CORTISOL AND HEART-RATE CHANGES IN FIRST-TIME AND FOURTH-TIME DONORS

It is well-known that during blood donation some subjects experience m ild, moderate, or severe stress reactions. The frequency of these reac tions is higher in first-time donors than in experienced ones. However , hormonal variations might nevertheless be present in subjects who sh ow no clinical reaction. Cortisol is the hormone classically involved in response to stress. The aim of this study was to evaluate cortisol behavior in blood donors who did not manifest clinical reaction. Corti sol was studied before and after the first and fourth blood donation i n 20 blood donors, aged 25-45 years. Blood pressure and heart rate wer e also evaluated. Plasma cortisol concentrations decreased during the first (from 202.6+/-9.2 ng/ml at -15 min, to 147.5+/-8.0 ng/ml, at +30 min; p<0.001), but not during the fourth (142.5+/-7 ng/ml vs. 153.0+/ -10.1 ng/ml) blood donation; blood pressure remained stable throughout donations, while the heart rate significantly decreased (from 78 to 6 8 beats/min; p<0.001) only during the first experience. The increased cortisol levels observed before the first donation are apparently due to emotional components, since they were not observed in experienced d onors. We may conclude that blood donation per se is not a stressful e vent and that moderate stress, as suggested by the increased cortisol levels and heart rate at the first donation, is secondary to emotional rather than to physical factors and occurs during a never-experienced -before event.