A Comparison of the Thermal and Pressure Pain Thresholds of Arab and Western European Healthy Male Subjects

Summary Background and objective: Pain is a universal experience, personal and subjective. Many factors are involved in the interpretation of this unpleasant feeling, as past experience, ethnicity and culture. Understanding these factors play an important role in a holistic and multidimensional assessment and management of acute and chronic pain. The aim of this study is to determine the differences in experimental pain perception between Arab and western European healthy male subjects. Methods: Fifty-six healthy volunteers Arab and Western European men of Queen Margaret University College to discuss hiring the pain threshold using the method of quantitative limits on the sensory tests (TSA 2001) and a dolorimeter. Thermal and pain threshold to pressure was measured in the thenar eminence of the nondominant hand. Both ethnic groups were analyzed separately. Results: Fifty-six subjects total (28 Arab and 28 European) subjects completed the study. In T-dependent test result indicates no statistically significant difference between the Arabs and Europeans hot [t (54) = 1. 150, p > 0. 05], cold [t (54) = 0. 568, p > 0. 05], and the pressure [t (54) =- 0. 279, p > 0. 05] threshold of pain. Conclusion: There was no statistically significant differences in pain thresholds between Arab and western European healthy male subjects was evident. More research is warranted in this field to access the perceptual and psychological aspects associated with pain. Introduction Pain is a subjective experience (France, 1989) and the protective role of life (Turk and Melzack, 1992). A number of factors that can influence the perception of pain, including psychological, sociological and biological. Pain is the most common symptom in people seeking medical help, and is an increasingly important problem worldwide (Strong, 2002). One of the most important factors affecting the perception of pain is culture. Research indicates that sociocultural factors have great influence on pain and it varies in different social situations. Therefore, it is important to study the reactions of pain of maintaining socio-cultural factors in mind (Zborowski, 1952). To evaluate the effect of pain and patients, the normative data necessary for each ethnic group showed normal behavior and the stimulation of pain in the laboratory. Several methods have been used in the past to induce experimental pain in different populations of the cultural background to determine the influence of culture on pain perception of an individual (Bates et al, 1994, Johnson et al, 1999, Woolf et al, 2003, Ibrahim et al, 2003; Rotheram et al, 2000, Zaidi, 1994, Zborowski, 1952, Dunn, 2004). However, the identification of cultural differences was not the main objective of research in many of these studies. Therefore, there is no need for further studies to determine the influence of culture on pain perception in humans. (Janal et al, 1994; Mimi et al, 2002). Culture affects pain perception and response to pain in different ways (Bates et al, 1993). However, to our knowledge, there has been no research to determine the effect of culture factor in the pain threshold in respect of the populations of Western and Arabic. The case study by Chatuverdi et al (1997) portrays the need for this research. In a study of medical practice in south London showed that there is a delay in South Asia being treated for heart disease (Chatuverdi et al 1997). This delay is found that due to lack of recognition of the patient's behavior as appropriate for your illness by doctors to evaluate. In other words, doctors did not know the normal behavior of this group and therefore did not recognize the significance of their symptoms. Cultural diversity is a known risk factor for the treatment of pain under (Kagawa-Singer & Blackhall, L. J, 2001). Therefore, understanding the cultural factor in pain management plays an important role in the success of modern programs of pain management. The areas of ethnicity and the pain seems to have been less well researched pain associated with age and gender. The influence of the latter two variables in the experience of pain has been studies in both healthy subjects and those with pain. Research on ethnicity is mostly limited to chronic pain. Several studies on this subject suggest that there are different components to the pain, but generally focus on the social and behavioral dimensions. Westbrook et al (1984) and Chatuverdi et al (1997) compared pain behavior of the Swedes, Australians, South Asians and Europeans, respectively. Despite using different methodologies and populations, so the observed differences in pain behavior in ethnic groups. Bates (1993, 1994) suggests that attitudes, beliefs and emotional and psychological state of a person playing an important role in the variation in the experience of chronic pain in different ethnic groups. These factors, which affect pain perception, must be found in any assessment of pain and its effect. Regardless of design or methodology used in the various studies, the researchers point to the importance of considering ethnic, if they are the better understanding of patients. Different methods have been used in the past to induce experimental pain. These include the use of ischemic pain (Rosche et al, 1984), pinching pain (Simmonds et al, 1992), mechanical pain (Simmonds et al, 1992, Walsh et al, 1995) and cold pain (Johnson & amp ; Tabasam, 1999). However, the sensitivity and magnitude of stimulus-response is poorly estimated by these methods (Price, 1996). Dolorimeter quantitative sensory testing and was used because they demonstrate the reliability and validity in the assessment of pain thresholds. The study was designed to investigate a limited area of pain perception in a well-defined population, using materials in which the stimulus to provoke a response quantified. Presuppose • The aim of this study is to determine the difference, if any, in thermal and pain thresholds to pressure from Western Europeans and Arabs healthy male population using quantitative sensory testing and dolorimeter. • A second objective was to obtain normative data of healthy male subjects Arab and Western Europe to the threshold of pain. This can be useful for future research. Method: Before the main study was conducted a pilot study to test various determinants of the study design and methodology. The pilot study was conducted one week before the research study to avoid any prior experience, which may cause prejudice to the outcome. Two issues that were involved in the main study were selected. The methodology followed during the pilot study was similar to that used in the research study. The pilot study results were satisfactory and indicates the feasibility of a full research study. After obtaining the approval of the ethics committee of the University, 56 healthy volunteers were recruited from Queen Margaret University College. Not reviewed had a history of major medical problems or chronic painful conditions. Informed consent was obtained from all subjects before heat and pressure threshold measurement was carried out. Heat, cold pain threshold was measured using a thermal sensory testing (Verdugo and Ochoa, 1992). Pain threshold to pressure was measured using a dolorimeter. The device used was a thermal sensory analyzer (TSA-model 2001Medoc Ltd). The quantitative sensory threshold testing device was programmed so that it must meet five alternately hot and cold stimuli to the nondominant hand (the thenar aspect was used) (Yarnitsky et al, 1995, Shy et al, 2003). To improve the reliability of the results of a starting point for Thermodos was set at 32 º C (Yarnitsky & Ochoa, 1991; Hagander et al, 2000). A range of 0 ° C to 50 ° C was used during the study. The rate of temperature change is set to 1 ° C / sec as the stimulus moved away from the baseline (Yarnitsky, 1997). Intrarater reliability to increase the rate of change of temperature gradually increased (Palmer et al, 2000) and a change in temperature of 3 ° C / sec was established as the stimulation returned to baseline of 32 ° C (Yarnitsky, 1997). Data from the sensory feedback of pain threshold levels are automatically recorded on the computer by a simple button press response this topic at the point where it considers that the painful stimulus. The Thermodos Peltier was tied firmly against the thenar eminence using a tourniquet around 20cm long and 2 cm wide (Hagander et al, 2000; Dyck et al, 1993), and to standardize the contact between the surface Thermodos Peltier and the thenar, the band was extended from 2 cm before the attachment to the area of application. The subject was blinded to the purpose of the study and to avoid the effect of optical feedback, subjects were prevented from seeing the monitor display of information. The pressure test was performed five minutes after the quantitative sensory test was conducted to avoid the possibility that false false sensation and reaction. The subjects were informed that would be measured by the pressure threshold and that they feel the pressure induced discomfort. The subjects were also informed that the pressure is applied to the thenar aspect of the nondominant hand, and will increase. They were instructed to say "stop" at the point where I felt pain, the pressure was then are released immediately (Fischer, 1986). The subjects were placed in comfortable seats and were advised to relax before the experiment. The lack of dominant hand and arm resting on the pillow placed on a table (Fischer, 1986). All subjects were ignorant of the purpose of the study and to avoid the illusion of biofeedback were prevented from seeing the pressure scale. The pressure gauge is applied to the thenar eminence of the nondominant hand so it was vertical and 90 ° to the skin surface. To standardize the procedure, the pressure exerted by the dolorimeter increased at a rate of about 1kg/sec yet. This was achieved by counting "one thousand, two thousand" and so on until the subject said, "STOP" at the point of annoyance is unacceptable. Reading the result of dolorimeter were recorded (Fischer, 1986). Statistical methods: All statistical analysis was performed using SPSS version 12. 0 software. Normality assumption for the primary response of the pain scale variable is checked using the Kolmogorov-Smirnov. In-dependent t test was conducted by the differences in pain threshold scores between groups was used when normality is true of the Assumption. Results: Results were obtained separately for pain threshold and for the comparison of age groups. The average age of the two ethnic groups was compared. It was found that the average age was 24 Arabs. 2 years with SD of 3. 3 years, while the mean ± SD of the European Union was 23. 3 ± 1 years. 0 years (Table 1). Minimum Maximum Mean Std Dev. DeviationArab years 20 years 30 years 24. 2 years 3. 3 yearsW. E Age 20 years 30 years 23. 1 year 3. 0 1 yearsTable: descriptive statistics for all ages participating in the study. Kolmogorov-Smirnov test was conducted to test the normality of age distribution (Pallant, 2001). The test result indicates no evidence against the claim that the distribution is normal, a Kolmogorov-Smirnov test for goodness of fit is insignificant: the Kolmogorov-Smirnov Z = 1. 189, p > 0. 05 (Table 2). Media Parameters 56Normal agencies 23. 70Std. Deviation 3. 219Kolmogorov-Smirnov Z 1. 189Asymp. Sig (2-tailed). 118Table 2: Normal distribution of ages participating The result of the independent t-test ages involved is shown that there was no statistically significant differences with a value of p 0. 435 (P > 0. 05) between the two ethnic groups, suggesting a variation on the same could be assumed. The result of the independent t-test for equal means for the ages involved are 0. 116 (P > 0. 05) (Table 2). Levene test for equal variances t-test for Equality of Means of agesF Sig Sig ft (2tailed) 95% confidence interval UpperEqual DifferenceLower variances assumed. 618. 435 1. 209 54. -. 232 682 2. 753Table 3: independent t-test values for equality of means of ages of Arabs and Europeans. Kolmogorov-Smirnov test was conducted to test the distribution of hot and cold and pain thresholds to pressure from Arab and Western European issues. The result of the Kolmogorov-Smirnov Hot pain thresholds was found with a value of 0. 094 in a meaning of 0. 200. The current test result shows that there is no evidence that the distribution of hot pain thresholds in normal distribution (p > 0. 05). The result of the Kolmogorov-Smirnov test for Cold pain thresholds were found with a value of 0. 094 in a meaning of 0. 200. The result of this test shows that there is no evidence that the distribution of cold pain threshold is normally distributed (p > 0. 05). Finally, results for the Kolmogorov-Smirnov test for pressure pain thresholds were found with a value of 0. 153, meaning of 0. 002. The test result shows that the data is not normally distributed, as the p value was less than 0. 05. However, this result may be due to sampling bias in the selection (Pallant, 2001). Thus, the result was treated as normal distributed (Table 5). Kolmogorov-Smirnov DF testStatistic Next Hot Pain Threshold. 094 56. 200 (*) Cold Pain Threshold. 094 56. 200 (*) pain threshold to pressure. 153 56. 002Table 4: test for normality of the data delivered from heat, cold and pain threshold to pressure from both ethnic groups. Using t-test depended on data for hot pain threshold (N = 28), the result was considered significant at P > 0. 05 for a test of tail, indicating a statistically significant difference in heat pain thresholds between Arab and Western European subjects [t (54) = 1. 150, p > 0. 05]. Levene test for equal variances t-test for Equality of Means of heat, cold and pressure pain thresholdsF DF Sig T Sig. (2-tailed) 95% confidence interval DifferenceLower variations UpperHot pain threshold equal -7. 739. 007 1. 150 54. -. 255 6135 2. Pain Threshold 2635Cold equal variances assumed. 995. -. 323 568 54. 572 -3. 4112 1. Pain Threshold 9041Pressure Equal variances not assumed 15. 407. 000. 279 42. 113. -. 782 5349. 7064Table 5: The independent t test result in hot, cold and pain thresholds to pressure from the Arabs and Europeans. On using the t test of data dependent cold pain threshold (N = 28), the result was considered significant at P > 0. 05 level for a test queue, indicating a statistically significant difference in cold pain thresholds between Arab and Western European subjects [t (54) = 0. 568, p > 0. 05]. Finally, with the dependent t-test on data from pain threshold to pressure the two ethnic groups (N = 28), the result turned out to be not significant at P > 0. 05 level for a test queue, indicating a statistically significant difference in pain threshold to pressure from Arab and western European subjects [t (54) =- 0. 279, p > 0. 05] (Table 6). Although the outcome of the independent t-test for hot and cold, and pain thresholds to pressure to show that, statistically, no significant differences between Arab and western European healthy male subjects. However, there were differences in the standard deviation (SD) between ethnic groups. The SD of Europeans hot, cold and pain threshold pressure has shown a greater difference compared with the flight of Arabs, as shown in Table 2. N Minimum Maximum Mean Std Dev. Pain Threshold DeviationArabs Hot 28 40. 0 C º 46. 4 C # 42. 6 C 1. 9 th CW. European Hot Pain Threshold 28 3. 1 C # 47. 8 ° C 43. 4 º C 3. 2nd CArabs Cold Pain Threshold 28 10. 4 C º 23. 8 C º 18. 0 º C 4. 2nd CW. Cold Pain Threshold European 28 11. 0 C º 28. 1 º C 17. 2 º C 5. 5th CArabs pressure pain threshold 28 2. 0lbs 4. 8 kg 3. 4kg 0. 7kgW. European pressure pain threshold 28 2. 1 kg 6. 2kg 3. 4 kg 1. 4kg Table6: The mean and SD of Arab and European hot and cold and pain thresholds to pressure. Discussion: This study could not demonstrate differences in pain perception threshold between Arab and western European healthy male subjects. This is consistent with studies that examine other ethnic groups (Yosipovitch et al, 2004; Dimsdale, 2000; Greenwald, 1991). These studies showed no significant differences in pain perception between ethnic groups. Although there are theories to explain the possible threshold differences between ethnic groups (Johnson et al, 1999; Westbrook et al, 1984; and Chatuverdi et al, 1997) no significant differences were found in this study. These results contrast with other studies showing that there is a difference in pain perception among different ethnic groups (Bates et al, 1993, Elton 1983, Melzack and Wall, 1982; McCaffery, 1999; Zborowski, 1952 Main & Spanswick , 2000; Juarez, 1999; Westbrook, 1984, Chaturvedi et al, 1997, Sheffield, 2000). By comparing the average values of the criteria, Arab issues in this study appears more sensitive to painful stimuli that subjects in western Europe. As Arab issues were of African origin, the result of this study agrees with a study by Edwards et al (1999, 2001), which suggested that African-American subjects showed increased scores unpleasant lower temperatures compared to white Americans, and greater sensitivity to noxious stimuli. An interesting factor to note in this study is that a greater degree of homogeneity shown by Arab issues for hot water and cold pain threshold when compared with the themes of Western Europe. The standard deviations for the subjects of Western Europe for hot, cold and pain threshold to pressure was higher than for Arab affairs. This can be explained by two factors. The first is the origin of the Arab issues: Due to limited availability, are taken from two African countries close cultural and sociological. The themes of Western Europe, however, were selected from a larger group with many sub-groups and a wide variation in cultural backgrounds. Previous studies have shown wide variations in different sub-groups of the same ethnicity (Zborowski, 1950). The second factor was the time of year when the survey was conducted. As it was shortly after the Christmas and New Year, there is the possibility of alcohol intake by subjects of Western Europe is higher than in other seasons (GEML Jürgen Rehm and Gerhard, 2002). Previous studies have shown that alcohol consumption may play a role in the degree of pain perception (Gustafson and Kallima, 1988, Stewart et al, 2005). Greater consistency of the results of the Arab issues could be explained by them is less likely to have consumed alcohol. This study agrees with studies by Johnson et al (1999), Westbrook et al (1984) and Chatuverdi et al (1997), which show the differences between ethnic groups examined and indicate the need to include cultural considerations in acute and chronic pain management. This study agrees with the study by Reed et al (1995), the results suggest that the subject's skin pigmentation levels may play an important role in the perception of pain from the skin of the Arab issues in general more pigmented, and were more sensitive to hot pain stimulation Western European subjects. This study agrees with those of Yosipovitch et al (2004) and Greenwald et al (1991), the results suggest no differences between ethnic groups in the pain threshold. Conclusion: This study demonstrated the threshold of thermal and pressure pain is not affected by ethnicity and culture of the Arabs and Western Europeans. Within ethnic groups, the variability of the subject can be seen. Given that, the limited evidence from this study indicates little or no difference in pain thresholds between ethnic groups. More research to investigate the psychological aspects of pain is justified. References Bates, MS, Edwards, WT, and Anderson, KO 1993, Ethnocultural influences on variation in the perception of chronic pain. vol. 52, no. 1, pp. 101-112. Bates, MS & Rankin-Hill, L. 1994, Control, culture and chronic pain, social sciences and medicine (1982, vol. 39, no. 5, pp. 629-645. Chaturvedi, N., Rai, H., And Ben-Shlomo, Y . 1997, Lay and diagnosis of health seeking behavior of chest pain in south Asians and Europeans, Lancet., vol. 350, no. 9091, pp. 1578-1583. Dimsdale, JE 2000, beset by the past: the influence of ethnicity in health, psychosomatic medicine. vol. 62, no. 2, pp. 161-170. Dunn, KS & Horgan, AL 2004, religious and nonreligious position to meet older adults experience chronic pain Pain management nursing: Official Journal of the American Pain Society Nurses., vol. 5, no. 1, pp. 19-28. Edwards, RR & Fillingim, RB 1999, the differences ethnic responses thermal pain, Psychosomatic Medicine., vol. 61, no. 3, pp. 346-354. Edwards, RR, Doleys, DM, Fillingim, RB and Lowery, D. 2001, ethnic differences in pain tolerance: clinical implications in chronic pain population, psychosomatic medicine., vol. 63, no. 2, pp. 316-323. Fischer, AA 1986, Pressure threshold meter: its use for quantification sensitive points, Archives of Physical Medicine and Rehabilitation. vol. 67, 11., pp. 836-838. S. French, 1989, for pain: some of the psychological and sociological aspects, Physiotherapy, vol. 75 no. 5, pp. 255-260. Greenwald, HP 1991, ethnic differences in pain perception, pain., vol. 44, no. 2, pp. 157-163. Gustafson, R. & Kallman, H. 1988, alcohol and unpleasant stimuli: the clash of calibration and subjective perception of pain and discomfort, perceptual and motor skills., vol. 66, no. 3, pp. 739-742. Hagander, LG, Midani, HA, Kuskowski, MA, and Parry, GJ 2000, Quantitative sensory testing: effect of site and skin temperature on thermal thresholds, Clinical Neurophysiology, vol. 111, no. 1, pp. 17-22. Ibrahim SA, Burant CJ, Mercer MB, Siminoff, LA, & Kwoh, CK 2003, the old perceptions of the chronic patients the quality of the differences in knee or hip pain: by ethnicity and relationship with clinical variables , life sciences and medical sciences., vol. 58, no 5, pp. M472-M477. Juarez G., Ferrell, B., & Borneman, T. 1999, cultural considerations in education for cancer pain management, education Journal of Cancer, vol. 14, no. 3, pp. 168-173. G Rehm J. & Gerhard, 2002. Average volume of alcohol consumption, consumption habits and mortality among young Europeans in 1999. Addiction 97 [1], 105. Kagawa-Singer M, Blackhall LJ, 2001. Negotiating cross-cultural issues in end of life. JAMA. 286:2993-3001. Janal M. N,. Glusman M,. Kuhl JP, Clark C & W. 1994, the lack of correlation between responses to noxious heat, cold, electrical stimulation and ischemic pain, vol. 58, no. 3, pp. 403-411. Palmer ST, Martin, DJ, Stedman, WM, and Ravey, J. 2000, C and a delta fiber mediated thermal perception: response to temperature change rate using the method of limits, somatosensory and motor research. vol. 17, no. 4, pp. 325-333. Roche PA, Gijsbers K, Belch, JJ, & Forbes, CD 1984, Modification of ischemic pain induced by transcutaneous electrical nerve stimulation, pain. vol. 20, no. 1, pp. 45-52. Rotheram-Boro, MJ 2000, variations in pain perception associated with emotional distress and social identity in AIDS , care of a patient with AIDS and STDs. vol. 14, no. 12, pp. 659-665. Sheffield, D., Krittayaphong, R. Go BM, Christy CG, Biles, PL, and Sheps, DS 1997, the relationship between resting systolic blood pressure and cutaneous pain perception in cardiac patients with angina pectoris and controls pain., vol. 71, no. 3, pp. 249-255. Sheffield, D ., Biles, PL, Orom, H., Maixner, W., & Sheps, DS 2000, race and sex differences in cutaneous pain perception, psychosomatic medicine., vol 62., no. 4, pp. 517-523. Shy ME, Frohman EM, So YT, Arezzo JC, Cornblath DR, Giuliani MJ, Kincaid JC, Ochoa JL, Parry, GJ, and Weimer, LH 2003, quantitative sensory testing: report of the therapeutic and Technology Assessment Subcommittee of the American Academy of Neurology, Neurology., vol. 60, no. 6, pp. 898-904. Simmonds, J. & Blake, R. 1992, stress levels in nursing education, nurse manager. vol. 12, no. 3, pp. 16-19. Stewart, SH, Finn, PR, Phil, RO A dose-response study of the effects of alcohol on the the perception of pain and discomfort due to electric shock in men at high genetic risk families with alcoholism, Berl, vol. 119, no. 3, pp. 261-267. J. Strong, Unruch, A., Wrigh , G. and Barber 2002, the pain of a textbook for therapists. Churchill Livingstone, Edinburgh. Tse, MM, Ng, JK, Chung JW, & Wong, TK 2002, the effect of visual stimuli on pain threshold and tolerance, Journal of Clinical Nursing., vol. 11, no. 4, pp. 462-469. Turk DC and Melzack, R. 1992, Handbook of pain assessment. Guilford Press , New York. Verdugo, R. & Ochoa, JL 1992, quantitative somatosensory thermal test. A key method for functional evaluation of small caliber afferent channels, Brain, a journal of neurology. vol. 115, no. Pt . 3, pp. 893-913. Walsh, DM, Foster NE, Baxter, GD, &, Allen, JM 1995, transcutaneous electrical nerve stimulation. Relevance of stimulation parameters to neurophysiological and hypoalgesic effects, the American Journal of Physical Medicine and Rehabilitation / Association of Academic Physiatrists., vol. 74, no. 3, pp. 199-206. Westbrook MT, Nordholm, LA, and McGee, JE 1984, cultural differences in reactions to patient behavior: a comparison of health professionals in Sweden and Australia, Social Science & Medicine, 1982, vol. 19, no. 9, pp. 939-947. Woolf AD Pfleger & B . 2003 the burden of the main conditions Musculoskelet al, Bulletin of the World Health Organization., vol. 81, no. 9, pp. 646-656. Yarnitsky, D., Sprecher, E., Zaslansky, R ., & Hemli, JA 1995, heat pain thresholds: normative data and repeatability, the pain. vol. 60, no. 3, pp. 329-332. Yarnitsky, D. 1997, Quantitative sensory analysis, muscle and nerve. vol. 20, no. 2, pp. 198-204. Zaidi, F. 1994. The maternity care of Muslim women, a modern midwife. vol. 4, no. 3 pp. 8-10. Zborowski, M. 1952, Cultural components in response to pain, Journal of Social Issues 8 (4) (1952): 16-30 No. 4, pp. -30,052. Pallant 2001