Glomerular function was determined at intervals of 6 to 12 months for 4 years in 194 Pima Indians. They were divided into 6 groups: (1) 31 non-diabetics with normal glucose tolerance; (2) 29 non-diabetics with impaired glucose tolerance; (3) 30 new-onset diabetics; (4) 20 with diabetes for > 5 yrs without microalbuminuria, i.e., urine albumin (mg/L) to urine creatinine (g/L) < 30; (5) 50 with diabetes for > 5 yrs with microalbuminuria (urine alb/creat ratio 30-299); (6) 34 with diabetes for > 5 yrs with macroalbuminuria (urine alb/creat ratio > 300).

Glomerular filtration rate was 143 +/- 7 ml/min in new-onset diabetics, 155 +/- 7 in those with microalbuminuria, and 124 +/- 7 in those with macroalbuminuria vs. 123 +/- 4 in subjects with normal glucose tolerance. During the four-year follow-up period, GFR increased by 18% in patients in new-onset diabetics (P=0.008), and fell by 35% in those with macroalbuminuria (average decline in GFR was 11 ml/min/yr). It did not change significantly in diabetics either without albuminuria or those with microalbuminuria. However, 37% of subjects with microalbuminuria developed macroalbuminuria; higher baseline blood pressure but not initial GFR predicted increasing albumin excretion. Initial GFR also did not predict a decrease in GFR with follow-up, suggesting that hyperfiltration itself is not the principal factor in the development or progression of nephropathy.

Comment: The role of hyperfiltration in the pathogenesis of renal disease remains unclear. A most interesting finding of this study is that hyperfiltration was present in all diabetics except those with macroalbuminuria; moreover, elevated GFR did not predict the later development of renal failure. In this study, microalbuminuria also did not predict a future decline in GFR; however, this finding contrasts with a previous study by Ravid et al (Ann Intern Med 1993; 118:577-81), in which renal function did subsequently decline in those with microalbuminuria. This discrepancy with respect to the prognosis of microalbuminuria may be explained by different methods of estimating GFR and/or by other factors, such as systemic blood pressure. (David J. Leehey, M.D., Loyola University at Chicago)

The abstract of this paper is available from the National Library of Medicine's PubMed site: click here .

For accompanying editorial by H-H Parving: Click here.