The long-range objective of this project is to prevent progression of diabetic nephropathy, the leading cause of end-stage renal disease (ESRD). In most patients diabetic nephropathy progresses inexorably to ESRD despite inhibition of the renin-angiotensin-aldosterone system with angiotensin converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs).
The specific aims of this proposal are to: 1) recruit a multi ethnic cohort of 72 young adults (ages 20-40) with type 1 (n=36) or type 2 (n=36) diabetes and overt nephropathy (defined as a urine albumin/creatinine ratio > 300 mg albumin/g creatinine) and randomize in a double blind fashion to a control group consisting of ACEI-based therapy alone (ramipril 40 mg once daily) or one of two experimental groups: a) ACEI + ARB (ramipril 40 mg once daily plus Iosartan100 mg once daily) or b) ACEI + mineralocorticoid receptor antagonist (MRA) (ramipril40 mg once daily plus spironolactone 25 mg once daily); 2) conduct a 12-month prospective study to determine if proteinuria is reduced to a greater extent when either the ARB or MRA is added to ACEi-based therapy. This study is powered to detect a 40% greater reduction in 24-hour urine albumin/creatinine ratio in either experimental group versus control (alpha= 0.05, beta=0.20, repeated measures analysis of variance). Secondary endpoints to be examined include:(a) serum potassium and creatinine to assess safety, (b) TGF-beta, as a surrogate marker for ongoing renal injury, (c) plasma renin activity, angiotensin II and aldosterone levels and (d) plasma lipids and lipoprotein composition; and 3) perform repeated ambulatory blood pressure monitoring (ABPM) to examine the renoprotective effect of the 3 different regimens at comparable 24-hour BP of < 125/75 mmHg. The deliverables include: 1) documentation of the safety of maximal dose combination therapy; 2) the feasibility of utilizing 24-hr ABPM to establish BP independent renoprotective effects of specific antihypertensive therapies; and 3) provide preliminary data for future large-scale studies to test efficacy and safety of combining ACEi with MIRA therapy on renal outcomes.
| Srivastava, Anand; Adams-Huet, Beverley; Vega, Gloria L et al. (2016) Effect of losartan and spironolactone on triglyceride-rich lipoproteins in diabetic nephropathy. J Investig Med 64:1102-8 |
| Van Buren, Peter N; Adams-Huet, Beverley; Nguyen, Mark et al. (2014) Potassium handling with dual renin-angiotensin system inhibition in diabetic nephropathy. Clin J Am Soc Nephrol 9:295-301 |
| Van Buren, Peter Noel; Adams-Huet, Beverley; Toto, Robert Daniel (2010) Effective antihypertensive strategies for high-risk patients with diabetic nephropathy. J Investig Med 58:950-6 |
| Mehdi, Uzma F; Adams-Huet, Beverley; Raskin, Philip et al. (2009) Addition of angiotensin receptor blockade or mineralocorticoid antagonism to maximal angiotensin-converting enzyme inhibition in diabetic nephropathy. J Am Soc Nephrol 20:2641-50 |
