Cortisol concentrations in serum of borderline hypertensive men exposed to a novel experimental setting.

We tested the effect of repeated exposure to a novel experimental setting on resting, morning blood cortisol concentrations in borderline hypertensive men. Borderline hypertension is thought to be accompanied by increased central nervous system activation, which would predict enhanced anticipation and cortisol secretion in a novel experimental situation. Twenty-two borderline hypertensive and 23 normotensive male volunteers were tested in four sessions all separated by 2 or more days. Borderline hypertensives had higher cortisol concentrations than normotensives during the first and second days (p < .005) but not on the third and fourth days. Significant reductions in cortisol concentrations across days were noticed in borderline hypertensives but not in normotensives. All subjects reported feeling more activated on the first day than on any other day (p < .01). These results indicate that exposure to a novel experimental situation may enhance secretion of stress related hormones such as cortisol in borderline hypertensives.