Psychophysiologic sensitization to headlight glare among professional drivers with and without cardiovascular disease.

Previous studies have shown that young, healthy professional drivers show heightened central nervous system arousal and cardiovascular hyperreactivity to simulated headlight glare. Electroencephalographic and cardiovascular response and recovery to simulated headlight glare (the glare pressor test) were examined in 4 groups of male professional drivers (age 25-52 years)--12 with ischemic heart disease (IHD), 12 with hypertension (HTN), 10 with borderline hypertension (BHTN), and 34 who were healthy--and in 23 non-professional driver controls--with the aim of assessing sensitization to this night driving stressor in relation to degree of cardiovascular disease severity. After glare exposure the IHD drivers showed the most pronounced alpha blockade, a rise in diastolic blood pressure (DBP; p < .05), and, unlike the other groups, a persistent fall in finger pulse volume (p < .02). The BHTN group reacted initially with DBP rise and finger pulse drop (ps < .05 and .02, respectively), mainly without central nervous system arousal. The DBP remained constant in normotensive professional drivers older than 40. The drivers' cardiovascular responses to glare were inversely related to reported stressors and subjective experience. Anxiety trait and long work hours were associated with heightened central arousal to glare in professional drivers. The results suggest that there may be progressive degrees of sensitization to glare exposure in these samples, with the least among normotensive professional drivers older than 40, moderate levels in borderline hypertensives, and the most severe in drivers with IHD.