CALCIUM-CHANNEL BLOCKERS VERSUS OTHER ANTIHYPERTENSIVE THERAPIES ON PROGRESSION OF NIDDM ASSOCIATED NEPHROPATHY

Treatment of hypertension with ACE inhibitors in diabetic patients red uces proteinuria and slows progression of nephropathy compared with ag ents that do not maintain declines in proteinuria. Calcium channel blo ckers (CCBs) have variable effects on proteinuria; their long-term eff ects on progression of diabetic nephropathy are not known. The current study examines the hypothesis that CCBs that maintain reductions in p roteinuria slow progression of nephropathy associated with non-insulin dependent diabetes mellitus (NIDDM) by a degree comparable to ACE inh ibitors, given similar levels of blood pressure control. To test this hypothesis we randomized 52 patients with NIDDM associated nephropathy and hypertension, mean age of 63 +/- 8 years, to either the ACE inhib itor, lisinopril (N = 18), nondihydropyridine CCBs (NDCCBs), verapamil SR (N = 8) or diltiazem SR (N = 10), or the beta blocker, atenolol (N = 16). Goal blood pressure was less than or equal to 140/90 mm Hg. Pa tients were followed for a mean period of 63 +/- 7 months. The primary end point was change in creatinine clearance (C-Cr) slope in each gro up. There was no significant difference in mean arterial pressure redu ction among the groups over the study period (P = 0.14). The mean rate of decline in C-Cr was greatest in the atenolol group (-3.48 ml/min/y ear/1.73 m(2); P < 0.0001). There was no difference in the C-Cr slopes between lisinopril and NDCCBs groups (P = 0.36). Proteinuria was redu ced to a similar extent in the lisinopril and NDCCBs groups (P > 0.99) . Therefore, in persons with renal insufficiency secondary to NIDDM, s imilar levels of blood pressure control with either lisinopril or NDCC Bs slowed progression of renal disease to a greater extent than atenol ol. Moreover, this enhanced slowing of renal disease progression corre lated with sustained and significant reductions in proteinuria, findin gs not observed in the atenolol group.