Consistent sex differences in cortisol responses to psychological stress

Area of Science:

• Psychoneuroendocrinology
• Stress Physiology
• Sex Differences Research

Background:

• Cortisol, a key stress hormone, plays a vital role in the body's response to challenging situations.
• Previous research suggests potential sex differences in cortisol reactivity, but the underlying mechanisms remain unclear.

Purpose of the Study:

• To investigate sex differences in cortisol responses to acute psychological stress in healthy adolescents and adults.
• To explore the role of adrenocortical sensitivity and cognitive/emotional factors in observed sex disparities in stress hormone secretion.

Main Methods:

• Four independent studies involving 153 healthy participants (adolescents and adults).
• Psychological stress induction via public speaking and mental arithmetic tasks.
• Measurement of free cortisol levels before, during, and after stress exposure.
• Additional assessment of adrenocortical response to human corticotropin-releasing hormone (h-CRH) and physical exertion (bicycle ergometry).

Main Results:

• Psychological stress significantly increased cortisol levels (2-4 fold) in both sexes.
• Men exhibited 1.5-2 fold higher mean cortisol responses compared to women.
• Adrenocortical responses to h-CRH and physical exertion were similar between sexes.
• Men showed elevated cortisol during anticipation of stress, while women's levels remained unchanged or decreased.

Conclusions:

• The observed sex difference in cortisol response to psychological stress is unlikely due to lower female adrenal cortex responsiveness.
• Findings suggest that sex differences in cognitive and/or emotional processing of psychosocial stressors may mediate cortisol secretion.
• Further research is needed to elucidate the precise mechanisms underlying these sex-specific stress responses.