Introduction: Only a few studies have reported quantitative sensory testing (QST) reference values for healthy African Americans, and those studies are limited in sample size and range of age of participants. The intent of our study was to fill a gap in the understanding of pain and somatosensory function in African Americans by generating QST values for healthy African American adults. In a large cohort of pain-free, healthy African American adults whose past pain experiences and current psychological status were known, our study aim was to determine thermal and mechanical QST values and compare those values at the anterior forearm by age and sex. We also determined the values for 5 other body sites and compared the values for differences by testing site location (upper body versus lower body). Methodology: In this cross-sectional study, 124 pain-free African American adults (age 18 to 69 years, 49% female) completed demographic and self-reported pain, fatigue and psychosocial measures. QST included obtaining thermal and mechanical responses and associated pain intensity levels. We applied the Benjamini-Hochberg procedure to adjust the p values to account for the multiple t tests. Results: We found thermal detection values at the anterior forearm were (29.2°C±1.6) for cool detection (CD) and (34.5°C±1.2) for warm detection (WD). At that site, pain thresholds were: cold pain threshold (CPTh) (26.3°C±5.0), heat pain threshold (HPTh) (37.8°C±3.6), and mechanical pain thresholds (MPTH) (16.7±22.2 grams of force, gF). There was a significant between sex difference for WD, with women being more sensitive (q=0.027). Lower body sites were less sensitive than upper body sites across all thermal modalities (q<0.003), but not for the mechanical modality. Mean pain intensity scores rated immediately after the CPTh and HPTh were 1.9 ± 1.3 to 2.2 ± 1.2 on the 0-10 pain intensity scale. Similarly, after the MPTh tests the mean pain intensity scores were 0.5 ± 0.5 to 0.8 ± 0.6. These scores did not differ significantly by sex or age group and clearly indicate that the participants reported pain threshold at an appropriately low perceptual intensity. Pain intensity values for past pain experiences and low ratings for fatigue, depression and anxiety indicated that these factors were unlikely contributors to their pain threshold reports. Conclusion: The QST values from this protocol at the anterior forearm indicate that healthy African American adults had average thermal pain thresholds within 6°C of the temperature of adaptation and average MPTh under 20 gF. Differences in responses to thermal and mechanical stimuli for upper verses lower body were consistent with prior research. These findings add to the body of literature confirming that African American adults indeed have lower pain thresholds than those reported for White adults. These QST values can be used as controls for African Americans with cancer to understand the neuropathic pain syndromes associated with tumor progression and cancer treatments.
Citation Format: Keesha L. Powell-Roach, Starja Q. Booker, Yingwei Yao, Marie L. Suarez, Miriam O. Ezenwa, Roger B. Fillingim, Zaijie J. Wang, Robert E. Molokie, Diana J. Wilkie. Age and sex effects on quantitative sensory testing values in healthy African American adults [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D044.