Muscle pain during exercise in normotensive African American women: Effect of parental hypertension history

The purpose of the present investigation was to determine the influence of parental hypertension history on leg muscle pain ratings during cycling exercise in African American women. Eighteen women (age, 19 +/- 2 years) with a positive family history (+PH) of hypertension and 16 (age, 19 +/- 1 years) with a negative family history (-PH) underwent maximal exercise and cold pressor testing. Maximal exercise was conducted on a cycle ergometer. Quadriceps muscle pain intensity ratings were obtained each minute during the maximal exercise test by using a category-ratio scale. The hand cold pressor test was used to determine cardiovascular reactivity. Repeated measures analysis of variance showed significantly lower pain ratings during exercise for the +PH group compared to the -PH group. Psychophysical power functions indicated that the +PH participants had significantly lower exponents for pain throughout exercise. Systolic blood pressure reactivity did not significantly predict pain ratings during exercise. Normotensive African American women with +PH of hypertension experienced less muscle pain during exercise compared to normotensive African American women with a -PH of hypertension. The results are consistent with data demonstrating reduced sensitivity to experimental pain stimuli in individuals at risk for developing hypertension and extend them to naturally occurring muscle pain produced by exercise. Perspective: African American women, a sedentary group with an elevated risk for developing hypertension and chronic pain, show the same negative relationship between +PH and pain perception as men, suggesting that central nervous system mechanisms of pain modulation are more related to family history than gender. Acute exercise provides an experimental model for manipulating naturally occurring pain in studies concerned with the association between pain and hypertension. (C) 2004 by the American Pain Society.