Clinical implications of pathophysiologic changes in the midlife hypertensive patient.

Both aging and hypertension decrease cardiac output through a lower stroke volume and a diminished beta-adrenergic responsiveness. In parallel, the vascular resistance increases because of vascular hypertrophy. In addition, in hypertension the alpha-adrenergic responsiveness is enhanced. Aging and hypertension are also associated with an increase in plasma cholesterol and insulin values. These alterations in cholesterol and insulin levels become particularly pronounced in middle-aged patients with hypertension. alpha-Adrenergic-blocking agents have a positive effect on lipids and insulin resistance. The shift toward enhanced alpha-adrenergic responsiveness, and the fact that vasodilators do not diminish exercise performance favor the use of alpha-blockers as a first drug in middle-aged patients with hypertension. Blood pressure lowering still remains the paramount goal, and these compounds should be used only if proved to be efficacious in a given individual patient.