Clinical trial NCT00340678: Renoprotection in Early Diabetic Nephropathy in Pima Indians
Official title: Renoprotection in Early Diabetic Nephropathy in Pima Indians
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE3
Conditions: Diabetic Nephropathy
Keywords: Angiotensin II Receptor Antagonist
Therapeutic Trial
Glomerular Filtration Rate
Kidney Biopsy
Non-Insulin Dependent Diabetes Mellitus
Lead sponsor: National Institutes of Health Clinical Center (CC)
Sponsor class: NIH
First posted: 2006-06-21
Enrollment: 170
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief 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.

Detailed description: This investigation is a randomized, double-blinded, placebo-controlled clinical trial in adult diabetic Pima Indians with normal urinary albumin excretion (albumin-to-creatinine ratio \< 30 mg/g) or microalbuminuria (albumin-to-creatinine ratio = 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 \< 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 the 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 immunoglobulin G (IgG) were made initially, at one month, and at 12-month intervals from baseline thereafter. A kidney biopsy was be performed after six years in 111 subjects. Morphometric analysis of renal biopsies was used to determine differences in glomerular structure between treatment groups.

The major outcome measure was a decline in GFR to less than or equal to 60 ml/min or to half the baseline value in subjects that enter the study with a GFR of \< 120 ml/min. Other measures of renoprotection were assessed, including group differences in 1) change in albumin excretion, 2) change in serum creatinine concentration, and 3) glomerular morphology in all subjects as outlined above.

Eligibility criteria: * INCLUSION CRITERIA:

Volunteers from the Gila River Indian Community who meet the eligibility criteria will be invited to participate.

To be eligible for participation in the study, subjects must meet the following criteria:

* Aged 18-65.
* Diagnosis of type 2 diabetes greater than or equal to 5 years.
* Serum creatinine concentration less than to 1.4 mg/dl.
* Serum potassium concentration less than or equal to 5.5 milliequivalents (mEq)/L.
* At least 2 of 3 weekly screening urinary albumin-to-creatinine ratios less than 300 mg/g. All screening tests are to be within 3 months of enrollment.
* Willingness, after receiving a thorough explanation of the study, to participate.

EXCLUSION CRITERIA:

Subjects will be excluded for the following reasons:

* Clinically significant disorders of the liver, cardiovascular disease, cerebrovascular disease, peripheral vascular disease, pulmonary diseases, renal-urinary disorders, gastrointestinal disorders, or hematocrit levels less than or equal to 30 percent in women or less than or equal to 35 percent in men.
* Renovascular or malignant hypertension; uncontrolled hypertension despite treatment with three antihypertensive drugs; or hypertension that is being treated with antihypertensive medicines and the primary care physician or the patient refuses to adopt the blood pressure treatment regimen outlined in the study protocol.
* Hematuria of unknown etiology.
* Chronic debilitating disorders with or without treatment that would interfere with the assessment of kidney function or that might reduce the chances of survival for a sufficient length of time to evaluate efficacy of treatment.
* Currently receiving a drug regimen that includes: steroids, immunosuppressants, or investigational new drugs.
* Pregnancy. Women of childbearing potential must have a negative pregnancy test prior to entry and every three months during the study.
* Evidence of inability to empty the bladder.
* Hypersensitivity to angiotensin-converting enzyme inhibitors (ACEi), ARBs, or iodine.
* Bleeding disorders, since kidney biopsies could not be performed safely in these individuals.
* Massive obesity with body mass index greater than or equal to 45 kg/m(2).
* Non-diabetic renal disease.
* Conditions that are likely to interfere with informed consent or compliance with the protocol.

Primary outcomes:
measure: Number of Participants With Decline in GFR
timeFrame: Up to 6 years
Secondary outcomes:
measure: Glomerular Volume
timeFrame: 6 years after first treatment
Other outcomes:
Locations:
city: Phoenix
country: United States
facility: NIDDK, Phoenix
state: Arizona
Study officials:
affiliation: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
name: Robert G Nelson, M.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: 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.
citation: 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.
citation: 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.
citation: 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.
citation: 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.
citation: 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.
citation: 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.
citation: 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.