[Insulin resistance: an etiological factor in essential arterial hypertension and coronary cardiopathy]

Insulin resistance has been implicated in the pathogenesis of essential hypertension. Studies from other countries discovered insulin resistance; in people with essential hypertension in was also associated with obesity, however, insulin resistance was found in lean people too. In obesity, insulin resistance occurs secondarily to many physiopathological states and circulating factors which adversely affects insulin action. The metabolic abnormality in this action was mainly found in relation to abdominal fat; in other cases, insulin resistance was found to be inherited. Hyperinsulinaemia can actually increase blood pressure and is associated with venous and arterial thrombosis and it also rises lipid levels. It is interesting too that insulin resistance and hyperinsulinaemia are associated with impaired fibrinolysis through high levels of fibrinogen and plasminogen activator inhibitor of endothelial type and in identifying individuals prone to myocardial infarction. Some antihypertensive drugs like beta-blockers, methyl-dopa and diuretics increase insulin resistance, while angiotensin converting enzyme-inhibitors have not shown any adverse metabolic affects. Alfa-1-blocker were beneficial and alfa-2-agonists were neutral, whereas calcium channel-antagonists are still in controversy. Treatment should be designed to improve the metabolic state; physical exercise, a diet rich in fruit, vegetable and rott vegetables, the reduction of abdominal fat and, finally, the use of antihypertensive drugs which decrease insulin resistance would be expected to reverse hyperinsulinaemia. Biguanides like metformin have also been found to reduce insulin resistance.