IS ELEVATED BLOOD-PRESSURE LEVEL ASSOCIATED WITH HIGHER CARDIOVASCULAR RESPONSIVENESS IN LABORATORY TASKS AND WITH RESPONSE SPECIFICITY

Cardiovascular responsiveness and response specificity were investigat ed in male students, 48 with moderately elevated blood pressure (systo lic blood pressure [SEP] > 140 mmHg and/or diastolic blood pressure [D BP] > 90 mmHg), 31 with mildly elevated blood pressure, and 57 with no rmal blood pressure. The behavioral tests and physically demanding tas ks in the laboratory included mental arithmetic, free speech condition , cold presser test, upright tilt, and ergometer exercise. Subjects wi th elevated blood pressure differed in baseline, task, and recovery le vels of SEP, DBP, and heart rate. There were no significant effects in task - baseline differences or in residualized change scores. However , a positive initial-value dependency (LIV) in blood pressure response s was found: elevated blood pressure is associated with a larger incre ase under task conditions. Response scaling that employed reliability estimates and true difference scores indicated higher responsiveness i n subjects with moderately elevated blood pressure and, thus, are in a ccordance with the positive LIV as compared with response measures bas ed on task - baseline differences or residualized change scores. Findi ngs from the specificity analysis indicated a higher incidence of SEP responders, that is, subjects with maximum response in SEP, among subj ects with elevated blood pressure. Some of the inconsistencies in the literature with respect to blood pressure responsiveness and heart rat e level in individuals with borderline hypertension may be attributed to the specific method of response scaling and to insufficient habitua tion to the setting and measurement.