Higher cortisol content in hair among long-term unemployed individuals compared to controls

Background: Unemployment and financial strain are chronic stressors that have been shown to be associated with an increase in mean salivary and serum cortisol levels. The impact of chronic stress on cortisol excretion is best measured using a summary index of cortisol excretion over longer periods of time rather than momentary assessments. Hair analysis for cortisol content is a new promising tool by which hair segmental analysis may provide a retrospective calendar of cumulative cortisol exposure. Methods: Participants of this study were 31 unemployed and 28 employed individuals (n=46 women). Hair segmental analysis was conducted using 3cm -long segments starting with the scalp-near segment. Due to differing hair length, n=52 individuals had values for the second segment and n=33 individuals had values for the third segment. Results: Univariate analysis of variance indicated that unemployed individuals had higher cortisol content in the first (p<0.05, eta2=0.071) and second (p<0.05, eta2=0.085) hair segment (a total of 6cm long hair representing the preceding 6 months of collection). Duration of unemployment was related to hair cortisol content (r=0.415 and r=0.430 for segment 1 and 2, respectively). Interestingly, BMI was related to hair cortisol content (r=0.430) but was not different between groups. Consistent with other data from our laboratory, there was a wash-out effect for the third segment (p<0.05 for segment 3 vs. segment 1 and 2). Conclusions: We conclude that hair analysis for cortisol content may be a valid method to detect differences in cumulative cortisol exposure between chronically stressed individuals and healthy controls. Due to a wash-out effect, retrospective ascertainment of cortisol exposure may be limited to the preceding 6 months of specimen collection.