Renoprotection in Early Diabetic Nephropathy in Pima Indians

Summary

This investigation is a randomized, double-blinded, placebo-controlled clinical trial in adult diabetic Pima Indians with normal urinary albumin excretion (albumin-to-creatinine ration less than 30 mg/g) or microalbuminuria (albumin-to-creatinine ration = 30-299 mg/g) to test the hypothesis that blockade of the renin-angiotensin system with the angiotensin receptor blocker (ARB) losartan can prevent or further attenuate the development and progression of early diabetic nephropathy in subjects with type 2 diabetes mellitus who are receiving standard diabetes care. One hundred seventy subjects were recruited for the study, all of whom had type 2 diabetes for at least 5 years, serum creatinine concentrations less than 1.4 mg/dl, and no evidence of non-diabetic renal diseases. Ninety-two of the subjects had normal urinary albumin excretion at baseline and other 78 had microalbuminuria. Subjects in each albumin excretion group were randomized to treatment with either the angiotensin II receptor antagonist, losartan, or placebo. Measurements of glomerular filtration rate (GFR), renal plasma flow (RPF) and fractional clearances of albumin and IgG will be made initially, at one month, and at 12-month intervals from baseline thereafter. A kidney biopsy was performed after six years in 111 subjects. Morphometric analysis of renal biopsies was used to determine differences in glomerular structure between treatment groups.

Timeline

Start

1995-08

Primary completion

2012-05

Completion

2014-03

Publications

• Background Zatz R, Meyer TW, Rennke HG, Brenner BM. Predominance of hemodynamic rather than metabolic factors in the pathogenesis of diabetic glomerulopathy. Proc Natl Acad Sci U S A. 1985 Sep;82(17):5963-7. doi: 10.1073/pnas.82.17.5963.
• Background Zatz R, Dunn BR, Meyer TW, Anderson S, Rennke HG, Brenner BM. Prevention of diabetic glomerulopathy by pharmacological amelioration of glomerular capillary hypertension. J Clin Invest. 1986 Jun;77(6):1925-30. doi: 10.1172/JCI112521.
• Background Anderson S, Rennke HG, Garcia DL, Brenner BM. Short and long term effects of antihypertensive therapy in the diabetic rat. Kidney Int. 1989 Oct;36(4):526-36. doi: 10.1038/ki.1989.227.
• Results Weil EJ, Fufaa G, Jones LI, Lovato T, Lemley KV, Hanson RL, Knowler WC, Bennett PH, Yee B, Myers BD, Nelson RG. Effect of losartan on prevention and progression of early diabetic nephropathy in American Indians with type 2 diabetes. Diabetes. 2013 Sep;62(9):3224-31. doi: 10.2337/db12-1512. Epub 2013 Apr 1.
• Natale P, Palmer SC, Navaneethan SD, Craig JC, Strippoli GF. Angiotensin-converting-enzyme inhibitors and angiotensin receptor blockers for preventing the progression of diabetic kidney disease. Cochrane Database Syst Rev. 2024 Apr 29;4(4):CD006257. doi: 10.1002/14651858.CD006257.pub2.
• Fort PE, Rajendiran TM, Soni T, Byun J, Shan Y, Looker HC, Nelson RG, Kretzler M, Michailidis G, Roger JE, Gardner TW, Abcouwer SF, Pennathur S, Afshinnia F. Diminished retinal complex lipid synthesis and impaired fatty acid beta-oxidation associated with human diabetic retinopathy. JCI Insight. 2021 Oct 8;6(19):e152109. doi: 10.1172/jci.insight.152109.
• Reynolds EL, Akinci G, Banerjee M, Looker HC, Patterson A, Nelson RG, Feldman EL, Callaghan BC. The determinants of complication trajectories in American Indians with type 2 diabetes. JCI Insight. 2021 May 24;6(10):e146849. doi: 10.1172/jci.insight.146849.
• Afshinnia F, Nair V, Lin J, Rajendiran TM, Soni T, Byun J, Sharma K, Fort PE, Gardner TW, Looker HC, Nelson RG, Brosius FC, Feldman EL, Michailidis G, Kretzler M, Pennathur S. Increased lipogenesis and impaired beta-oxidation predict type 2 diabetic kidney disease progression in American Indians. JCI Insight. 2019 Nov 1;4(21):e130317. doi: 10.1172/jci.insight.130317.
• Tanamas SK, Saulnier PJ, Fufaa GD, Wheelock KM, Weil EJ, Hanson RL, Knowler WC, Bennett PH, Nelson RG. Long-term Effect of Losartan on Kidney Disease in American Indians With Type 2 Diabetes: A Follow-up Analysis of a Randomized Clinical Trial. Diabetes Care. 2016 Nov;39(11):2004-2010. doi: 10.2337/dc16-0795. Epub 2016 Sep 9.
• Weil EJ, Lemley KV, Mason CC, Yee B, Jones LI, Blouch K, Lovato T, Richardson M, Myers BD, Nelson RG. Podocyte detachment and reduced glomerular capillary endothelial fenestration promote kidney disease in type 2 diabetic nephropathy. Kidney Int. 2012 Nov;82(9):1010-7. doi: 10.1038/ki.2012.234. Epub 2012 Jun 20.

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Indications