The return of increased blood pressure after discontinuation of anti hypertensive treatment is associated with an impaired post-ischemic skin blood flow response

Objective To assess the post-ischemic skin blood flow response after withdr awal of anti hypertensive therapy in hypertensive patients with normal bloo d pressure during treatment. Design and Methods Twenty hypertensive patients (group A) with a normal cli nic blood pressure (< 140/90 mmHg) receiving antihypertensive treatment (an y monotherapy; one pill per day for at least 6 months) had their treatment discontinued. Before medication withdrawal and 2, 4, 12 and 24 weeks therea fter, the following measurements were made: clinic blood pressure, home blo od pressure (three times per week, morning and evening) and skin blood flow response to a 5 min forearm arterial occlusion (using laser Doppler flowme try). The patients were asked to perform an ambulatory blood pressure recor ding at any time if home blood pressure was greater than or equal to 160/95 mmHg on two consecutive days, and treatment was initiated again, after det ermination of the skin hyperemic response, if daytime ambulatory blood pres sure was greater than or equal to 140/90 mmHg. The same studies were perfor med in 20 additional hypertensive individuals in whom antihypertensive trea tment was not withdrawn (group B). The allocation of patients to groups A a nd B was random. anti hypertensive treatment. In patients in group A2 a sig nificant attenuation of the hyperemic response was also observed. This impa ired response was present even at the end of the 6 month follow-up, at whic h time the patients were still untreated but exhibited a significantly grea ter blood pressure than before drug discontinuation. The hyperemic response of patients who did not stop treatment (group B) did not change during the course of the study. Results The data fom 18 patients in group A who adhered strictly to the pro cedure were available for analysis. Seven of them had to start treatment ag ain within the first 4 weeks of follow-up; four additional patients started treatment again during the next 8 weeks (group A1). The seven other patien ts remained untreated (group A2). The skin hyperemic response decreased sig nificantly in patients in group A1 and returned to baseline values at the e nd of the study, when there were again receiving. Conclusions Our findings show a decrease in the postischemic skin blood flo w response after withdrawal of antihypertensive treatment in hypertensive p atients. This impaired response may be due to the development of endothelia l dysfunction, vascular remodeling, or both, and might contribute to the re turn of blood pressure to hypertensive values after withdrawal of anti hype rtensive therapy. (C) 2001 Lippincott Williams & Wilkins.