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(345) Taste perception related to pain responses among African Americans and non-Hispanic whites
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Social and Cultural Variables (344) The association of ancestry informative markers with experimental pain sensitivity D Herbstman, X Mao, M Shriver, D Herrera, B Rahim-Williams, M Wallace, R Fillingim; University of Florida, Gainesville, FL Among the diverse factors that influence pain perception, it has been well documented that there are differences in the experience of pain across populations. Little work has been done to characterize these differences between human populations on the molecular level. The aim of this study was to use ancestry-informative markers (AIMs) to examine differences in pain experience both within and between population groups. AIMs are the molecular markers with substantially different allele frequencies across populations. Experimental pain measures (heat, cold, pressure, and ischemic) were obtained in 148 participants self-described as either Black/African American (n⫽36), Hispanic White (n⫽48), or non-Hispanic White (n⫽64). We genotyped approximately 100 AIMs to assess individual admixture proportions of the study subjects in terms of West African, European, and Native American populations. We modeled the genetic admixture of individuals using a maximum likelihood method and compared these findings with selfreported “race” group designations. Analysis of variance indicated significant differences in genetic ancestry estimates across self-described ethnic/racial groups, such that non-Hispanic Whites and African Americans showed high levels of European and West African ancestry, respectively. Hispanic White participants were the most genetically diverse group, displaying relatively high degrees of both European and Native American ancestry. Among all the ethnic groups, higher West African and Native American ancestry predicted greater pain sensitivity, while European ancestry was a negative regressor of pain sensitivity. The results of this study indicate that the biogeographical ancestry may help us to characterize the genetic component that contributes to the individual differences in pain sensitivity. We show that genetic ancestry information may be a useful tool in understanding the pain experience, and in the future we may be able to utilize molecular measures of admixture to help elucidate individual differences in pain sensitivity.
Abstracts (346) Investigating pain assessment and treatment disparities: A novel virtual human technology application A Hirsh, S George, R Fillingim, W Perlstein, S Manamalkav, M Robinson; University of Florida, Gainesville, FL Patient demographic characteristics and nonverbal communication displays have been found to influence the assessment and treatment of pain. Numerous methodological limitations of these previous investigations constrain the research questions that could be addressed and the conclusions that have been yielded. The current analogue study employed an innovative research design and novel virtual human technology to investigate disparities in clinical decision making for pain assessment and treatment. Fifty-four currently practicing nurses participated in this study delivered via the Internet. Thirty-two vignettes of virtual patients were presented; each vignette contained a video clip of the patient and clinical summary information describing a post-surgical context. Nurses were asked to make decisions regarding the assessment of pain intensity and unpleasantness, in addition to treatment with nonopioid and opioid medications. The patient demographic cues of sex, race, and age, as well as facial expression of pain, were systematically manipulated across vignettes and hypothesized to influence assessment and treatment ratings. Idiographic and nomothetic statistical analyses were conducted to test these hypotheses. Results indicated that at the idiographic level, sex, race, age, and pain expression cues accounted for significant, unique variance in assessment and treatment policies among many nurse participants. Pain expression was the most prominent cue throughout these policy domains. Within-cue differences emerged at the nomothetic level; the size and consistency of these differences varied across policy domains. The current investigation demonstrates the application of novel virtual human technology to the study of disparities in pain-related decision making. These data indicate that the assessment and treatment of acute post-surgical pain often varies based on virtual human demographic characteristics and facial expressions of pain. Implications of the present findings are discussed in the context of the extant literature. Methodological considerations and future research directions are also discussed.
(345) Taste perception related to pain responses among African Americans and non-Hispanic whites
(347) Diffuse noxious inhibitory controls (DNIC) in African Americans, Asian Americans and non-Hispanic whites
D Herrera, C Campbell, C France, L Bartoshuk, R Fillingim; University of Florida, Gainesville, FL Taste perception is an area of increasing attention, as it has recently been associated with long-term health implications such as alcohol intake and cardiovascular disease. Ethnic variations in taste perception have been observed, generally suggesting a preference for sweet tastes in African American participants. The mechanisms underlying taste preference are unclear, though involvement of the endogenous opioid system has been hypothesized. Limited research has examined this connection, though the extant literature suggests individual differences in pressure pain and cold pressor pain tolerance following ingestion of sweet liquid, thus providing evidence for “palatability-induced antinociception.” Ethnic differences in response to both clinical and experimentally induced pain have been well documented and recent evidence may suggest variability in descending inhibition. In the current study we examined the relationship between taste perception and pain responses associated with endogenous opioid activation, the nociceptive flexion reflex (NFR) and diffuse noxious inhibitory controls (DNIC, using NFR and ischemic arm pain) among healthy African Americans (N⫽22) and nonHispanic whites (N⫽24). Four solutions, salty, sweet, sour, and bitter, were applied to the tongue, intensity of the taste sensation was rated immediately following each swab. No ethnic differences in taste ratings emerged. Significant correlations between taste sensitivity and pain were observed. Ratings of sweet and bitter predicted NFR threshold among whites, with higher taste ratings predicting higher NFR; no such association was evident in African Americans. However, ratings of sweet and bitter predicted DNIC-induced reductions in the NFR reflex in both African Americans and whites, with higher taste ratings predicting greater pain inhibition. One potential explanation for these findings is that perception of taste is mediated in part through brain systems (e.g. endogenous opioids) that also influence pain. Thus, measurement of taste sensitivity may reflect the integrity of those systems. Possible underlying mechanisms and potential clinical implications will be discussed.
C Campbell; Johns Hopkins Medical Institute, Baltimore, MD Considerable evidence indicates that African Americans report greater levels of pain in a variety of clinical conditions and demonstrate increased sensitivity to experimentally induced pain when compared to non-Hispanic whites. A dearth of information exists examining the origins of these differences; however, alterations in endogenous pain regulatory mechanisms have been hypothesized to play a role. Diffuse noxious inhibitory controls (DNIC), or counterirritation, is a phenomenon thought to reflect descending inhibition of pain signals and has recently been utilized as a measure of dysregulation of the pain inhibitory system. The current study assessed DNIC in 40 healthy young adults from three different ethnic groups: African Americans, Asian Americans and non-Hispanic whites. A cold pressor task was used as the conditioning stimulus and was repeated prior to and during pressure pain threshold assessment to the trapezius. The conditioning stimulus significantly increased pressure pain thresholds for the entire group (from M⫽352.6 to M⫽445.8, p ⬍ .001). However, The DNIC condition produced significantly greater increase in threshold among Asian Americans and nonHispanic whites when compared with African Americans (p ⫽ .037). The findings of this study suggest differences in endogenous pain inhibition between African Americans and that of Asian Americans and non-Hispanic whites. These results further suggest that the disparities observed between African American and non-Hispanic white individuals may be a result of more than stress associated with factors relating to globalminority status. Additional research to clarify the mechanisms underlying these effects and potential clinical implications is warranted.
Social and Cultural Variables (344) The association of ancestry informative markers with experimental pain sensitivity D Herbstman, X Mao, M Shriver, D Herrera, B Rahim-Williams, M Wallace, R Fillingim; University of Florida, Gainesville, FL Among the diverse factors that influence pain perception, it has been well documented that there are differences in the experience of pain across populations. Little work has been done to characterize these differences between human populations on the molecular level. The aim of this study was to use ancestry-informative markers (AIMs) to examine differences in pain experience both within and between population groups. AIMs are the molecular markers with substantially different allele frequencies across populations. Experimental pain measures (heat, cold, pressure, and ischemic) were obtained in 148 participants self-described as either Black/African American (n⫽36), Hispanic White (n⫽48), or non-Hispanic White (n⫽64). We genotyped approximately 100 AIMs to assess individual admixture proportions of the study subjects in terms of West African, European, and Native American populations. We modeled the genetic admixture of individuals using a maximum likelihood method and compared these findings with selfreported “race” group designations. Analysis of variance indicated significant differences in genetic ancestry estimates across self-described ethnic/racial groups, such that non-Hispanic Whites and African Americans showed high levels of European and West African ancestry, respectively. Hispanic White participants were the most genetically diverse group, displaying relatively high degrees of both European and Native American ancestry. Among all the ethnic groups, higher West African and Native American ancestry predicted greater pain sensitivity, while European ancestry was a negative regressor of pain sensitivity. The results of this study indicate that the biogeographical ancestry may help us to characterize the genetic component that contributes to the individual differences in pain sensitivity. We show that genetic ancestry information may be a useful tool in understanding the pain experience, and in the future we may be able to utilize molecular measures of admixture to help elucidate individual differences in pain sensitivity.
Abstracts (346) Investigating pain assessment and treatment disparities: A novel virtual human technology application A Hirsh, S George, R Fillingim, W Perlstein, S Manamalkav, M Robinson; University of Florida, Gainesville, FL Patient demographic characteristics and nonverbal communication displays have been found to influence the assessment and treatment of pain. Numerous methodological limitations of these previous investigations constrain the research questions that could be addressed and the conclusions that have been yielded. The current analogue study employed an innovative research design and novel virtual human technology to investigate disparities in clinical decision making for pain assessment and treatment. Fifty-four currently practicing nurses participated in this study delivered via the Internet. Thirty-two vignettes of virtual patients were presented; each vignette contained a video clip of the patient and clinical summary information describing a post-surgical context. Nurses were asked to make decisions regarding the assessment of pain intensity and unpleasantness, in addition to treatment with nonopioid and opioid medications. The patient demographic cues of sex, race, and age, as well as facial expression of pain, were systematically manipulated across vignettes and hypothesized to influence assessment and treatment ratings. Idiographic and nomothetic statistical analyses were conducted to test these hypotheses. Results indicated that at the idiographic level, sex, race, age, and pain expression cues accounted for significant, unique variance in assessment and treatment policies among many nurse participants. Pain expression was the most prominent cue throughout these policy domains. Within-cue differences emerged at the nomothetic level; the size and consistency of these differences varied across policy domains. The current investigation demonstrates the application of novel virtual human technology to the study of disparities in pain-related decision making. These data indicate that the assessment and treatment of acute post-surgical pain often varies based on virtual human demographic characteristics and facial expressions of pain. Implications of the present findings are discussed in the context of the extant literature. Methodological considerations and future research directions are also discussed.
(345) Taste perception related to pain responses among African Americans and non-Hispanic whites
(347) Diffuse noxious inhibitory controls (DNIC) in African Americans, Asian Americans and non-Hispanic whites
D Herrera, C Campbell, C France, L Bartoshuk, R Fillingim; University of Florida, Gainesville, FL Taste perception is an area of increasing attention, as it has recently been associated with long-term health implications such as alcohol intake and cardiovascular disease. Ethnic variations in taste perception have been observed, generally suggesting a preference for sweet tastes in African American participants. The mechanisms underlying taste preference are unclear, though involvement of the endogenous opioid system has been hypothesized. Limited research has examined this connection, though the extant literature suggests individual differences in pressure pain and cold pressor pain tolerance following ingestion of sweet liquid, thus providing evidence for “palatability-induced antinociception.” Ethnic differences in response to both clinical and experimentally induced pain have been well documented and recent evidence may suggest variability in descending inhibition. In the current study we examined the relationship between taste perception and pain responses associated with endogenous opioid activation, the nociceptive flexion reflex (NFR) and diffuse noxious inhibitory controls (DNIC, using NFR and ischemic arm pain) among healthy African Americans (N⫽22) and nonHispanic whites (N⫽24). Four solutions, salty, sweet, sour, and bitter, were applied to the tongue, intensity of the taste sensation was rated immediately following each swab. No ethnic differences in taste ratings emerged. Significant correlations between taste sensitivity and pain were observed. Ratings of sweet and bitter predicted NFR threshold among whites, with higher taste ratings predicting higher NFR; no such association was evident in African Americans. However, ratings of sweet and bitter predicted DNIC-induced reductions in the NFR reflex in both African Americans and whites, with higher taste ratings predicting greater pain inhibition. One potential explanation for these findings is that perception of taste is mediated in part through brain systems (e.g. endogenous opioids) that also influence pain. Thus, measurement of taste sensitivity may reflect the integrity of those systems. Possible underlying mechanisms and potential clinical implications will be discussed.
C Campbell; Johns Hopkins Medical Institute, Baltimore, MD Considerable evidence indicates that African Americans report greater levels of pain in a variety of clinical conditions and demonstrate increased sensitivity to experimentally induced pain when compared to non-Hispanic whites. A dearth of information exists examining the origins of these differences; however, alterations in endogenous pain regulatory mechanisms have been hypothesized to play a role. Diffuse noxious inhibitory controls (DNIC), or counterirritation, is a phenomenon thought to reflect descending inhibition of pain signals and has recently been utilized as a measure of dysregulation of the pain inhibitory system. The current study assessed DNIC in 40 healthy young adults from three different ethnic groups: African Americans, Asian Americans and non-Hispanic whites. A cold pressor task was used as the conditioning stimulus and was repeated prior to and during pressure pain threshold assessment to the trapezius. The conditioning stimulus significantly increased pressure pain thresholds for the entire group (from M⫽352.6 to M⫽445.8, p ⬍ .001). However, The DNIC condition produced significantly greater increase in threshold among Asian Americans and nonHispanic whites when compared with African Americans (p ⫽ .037). The findings of this study suggest differences in endogenous pain inhibition between African Americans and that of Asian Americans and non-Hispanic whites. These results further suggest that the disparities observed between African American and non-Hispanic white individuals may be a result of more than stress associated with factors relating to globalminority status. Additional research to clarify the mechanisms underlying these effects and potential clinical implications is warranted.