Circadian variations of blood pressure and pulse rate in essential hypertensives with diabetes mellitus.

1. The circadian variations of blood pressure and pulse rate in essential hypertensives either with or without diabetes mellitus were studied. 2. Diabetic patients with orthostatic hypotension showed an increase in variability of blood pressure and a decrease in that of pulse rate when assessed by coefficient of variation. Cosinor analysis showed no significant circadian rhythm in both blood pressure and pulse rate in these patients. 3. There were no differences in the circadian variations of blood pressure and pulse rate between essential hypertensives with and without diabetes mellitus unless orthostatic hypotension was present. 4. These results suggest that diabetes mellitus per se does not have any effects on the circadian variations of blood pressure and pulse rate in essential hypertensives unless autonomic neuropathy is present.