Gender differences in cardiovascular responses to the cold hand pressor test and facial cooling.

To test the hypothesis that changes in systemic vascular resistance (SVR) contribute to the differences in arterial blood pressure responses between men and women to local cold pressor tests, nine normotensive men (25.9 +/- 5.9 years old) and women (24.4 +/- 5.9 years old) performed the cold hand pressor test (CPT; 6 min in 5 degrees C water) in the supine position. A subgroup of men (n = 5) and women (n = 5) from the CPT were exposed to 6 min of facial cooling (FC) by circulating cold water (5 degrees C) through a perfusion mask. Using standard auscultatory techniques, pre-experimental systolic and diastolic blood pressures were found to be significantly higher (p < or = 0.05) in males than females. During the initial 2 min of CPT and FC, both males and females experienced similar relative increases in pressure. Thereafter, only the males maintained an elevated pressor response, whereas the females progressively declined. The gender-related trends in blood pressure can be explained by differences in SVR, with the males exhibiting significantly greater changes in SVR than females during min 4-6 in CPT. Heart rate increased (p < or = 0.05) in both groups, with the greater rise occurring in females at each minute of CPT. Throughout FC, the changes in SVR were similar between groups, with the exception of the 6-min value being greater than baseline in men but not women. No differences in heart rate or cardiac output were observed between groups during FC.(ABSTRACT TRUNCATED AT 250 WORDS)