Hostility and caffeine: cardiovascular effects during stress and recovery

Both hostility and caffeine are frequently cited as potential factors in co ronary heart disease (CHD). The present study examined the independent and interactive effects of these important variables on cardiovascular function ing. The Cook-Medley Scale was used to select 24 high and 24 low hostile su bjects, who received caffeine (400 mg) or a placebo (lactose) in a double-b lind design. All completed mental arithmetic (MA) and anagram stress tasks during which they experienced periods of verbal harassment and non-harassme nt. Blood pressure and heart rate were recorded. The combination of high ho stility and harassment increased diastolic blood pressure (DBP) and maintai ned elevated levels of mean arterial pressure (MAP) during task periods, wh ile reducing DBP recovery during rest periods. Caffeine increased systolic blood pressure (SBP) and interacted with harassment to create an inverted-U effect, reducing blood pressure. Finally, hostility and caffeine interacte d to maintain elevated levels of DBP during recovery periods. These results support the dual-interactional theory of personality and behavior, which s uggests an interaction of genetic and environmental factors and of disposit ional and situational factors. (C) 2001 Elsevier Science Ltd. AH rights res erved.