Effects of interferon on circadian changes in blood pressure and heart rate variability in patients with chronic hepatitis.

We have determined the effects of interferon therapy on circadian changes in blood pressure and heart rate variability in normotensive hospitalized patients with chronic active hepatitis. Body temperature and pulse rate increased for the initial few days of interferon therapy without significant change in casual or ambulatory blood pressure. Interferon therapy failed to elicit any significant changes in the power spectrum of R-R intervals. In addition, urinary excretion of norepinephrine did not differ between before and during the therapy. These results suggest that interferon therapy caused transient increases in body temperature and pulse rate, but that it did not change either sympathetic or parasympathetic outflow, or the circadian rhythm of blood pressure and heart rate variability, in normotensive subjects.