Pre-print: Predictors of cold and pressure pain tolerance in healthy South African adults. DOI: 10.1093/pm/pnw291

Abstract: Background: Studies on relationships between sex, ethnicity and pain largely have emanated from the US and Europe. We compared cold (CPT) and pressure pain tolerance (PPT) in male and female South Africans of African and European ancestry and assessed whether psychosocial factors (including pain beliefs) predicted differences in pain tolerance. Methods: We recruited 106 (62 female) students of African ancestry and 106 (55 female) of European ancestry and subjected them to a cold-pressor test and pressure algometry. Socioeconomic status (SES), pain catastrophizing, depression, anxiety and pain beliefs were assessed as predictors of differences in pain tolerance. Results: CPT was lower in students of African compared to European ancestry (for both sexes), and PPT was lower in female than male students (for both ethnicities). Men were less accepting of men expressing pain than were women, with males of African ancestry being least accepting. Multivariate analysis identified that being of African ancestry, and particularly a female of African ancestry predicted lower CPT. Anxiety was of borderline interest. Sex was the only significant predictor of PPT on multivariate analysis (PPT females < males) and catastrophizing was of borderline interest. Female sex and African ancestry were important predictors of acceptance of expression of pain in males. SES was a variable of interest. Conclusions: Despite a different cultural and social background from US and European cohorts, we saw similar patterns of sex and ethnic differences in CPT and PPT in an African cohort. Traditional psychosocial predictors of pain sensitivity were identified as being of interest but were not strongly associated.