Alpha 1 blockers: antihypertensives whose positive metabolic profile with regard to hyperinsulinaemia and lipid metabolism cannot be ignored.

The selective alpha 1-adrenoceptor-blocking agents constitute effective monotherapy in the control of essential hypertension. The failure of well-controlled trials of other antihypertensives to achieve the expected reduction in coronary heart disease has given rise to speculation that the antihypertensives used are atherogenic because of metabolic changes induced in the patient. The selective alpha 1-adrenoceptor blockers have positive effects on carbohydrate metabolism, hyperinsulinaemia and lipid metabolism. These changes, which consist of a modest reduction in total serum cholesterol, an increase in high-density-lipoprotein cholesterol, and a decrease in low-density lipoprotein, very-low-density lipoprotein and triglyceride, accompanied by a reduction in hyperglycaemia and serum insulin levels, have been observed in hypertensive patients. Experimental studies using isolated tissue culture and intact animal systems have confirmed these observations. The changes in metabolism may represent the key to prevention of coronary heart disease in the hypertensive population.