HDCN Article Review/Hyperlink

Guasch A, Parham M, Zayas C, Campbell O, Nzerue C, Macon E

Contrasting effects of calcium channel blockade versus converting enzyme inhibition on proteinuria in African Americans with NIDDM nephropathy

J Am Soc Nephrol (May) 8:793-798 1997

Black patients, particularly older black patients, tend to respond better to calcium antagonists than to ACE inhibitors. However, in black patients with NIDDM and proteinuria, the renal effects of antihypertensive drugs need to be considered. In Caucasian patients, dihydropyridine calcium antagonists (DHP-CAs) sometimes worsen proteinuria, whereas non-dihydropyridine calcium antagonists (NDHP-CAs) may have a beneficial effect. For example, Bakris et al showed that the antiproteinuric effects of verapamil or diltiazem were similar to those of lisinopril and better than atenolol in patients with NIDDM. In blacks specifically with established diabetic renal disease, Bakris et al showed that verapamil was shown to be more renoprotective than atenolol. In contrast to the apparent renoprotective effects of NDHP-CAs, dihyropyridine CAs (DHP-CAs) are known to have no effect on proteinuria in diabetes, e.g., see Abbott et al. In this paper, Guasch et al simply extend what is known in general re DHP-CAs and proteinuria in NIDDM specifically to black patients with this disease.

They randomized 31 black patients with NIDDM and proteinuria (about 3g/day) to receive either isradipine (a DHP-CA) or captopril. 29/31 were hypertensive, and the washout period before baseline assessment was quite short (2 weeks), during which time BP was controlled with clonidine plus a diuretic. The drugs doses were isradipine 2.5 BID or captopril 25 mg TID. After a 6 month follow up period, despite similar final levels of BP control, proteinuria had increased by 50% in the isradipine group whereas it had decreased by about 30% in the ACE inhibitor group. Because initial systolic BP was slightly higher in the isradipine group, the change in BP actually tended to be greater in the isradipine group.

Comment: Although the results confirm that DHP-CAs are not the drug of choice for patients with NIDDM and proteinuria, use of NDHP-CAs in African American patients with NIDDM and proteinuria may have a beneficial effect, and in particular, combination therapy with ACE inhibitors and NDHP-CAs may be of benefit. (John T. Daugirdas, M.D., University of Illinois at Chicago)