RESUMEN
BACKGROUND: Females are at greater risk of chronic pain, and exhibit higher pain sensitivity compared to males. However, sex differences in conditioned pain modulation (CPM), a neurophysiological risk factor of chronic pain, are unclear. CPM is influenced by many factors, some of which are sex-dependent. This study explored the sex differences in CPM and its biobehavioral determinants, such as blood pressure responses, physical activity levels, pain catastrophizing scores, and conditioning stimulus intensity, in young, healthy, physically active males and females. METHODS: Twenty-six males and 24 females completed the CPM test using an electrical pain stimulus and a cold pain stimulus induced via 2 min of cold pressor test. Blood pressure was assessed at baseline and during cold pressor test, whereas cold pain ratings were obtained during cold pressor test to monitor the conditioning stimulus intensity. Physical activity was evaluated via questionnaires and accelerometer, whereas pain catastrophizing was evaluated via a questionnaire. RESULTS: Both males and females exhibited CPM, without sex differences in the magnitude of CPM. The males showed higher resting blood pressure, higher physical activity levels, and lower pain catastrophizing scores than the females, without sex differences observed in cold pain ratings and proportion of those who met the physical activity guidelines. No correlations were observed between CPM and its determinants. CONCLUSIONS: The results suggest the complexity of mechanisms underlying the sex differences in CPM. The sex differences in CPM, along with its determinants, may need to be examined in individuals with some risk factors for chronic pain.
Asunto(s)
Dolor Crónico , Hipertensión , Humanos , Adulto , Masculino , Femenino , Umbral del Dolor/fisiología , Caracteres Sexuales , Percepción del Dolor/fisiología , Dimensión del DolorRESUMEN
It is well-documented that adults of racial/ethnic minorities experience pain more frequently and suffer from more severe pain compared to non-Hispanic White (NHW) adults. These observations are consistent with laboratory findings that adults of racial/ethnic minorities show increased sensitivity to laboratory pain stimuli compared to NHW adults. Research generally shows that central pain inhibitory processing, as quantified using conditioned pain modulation (CPM), serves as a risk factor of clinical pain. Currently, racial/ethnic differences in CPM are poorly understood, and research suggests that physical activity (PA) may help understand potential racial/ethnic differences in CPM. However, very little is known regarding CPM in Hispanic compared to NHW adults. Therefore, the present study compared CPM and PA between Hispanic and NHW adults. Twenty-one young, healthy Hispanic and 21 NHW adults completed validated questionnaires to assess PA, pain catastrophizing, and dispositional optimism. The participants then completed the CPM test to quantify changes in pain ratings to electrical stimuli delivered to the ankle during concurrent application of pressure pain applied to the finger compared to baseline. Results indicated that Hispanic and NHW adults exhibited comparable CPM responses and PA levels, along with similar levels of pain catastrophizing and dispositional optimism (p > 0.05). These results suggest that young, healthy Hispanic and NHW adults may possess a similar risk of clinical pain when they are comparable in PA, pain catastrophizing, and dispositional optimism. More research is needed to explore the role of PA in racial/ethnic disparities in clinical pain and central pain inhibitory processing.