Blood pressure variations to be considered in the treatment of hypertension

Diurnal variations of the basal blood pressure in patients with essential hypertension were investigated by the indirect recording methods. To estimate the reduction in blood pressure at midnight, disturbance of sleep in the patients should be considered. Relationship between neurohumoral factors and the diurnal blood pressure variations were also evaluated. 1) Variations of the casual blood pressure at the clinic visits may be stabilized beyond 15 minutes of the sitting rest. 2) During the out-patient treatment of essential hypertension with placebo for 6 weeks, 16% of the patients showed reduction in mean arterial pressure of 13 mmHg or more. 3) Significant influence of seasons on blood pressure was not apparent for 6 weeks of the placebo treatment of hypertension. But in patients under the long-term antihypertensive treatment, blood pressure in summer was maintained significantly lower than in winter. 4) Self-monitoring of blood pressure by patients at home is valuable for estimating diurnal changes of blood pressure with the antihypertensive treatment.