Introduction: Sex makes a difference: experimental and clinical pain responses

The influence of physical activity on pain thresholds in patients with depression and multiple somatoform symptoms

OBJECTIVES

Pain is a common symptom with high occurrence in somatoform syndromes and depressive disorders. Research in this area often focuses on experimental induction of pain and subsequent assessment of pain thresholds, ensuring repeatable stimuli of defined quality. Results on sensitivity to experimental pain in major depression are inconclusive, and data on pain thresholds in multiple somatoform symptoms are scarce. The goals of the present study were to differentiate between groups regarding the pressure pain thresholds, and to investigate the possible influence of physical activity on the pain thresholds in these groups. We postulate that physical fitness and physical activity influence pain thresholds in depression and persons with multiple somatoform symptoms.

METHODS

Thirty-eight persons with major depression, 26 persons with a minimum of 6 to 8 somatoform symptoms (somatoform symptom index 8, SSI-8), and 47 healthy participants participated in the study. Baseline values of pressure pain thresholds assessed at different sites of the body were compared with those after 1 week of increased and 1 week of reduced physical activity.

RESULTS

We used repeated measurement design (MANCOVA) and partial correlations for data analysis. Depressed participants reported lower pain thresholds compared with controls, and persons with SSI-8 showed intermediate thresholds. After 1 week of physical activity, participants reported higher pain thresholds. Men had higher pain thresholds following activity as compared with women. Participants who reported higher general fitness also showed higher pain thresholds. Sensitivity to pressure pain is associated with depression, but not with multiple somatoform symptoms.

DISCUSSION

Short low-graded exercise can have reducing effects on perception of pressure pain. Physical activity level is a relevant covariate when using pressure pain assessment. Reduced general fitness can partially account for lower pain thresholds in depression.

Risk factors and symptoms associated with pain in HIV-infected adults

Studies suggest that people living with HIV (PLWH) experience many unrelieved symptoms. The purpose of this study was to estimate the occurrence of pain in adult PLWH and to determine whether participants with pain differed from those without pain on selected demographic factors, clinical characteristics, symptoms of fatigue, sleep disturbance, anxiety, or depression. The authors conducted a descriptive, comparative, and correlational study of 317 PLWH seen at academic and community clinics in San Francisco. Participants completed a demographic questionnaire, the Memorial Symptom Assessment Scale, the Fatigue Severity Scale, the General Sleep Disturbance Scale, the Profile of Moods State Tension-Anxiety subscale, and the Center for Epidemiological Studies-Depression Scale. Clinical characteristics (i.e., disease and treatment information) were obtained by self-report. A single item on pain from the Memorial Symptom Assessment Scale was used to classify participants into those with and without pain. Pain was highly prevalent (55%) and was associated with immune status (CD4+ T-cell count), race, and sleep disturbance, but not with age, gender, or symptoms of fatigue, depression, or anxiety.

Symptom experience in HIV-infected adults: a function of demographic and clinical characteristics

Personal characteristics that interact with both HIV diagnosis and its medical management can influence symptom experience. Little is known about how symptoms in populations with chronic illness vary by age, sex, or socioeconomic factors. As part of an ongoing prospective longitudinal study, this report describes symptoms experienced by 317 men and women living with HIV/AIDS. Participants were recruited at HIV clinics and community sites in the San Francisco Bay Area. Measures included the most recent CD4 cell count and viral load from the medical record, demographic and treatment variables, and the 32-item Memorial Symptom Assessment Scale to estimate prevalence, severity, and distress of each symptom and global symptom burden. The median number of symptoms was nine, and symptoms experienced by more than half the sample population included lack of energy (65%), drowsiness (57%), difficulty sleeping (56%), and pain (55%). Global symptom burden was unrelated to age or CD4 cell count. Those with an AIDS diagnosis had significantly higher symptom burden scores, as did those currently receiving antiretroviral therapy. African Americans reported fewer symptoms than Caucasians or Mixed/Other race, and women reported more symptom burden after controlling for AIDS diagnosis and race. Because high symptom burden is more likely to precipitate self-care strategies that may potentially be ineffective, strategies for symptom management would be better guided by tailored interventions from health care providers.

[Measuring pressure pain thresholds. Comparison of an electromechanically controlled algometer with established methods]

BACKGROUND

Measurement of the pressure pain threshold and suprathreshold pressure pain sensitivity using a newly developed computer controlled algometer was compared to established methods in this pilot study.

METHODS

The pressure pain threshold was measured in 64 chronic pain patients and 37 healthy volunteers with a manual electronic algometer (Somedic) and the computer controlled Algoforce PA3. Stimulus-response curves with painful stimuli were applied using the Algoforce PA3 and a hydraulic algometer.

RESULTS

Overall means and variance of the pressure pain thresholds for both methods were similar. For low pain thresholds the Algoforce PA3 generally resulted in lower values and for high pain thresholds in higher values. No differences were seen for suprathreshold pain sensitivity. Gender and the presence of chronic pain had no relevant effect on the different methods in both comparisons.

CONCLUSION

For clinical use, the algometers investigated deliver comparable results. For studies requiring high precision with low levels of stimulation the use of the Algoforce PA3 could be considered.

Comparison of pain, cortisol levels, and psychological distress in women undergoing surgical termination of pregnancy under local anaesthesia versus intravenous sedation

BACKGROUND

The weight of evidence suggests that women who freely choose to terminate a pregnancy are unlikely to experience significant mental health risks, however some studies have documented psychological distress in the form of posttraumatic stress disorder and depression in the aftermath of termination. Choice of anaesthetic has been suggested as a determinant of outcome. This study compared the effects of local anaesthesia and intravenous sedation, administered for elective surgical termination, on outcomes of pain, cortisol, and psychological distress.

METHODS

155 women were recruited from a private abortion clinic and state hospital (mean age: 25.4 +/- 6.1 years) and assessed on various symptom domains, using both clinician-administered interviews and self-report measures just prior to termination, immediately post-procedure, and at 1 month and 3 months post-procedure. Morning salivary cortisol assays were collected prior to anaesthesia and termination.

RESULTS

The group who received local anaesthetic demonstrated higher baseline cortisol levels (mean = 4.7 vs 0.2), more dissociative symptoms immediately post-termination (mean = 14.7 vs 7.3), and higher levels of pain before (mean = 4.9 vs 3.0) and during the procedure (mean = 8.0 vs 4.4). However, in the longer-term (1 and 3 months), there were no significant differences in pain, psychological outcomes (PTSD, depression, self-esteem, state anxiety), or disability between the groups. More than 65% of the variance in PTSD symptoms at 3 months could be explained by baseline PTSD symptom severity and disability, and post-termination dissociative symptoms. Of interest was the finding that pre-procedural cortisol levels were positively correlated with PTSD symptoms at both 1 and 3 months.

CONCLUSION

High rates of PTSD characterise women who have undergone surgical abortions (almost one fifth of the sample meet criteria for PTSD), with women who receive local anaesthetic experiencing more severe acute reactions. The choice of anesthetic, however, does not appear to impact on longer-term psychiatric outcomes or functional status.

Eccentric exercise in treatment of Achilles tendinopathy

AIM

Prognosis and treatment of Achilles tendon pain (achillodynia) has been insufficiently studied. The purpose of the present study was to examine the long-term effect of eccentric exercises compared with stretching exercises on patients with achillodynia.

METHODS

Patients with achillodynia for at least 3 months were randomly allocated to one of two exercise regimens. Exercise was performed daily for a 3-month period. Symptom severity was evaluated by tendon tenderness, ultrasonography, a questionnaire on pain and other symptoms, and a global assessment of improvement. Follow-up was performed at time points 3, 6, 9, 12 weeks and 1 year.

RESULTS

Of 53 patients with achillodynia 45 patients were randomized to either eccentric exercises or stretching exercises. Symptoms gradually improved during the 1-year follow-up period and were significantly better assessed by pain and symptoms after 3 weeks and all later visits. However, no significant differences could be observed between the two groups. Women and patients with symptoms from the distal part of the tendon had significantly less improvement.

CONCLUSIONS

Marked improvement in symptoms and findings could be gradually observed in both groups during the 1-year follow-up period. To that extent this is due to effect of both regimens or the spontaneous improvement is unsettled.

Ethnic differences in thermal pain responses: a comparison of South Asian and White British healthy males

The expression and report of pain is influenced by social environment and culture. Previous studies have suggested ethnically determined differences in report of pain threshold, intensity and affect. The influence of ethnic differences between White British and South Asians has remained unexplored. Twenty age-matched, male volunteers in each group underwent evaluation. Cold and warm perception and cold and heat threshold were assessed using an ascending method of limits. Magnitude estimation of pain unpleasantness and pain intensity were investigated with thermal stimuli of 46, 47, 48 and 49 degrees C. Subjects also completed a pain anxiety questionnaire. Data was analysed using t-test, Mann-Whitney and repeated measures analysis of variance as appropriate. There were no differences in cold and warm perception between the two groups. There was a statistically significant difference between the two groups for heat pain threshold (P=0.006) and heat pain intensity demonstrated a significant effect for ethnicity (F=13.84, P=0.001). Although no group differences emerged for cold pain threshold and heat unpleasantness, South Asians demonstrated lower cold pain threshold and reported more unpleasantness at all temperatures but this was not statistically significant. Our study shows that ethnicity plays an important role in heat pain threshold and pain report, South Asian males demonstrated lower pain thresholds and higher pain report when compared with matched White British males. There were no differences in pain anxiety between the two groups and no correlations were identified between pain and pain anxiety Haemodynamic measures and anthropometry did not explain group differences.