Evidence-Based Treatment of Hypertension in Patients With Type 2 Diabetes

The incidence of diabetes, and in particular of diabetes type 2, has been rising dramatically over the past few decades. Currently, diabetes type 2 accounts for more than 90% of the diabetic population (1). Macroand microvascular disease, including diabetic nephropathy, with their clinical complications are the principal causes of morbidity and mortality in patients with diabetes. Due to the epidemic proportions of the rise in diabetes cases, the excessive morbidity and mortality and the high costs associated with the treatment of diabetic complications, the socio-economic burden of diabetic renal disease has become dramatic (2). About half of the patients diagnosed with type 2 diabetes also have hypertension. The relationship between hypertension and renal disease in type 2 diabetes is different than in type 1 diabetes. Whereas in type 1 diabetes the presence of hypertension usually indicates renal involvement, many patients with type 2 diabetes are hypertensive even without microalbuminuria. Patients may even be hypertensive for years prior to the onset of diabetes, as part of a metabolic syndrome characterized by insulin resistance, obesity, dyslipidemia and hypertension. The combination of diabetes and hypertension strongly predisposes a patient to cardiovascular complications. It has been reported that 35-75% of diabetic cardiovascular and renal complications can be attributed to hypertension (3). Thus, aggressive blood pressure control has been advocated as a means of preventing or delaying the progression of these complications. Many different antihypertensive agents have been shown to be effective in reducing blood pressure in type 2 diabetes and there is general agreement that blood pressure reduction per se is beneficial for these patients. However, the choice of the antihypertensive drug may also affect the risk of clinical complications and some drugs may be more beneficial than others. The effects of different antihypertensive regimens on diverse end points in type 2 diabetes have been examined in numerous clinical trials, often with conflicting results. The present communication aims to discuss the renoprotective effects, as well as the effects on cardiovascular morbidity and mortality of different antihypertensive drugs and different blood pressure targets in patients with type 2 diabetes. This may help to formulate guidelines for clinicians to select the optimal anthypertensive therapy in this patient population.