Diabetes Care, Vol 11, Issue 10 821-827, Copyright © 1988 by American Diabetes Association
Etiology and prevalence of hypertension in diabetic patients
DC Simonson
Department of Internal Medicine, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215.
Data from several epidemiologic studies have suggested that the prevalence
of hypertension in patients with diabetes mellitus is approximately 1.5-2.0
times greater than in an appropriately matched nondiabetic population. In
patients with insulin-dependent diabetes mellitus (IDDM), hypertension is
generally not present at the time of diagnosis. As renal insufficiency
develops, blood pressure rises and may exacerbate the progression to
end-stage renal failure. In non-insulin-dependent diabetes mellitus
(NIDDM), many patients are hypertensive at the time of diagnosis. The
incidence of hypertension in NIDDM is related to the degree of obesity,
advanced age, and extensive atherosclerosis that is typically present, and
it probably includes many patients with essential hypertension. Several
other pathophysiologic mechanisms also contribute to the genesis and
maintenance of hypertension in the patient with diabetes. Hyperglycemia and
increases in total-body exchangeable sodium may lead to extracellular fluid
accumulation and expansion of the plasma volume. In some patients,
alterations in the function of the renin-angiotensin-aldosterone system and
vascular sensitivity to vasoactive hormones may also play a role. It has
recently been suggested that hyperinsulinemia and insulin resistance may
also contribute to the maintenance of an elevated blood pressure because
insulin is known to promote sodium retention and enhance sympathetic
nervous system activity. The evidence for these hypotheses and their
respective contributions to the etiology of hypertension in IDDM and NIDDM
are discussed.