Greater cardiovascular reactivity to a cold pressor test is due to higher cold pain perception in Black Africans: the SABPA study Short title: cold pain and cardiovascular regulation Authors and Affiliations

Problem: To evaluate the role of pain perception and pain stimulus components for blood pressure responses to stress in the Black African population. Methods: Cardiovascular regulation of hypertensive Black (n=110) and Caucasian (n=95) Africans was studied during a cold pressor test. Perception of stressfulness of the task which was considered equivalent to a rating of cold pain was assessed on a 7-point Likert scale. Chronic stress level was evaluated by the General Health Questionnaire and the Coping Strategy Indicator was used to assess individual coping behavior. Results: The cold pressor test elicited significant blood pressure elevations with higher relative increases in the Black Africans. The higher blood pressure reactivity in the Blacks was accompanied by a substantially greater cardiac response as compared to the Caucasians. The Black Africans also reported higher chronic stress levels and rated the task as more painful than the Caucasians. A significant interaction was observed for cardiovascular responses with pain perception but not with chronic stress. A significant smaller proportion of Black than Caucasian Africans used both problemand emotionfocussed coping. Conclusions: A steeper rise in heart rate in the Black Africans indicates greater painrelated increments in blood pressure. Ethnic differences in cognitive appraisal of pain may contribute to a higher blood pressure reactivity in Black Africans.