Effects of Antihypertensive Drugs on Skin Blood Flow as an Indicator of Sympathetic Responses to Mental Stress in Hypertensive Patients

The aim of this study was to clarify the response of sympathetic activity to antihypertensive drugs using a mental stress test in hypertensive patients and to determine the effects of antihypertensive drugs on the sympathetic activitymediated hemodynamic response to mental stress. Hypertensive patients were divided into three groups according to the type of drug(s) being taken: a calcium antagonist group, an angiotensin II receptor blocker group, and a combination therapy group of calcium antagonists and angiotensin II receptor blockers. The Stroop color-word conflict test was applied as a mental stress test and hemodynamic responses to mental stress were measured, including blood pressure, pulse rate, and skin blood flow. Elevation of blood pressure by mental stress was suppressed in the combination therapy group compared with the calcium antagonist group. Reduction of skin blood flow by mental stress was suppressed in both the angiotensin II blocker group and the combination therapy group compared with the calcium antagonist group. In conclusion, skin blood flow can be a useful tool to evaluate sympathetic activity and combination therapy with calcium antagonists and angiotensin II receptor blockers were the most useful therapy for suppressing the hemodynamic response to mental stress.