Resting levels of stress hormones and their association with hand function in young women but not in men

Objectives: Manual dexterity is influenced by various physiological and cognitive factors. This study aimed to examine the association between resting salivary cortisol levels, “a biological marker of stress,” and hand function performance. Methods: Eighty-three healthy young adults (mean age: 22.8 ± 2.8 years; 40 women) were randomly assigned to two groups: One group ( n = 40) underwent testing in the morning only, while the other group ( n = 43) underwent both morning and evening assessments. Participants provided saliva samples and completed the Grooved Pegboard Test (GPT), which measures manual dexterity. Spearman’s correlation was used to evaluate associations between cortisol levels and GPT performance. Results: The mean GPT completion time was 63.8 ± 8.1 s. Cortisol levels were significantly higher in the morning (0.22 ± 0.12 mg/dL) than in the evening (0.15 ± 0.18 mg/dL). A positive correlation was observed between cortisol levels and GPT completion time across all participants (r = 0.27, P = 0.003). When analyzed by gender, a significant association was found in women (r = 0.39, P = 0.002), but not in men (r = 0.17, P = 0.18). Conclusion: Higher resting cortisol levels were associated with slower hand function performance in women, suggesting a gender-specific effect of stress hormone levels on manual dexterity.