Biomedical subjects

N Nicolson

Publications and source records attributed to N Nicolson.

4 recordsLinked to original sources

PubMed1997

Salivary cortisol levels and stress reactivity in human aging.

BACKGROUND: While homeostatic mechanisms are generally believed to become less efficient in the aging organism, evidence for changes in hypothalamic-pituitary-adrenal function is inconclusive. Previous studies report higher, lower, or unchanged basal cortisol levels in human aging. Delayed recovery of glucocorticoids to baseline following stress exposure has been observed in aging rats, but the generalizability of these findings to humans remains unclear. METHODS: Salivary-free cortisol was measured at home and in response to a laboratory speech task in 56 healthy men and women in three age groups (range 43-86 yr). RESULTS: Higher basal cortisol levels were observed in older age groups. Gender, recent life stress, and current distress showed no relationship to basal levels. The magnitude of cortisol responses to the speech task differed by age, with the smallest responses in the oldest group. This pattern was robust in men, with the youngest subjects (40-59 yr) showing both the largest and the most prolonged responses. While women > 70 yr were least likely to show any response, other analyses failed to show age effects on reactivity in women, perhaps because anticipatory baseline elevations limited subsequent cortisol response. CONCLUSIONS: Results indicate moderate increases in basal cortisol levels, but do not support the hypothesis that cortisol responses to a stressor increase in magnitude or duration during normal human aging. Gender differences in stress reactivity warrant further investigation.

Adult↗

PubMed1991

Coping style, trait anxiety and cortisol reactivity during mental stress.

The present study examined whether salivary cortisol secretion as an index of stress reactivity to continuous mental task performance reflected individual differences in coping styles. During 4 hr of continuous mental tasks significantly higher cortisol levels were found in comparison with a control session. However, individual variability in the cortisol response was high. Correlational data indicate a significant negative relationship between the coping style 'comforting cognitions' and the individual cortisol response during mental stress. During this particular type of cognitive stress, where the subject has no control over the experimental situation, comforting and emotion-focused coping may be effective because of the subject's efforts of trying to reframe the inevitable situation in a positive and self-encouraging way. In contrast, there was no significant relationship between trait anxiety and individual glucocorticoid susceptibility to mental stress.

Adaptation, Psychological↗

PubMed1990

Cortisol reactivity and cognitive performance in a continuous mental task paradigm.

The after-effects of fatigue or stress on the performance of cognitive tests have been particularly difficult to demonstrate. In this study we examined whether salivary cortisol, used as an index of stress evoked by the continuous performance of mental tasks, reflected individual differences in cognitive performance. In a within-subject experiment in which 24 subjects were exposed to 4 hours of continuous mental activity and to a control session, significantly higher cortisol levels were found during the continuous task session. Cognitive performance was assessed before and after each session. The relevant test parameters involved aspects of verbal memory, concept shifting and divided attention. When subjects were divided into two groups based on the magnitude of individual cortisol responses to the continuous tasks, it was found that the subgroup with higher cortisol responses decreased in attention compared with their attention after the control session. In contrast, the performance of the subgroup with no or lower cortisol responses did not differ between the two sessions. There was no evidence of similar effects on verbal memory or concept shifting.

Adult↗

PubMedDate not supplied

The effects of perceived stress, traits, mood states, and stressful daily events on salivary cortisol.

This study examined the effects of perceived stress and related individual characteristics, mood states, and stressful daily events on salivary cortisol levels. Forty-one "high stress" and 46 "low stress" subjects were selected on the basis of Perceived Stress Scale scores from a sample of male, white collar workers. Subjects completed Experience Sampling self-reports and collected saliva samples 10 times a day over 5 consecutive days. Multilevel analysis revealed that trait anxiety and depression, but not perceived stress, were associated with small but statistically significant cortisol elevation. No effects on cortisol were found for recent life events, chronic difficulties, trait anger, or psychosomatic symptoms. Distress, as reflected by the mood states Negative Affect and Agitation, was associated with higher cortisol levels, whereas Positive Affect had no statistically significant effect. Stressful daily events were associated with increased cortisol secretion, the magnitude of the effect depending on whether the event was still ongoing and on how frequently a similar kind of event had occurred previously. Although perceived stress, anxiety, and depression did not increase cortisol reactivity to daily events, we found evidence for reduced habituation to recurrent events in subjects scoring high on these traits. Mood appeared to play a mediating role in the relationship between stressful events and cortisol secretion. These results suggest that negative affectivity is not just a confounder but is related to elevated cortisol secretion during normal daily activities. The finding that even minor events and fluctuations in mood states were associated with increased adrenocortical activity points to a possible mechanism linking subjective experience to health outcomes.

Adult↗