Diabetes modifies cardiovascular reactivity during hypertension.

Hypertension and diabetes often occur in the same patient, and this observation inspired the search for a new common pathogenetic hypothesis. The onset of diabetes during hypertension also could modify cardiovascular autonomic arousal. To identify a peculiar hemodynamic and psychophysiologic reactivity, a male population of mild essential hypertensive (166 +/- 6/102 +/- 8 mm Hg) patients (EH) and noninsulin-dependent hypertensive (169 +/- 10/101 +/- 7 mm Hg) diabetic subjects (HD) underwent a session of stress tests. Four tests, Mental Arithmetic, Incomplete Phrases, Cold Presser, and Handgrip, were preceded and followed by a 10-minute recovery period. Functional tests were performed to identify any possible cardiac autonomic neuropathy. During the entire session, by means of a beat-to-beat noninvasive computerized device, hemodynamic and extracardiovascular functions were measured. The findings suggested the presence of a sympathetic hyperactivity in both HD and EH. In particular, HD showed a peculiar "tropism" for the peripheral vasculature. In these patients, in fact, total vascular resistance and peripheral temperature responses were 89.2% and -64.2%, respectively, versus 33.7% and -50.6%, which were found in EH. On the other hand, the ejection ventricular index was more depressed in HD (-27.9%) than in EH (-23.8%), although they did not seem to be affected by cardiac autonomic damage. The different profiles appear to confirm the increase of functional vascular damage in diabetic hypertensive patients, probably because of the insulin resistance or obsolete muscular cardiac damage.