The Effect of an Academic Examination on Salivary Norepinephrine and Immunoglobulin Levels

The effect of academic stress on immune function, as measured by the rate of secretion of salivary secretory immunoglobulin A (s-IgA), was studied prospectively in 64 first-year dental school students. Perceived stress and s-IgA secretion rate were measured five times--during an initial low-stress period, three high-stress periods coinciding with major examinations, and a final low-stress period. The s-IgA secretion rate was significantly lower in high-stress than low-stress periods for the whole group. In addition, personality characteristics differentiated patterns of s-IgA secretion rates. Students characterised by a great need to establish and maintain warm personal relationships secreted more s-IgA at each point than did all other subjects. The s-IgA secretion rates of those with a high inhibited need for power continued to decline through the final low-stress period rather than recovering as in all other subjects.

Previous research has reported that individuals high in the need for Power, high in inhibition, and high in power stress (the HHH group) are more likely than other individuals to report more severe illnesses. The present study investigates the possibility that the mechanism underlying this relationship is greater sympathetic activation in the HHH group which has an immunosuppressive effect. College males with the HHH syndrome reported more frequent and more severe illnesses than other individuals, as in previous studies. More of the HHH than other subjects also showed above average epinephrine excretion rates in urine and below average concentrations of immunoglobulin A in saliva (S-IgA). Furthermore, higher rates of epinephrine excretion were significantly associated with lower S-IgA concentrations, and lower S-IgA concentrations were significantly associated with reports of more frequent illnesses. The findings are interpreted as consistent with the hypothesis that a strong need for Power, if it is inhibited and stressed, leads to chronic sympathetic overactivity which has an immunosuppressive effect making individuals characterized by this syndrome more susceptible to illness.