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Applications Of Hair As A Record Of Systemic Exposure To Cortisol, Jeffrey Matthew Levine

Electronic Thesis and Dissertation Repository

Hair cortisol content (HCC) is a novel biomarker that uniquely captures retrospective systemic cortisol exposure. This thesis aimed to assess how different hair growth rates effect HCC timelines in Cushing’s and Addison’s patients, investigate the relationship between HCC and age, puberty, sex and BMI in healthy children and adolescents, and assess novel methods to improve cortisol extraction and recovery. Retrospective HCC timelines derived from a 0.75 cm/month growth rate best matched 50% of patients’ medical records rather than the historically assumed 1 cm/month. HCC correlated positively with age (p<0.0001), puberty status (p<0.001), and BMI (p<0.01) in males and females 7-17 years old. Nitrogen evaporation resulted in greater cortisol recovery than air evaporation (p=0.0003), and hair digestion using NaOH resulted in more rapid extraction of cortisol. These results provide incremental improvements to previous methods and assumptions for HCC analysis and elucidate normal HCC changes in children and adolescents.