LAWRENCE W FAULKNER,
RESEARCH AND REPORTS
Salivary Cortisol Levels in Students Challenged with a Testing Stressor
KATHLEEN KENWRIGHT, PATTY W LIDDELL, LEONARD BLOOM, AUDREY ZUCKER-LEVIN, ANN H NOLEN, LAWRENCE W FAULKNER, ROSEMARY E BATORSKI
OBJECTIVE: The objective was twofold. The focus of the study was primarily to determine if the stress of a particularly difficult exam could cause students to lose the normal diurnal variation seen in human cortisol levels and secondarily, to validate the use of a competitive enzyme immunoassay for salivary cortisol.
inDESIGN: Physical therapy students enrolled Research Design were asked to participate in the study by collecting baseline evening and morning salivary Cortisols during what was regarded as a relatively stress free time in the Fall of 2009. The following spring, the same students were asked for samples the evening before and morning of their first Kinesiology test, traditionally a stressful time. Method validation was accomplished using instrumentation owned by the Medical Laboratory Science (MLS) Program and analysis was performed by MLS faculty and a second year MLS student.
SETTING: Participants were enrolled in the College of Health Sciences at the University of Tennessee in Memphis. Sample collection and testing was performed in the student laboratory of the Medical Laboratory Science Program.
PARTICIPANTS: Physical therapy students in their first year of a three-year entry level doctorate program, DPT.
RESULTS: This group of students did not lose their diurnal variation of cortisol. However, an unexpected finding was noted: the students’ salivary cortisol specimen collected in the morning of the fall semester was significantly higher than the salivary cortisol specimen collected the morning of the test in the spring semester (p = .019). Method validation was successful demonstrating a strong correlation ( r = 0.915) when compared to the reference laboratory.
CONCLUSIONS: Cortisol diurnal variation was not lost in the study participants, but further studies should be performed due to the low percentage of students completing the study and the lack of demographic diversity. Even though the method validation in the student laboratory setting demonstrates that it is indeed possible to obtain the same excellent correlation as is seen in a clinical setting, the student laboratory is not CLIA certified, so assays can be performed for research use only.
ABBREVL\TIONS: ACTH-adrenocorticotropic hor- mone, CRH-corticotrophin-releasing hormone, DPT- Doctorate in Physical Therapy, BS-Baccalaureate of Science, BA-Baccalaureate of Arts, IRB-Internal Review Board, GPA-Grade Point Average, EIA-Enzyme Immunoassay, BMI-Basic Metabolic Index, CLIA- Clinical Laboratory Improvement Amendments, ND- none detected
INDEX TERMS: stress, cortisol, exams, students
Clin Lab Sei 2011;24(4):221
Kathleen Kenwright, MS, MT,(ASCP)SL,MB”^, University of Tennessee Health Science Center, Memphis,
TN38163.
Patty W. LiddellMS, MT(ASCP)SH, Baptist College of Health Sciences, Memphis, TN 38163
Leonard Bloom MPH, CT(ASCP), The University of Tennessee Health Science Center, College of Allied Health Sciences, Memphis, TN.
Audrey Zucker-Levin PT, PhD, MBA, GCS, The University of Tennessee Health Science Center, College of
Allied Health Sciences, Memphis, TN.
VOL 24. NO 4 FALL 2011 CLINICAL LABORATORY SCIENCE 221
RESEARCH AND REPORTS
Ann H. Nolen, Psy.D., OTR, FAOTA, The University of
Tennessee Health Science Center, College o/^Allied Health Sciences, Memphis, TN.
Lawrence W. Faulkner, Ph.D. OTIL, The University of
Tennessee Health Science Center, College of Allied Health
Sciences, Memphis, TN.
Rosemary E. Batorski, MEd, MOT, OTR, The University of Tennessee Health Science Center, College of
Allied Health Sciences, Memphis, TN
Address for Correspondence: Kathleen Kenwright, MS, MT,(ASCP)SI,MB^^, University of Tennessee Health Science Center, 930 Madison Avenue, Suite 672, Memphis, TN 38163, 901-448-6338, kkenwrig@uthsc. edu
INTRODUCTION Cortisol is a steroid hormone produced by the adrenal glands in response to adrenocorticotropic hormone (ACTH) secreted by the pituitary.’ The typical ditirnal variation of cortisoi secretion has been well established. Cortisol shows an increase in the early morning hours, peaking at or slightly before the time of waking, and decreases in the evening.’ This hormone plays an important role in maintaining homeostasis by affecting multiple organ systems and processes. Under stressful situations, the body responds by increasing the production of cortisoi by initiating a series of events involving the hypothalamus, pituitary and adrenal cortex called the H PA axis. Specifically, corticotrophin- releasing hormone (CRH) released by the hypothalamus triggers release of adrenocorticotropic hormone (ACTH) from the pituitary which in turn causes the secretion of glucocorticoids from the adrenal cortex.’ The strength of the stimulus causes some variation in circadian peak levels and the normal variation has been shown to be disrupted during times of stress.^
Effect on memory Though elevated cortisoi in response to stress is a natural response, it is sometimes detrimental for students in that some forms of memory are impaired. There is abundant evidence that the secretion of glticocorticoid stress hormones may modulate memory functioning.’* The frontal lobe and hippocampus in humans contain a high density of glucocorticoid receptors and are areas for cognition and emotion.
During times of stress there may be a pronounced deficit in working memory but at the same time, enhancements may be seen associated with other forms of memory.’
MATERIAL AND METHODS Multidisciplinary Project
Four departments within the College of Allied Health at the University of Tennessee Health Science Center participated in various aspects of this project. The following outlines some goals anticipated by the faculty of the departments involved in the study.
The purposes of this multidisciplinary project were to: r- Validate salivary cortisoi in our Clinical
Laboratory Science (MLS) student laboratory. ” Determine if the stress of an exam would cause
students to lose their normal diurnal variation of cortisoi.
‘- Determine if there is a correlation between cortisoi concentration and a test grade. Determine if there is a correlation between students’ perceived stress and the biological marker of stress-cortisol. To serve as a working example of research design to physical therapy students starting a research course.
— Provide opportunities for multi-disciplinary scholarly activity to tenured and non-tenured faculty.
This paper will focus on only two aspects of the study: the method validation and whether or not the students lose their diurnal variation when challenged with a Stressor.
Participants After IRB approval was obtained, the entire student body, of the first year physical therapy class, was approached at the beginning of a structured lecture to ask for their participation in the project. These students were in their fourth month (4”’) of a thirty three (33) month entry-level Doctor of Physical Therapy (DPT) program. All students had a BA or BS degree prior to admission to the program. The study was explained in detail and informed consent was obtained from 50 students. Of these 50 students, 23 completed the research protocol. The students who completed the study were on average 23 (± 1.21) years old; 18 female.
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