THE EFFECTS OF MENTAL STRESS AND ISOMETRIC HANDGRIP EXERCISE ON PERIPHERAL BLOOD CELL COUNTS IN PATIENTS WITH ESSENTIAL HYPERTENSION

Abstract

The effects of mental stress and isometric handgrip exercise on peripheral white blood cell counts and plasma active renin concentrations were studied in 20 patients with mild essential hypertension. The increases in blood pressure and pulse rate were similar for both provocations. Mental stress increased white blood cell (10.3±2.1%), platelet (2.8±1.6%), and red blood cell counts (1.7±0.3%). Isometric exercise also increased these blood cell counts (6.2±1.2%, 1.9±0. 8%, 1.0±0.3%, respectively). The increase in white blood cell counts with mental stress was significantly greater than that in response to isometric exercise. With both provocations, the increase in white blood cell counts was significantly greater than those in platelet and red blood cell counts. There was a positive correlation between the increases in white blood cell counts and systolic blood pressure with mental stress (r = 0.49, p<0.05). Mental stress increased plasma concentrations of active renin and aldosterone, but isometric exercise did not affect these hormones. These results indicate that both white blood cell counts and concentrations of renin and aldosterone are higher in mental stress than in isometric exercise. It is possible that leukocytosis induced by mental stress damages target organ in hypertensive patients.