Diabetes and hypertension: prognostic and therapeutic considerations.

Hypertension and diabetes are common disorders which frequently co-exist. Both are risk factors for atherosclerotic vascular disease and their combination is associated with an increased incidence of nephropathy, ischaemic heart disease, peripheral vascular disease, and stroke. Several trials such as the HDFP and SHEP studies that included diabetic patients have demonstrated the beneficial effects of antihypertensive therapy in reducing mortality. In diabetes, studies have focussed predominantly on the efficacy of antihypertensive therapy in reducing the progression of diabetic kidney disease. Such therapy has been shown to decrease albuminuria in the setting of "normal" and elevated blood pressure in both type I and type II diabetic patients. This reduction in albuminuria has been observed in microalbuminuric diabetic patients and also in those with overt renal disease. Recent studies in type I diabetic patients with overt nephropathy indicate that these effects on urinary albumin excretion are associated with reduction in the rate of decline in renal function and development of end-stage renal failure. Indeed, several groups have shown that the initiation of antihypertensive therapy improves the prognosis of type I diabetic patients with nephropathy. While certain classes of drugs may reduce the rate of progression of complications such as nephropathy, others have side effect profiles that are disadvantageous in patients with diabetes.