Should all Pima Indians with type 2 diabetes mellitus be prescribed routine angiotensin-converting enzyme inhibition therapy to prevent renal failure?

Abstract

OBJECTIVE: To determine how effective angiotensin-converting enzyme (ACE) inhibitors must be in preventing diabetic nephropathy to warrant early and routine therapy in all Pima Indians with type 2 diabetes mellitus. DESIGN: A computerized medical decision analysis model was used to compare strategy 1, screening for microalbuminuria and treatment of incipient nephropathy as currently recommended with ACE inhibitor therapy, with strategy 2, a protocol wherein all patients were routinely administered an ACE inhibitor 1 year after diagnosis of type 2 diabetes mellitus. The model assumed that ACE inhibitors can block, at least in part, the pathogenic mechanisms responsible for early diabetic nephropathy (microalbuminuria). RESULTS: The model predicted that strategy 2 would produce more life-years at less cost than strategy 1, if routine drug therapy reduced the rate of development of microalbuminuria by 21% in all patients. Only a 9% reduction in the rate of development of microalbuminuria was cost-effective at $15,000 per additional life-year gained, and only a 2.4% reduction was cost-effective at $75,000 per additional life-year gained for strategy 2 over strategy 1. CONCLUSIONS: Routine ACE inhibitor therapy in Pima Indians with type 2 diabetes mellitus could prove more effective and even cost saving than the currently recommended approach of microalbuminuria screening. A prospective trial examining this goal should be considered.