Pressure pain threshold is higher in hypertensive compared with normotensive older adults: A case-control study

Impact of homeostatic body hydration status, evaluated by hemodynamic measures, on different pain sensitization paths to a chronic pain syndrome

Contrasting findings on the mechanisms of chronic pain and hypertension development render the current conventional evidence of a negative relationship between blood pressure (BP) and pain severity insufficient for developing personalized treatments. In this interdisciplinary study, patients with fibromyalgia (FM) exhibiting clinically normal or elevated BP, alongside healthy participants were assessed. Different pain sensitization responses were evaluated using a dynamic 'slowly repeated evoked pain' (SREP) measure, as well as static pain pressure threshold and tolerance measures. Cardiovascular responses to clino-orthostatic (lying-standing) challenges were also examined as acute re- and de-hydration events, challenging cardiovascular and cerebrovascular homeostasis. These challenges involve compensating effects from various cardiac preload or afterload mechanisms associated with different homeostatic body hydration statuses. Additionally, hair cortisol concentration was considered as a factor with an impact on chronic hydration statuses. Pain windup (SREP) and lower pain threshold in FM patients were found to be related to BP rise during clinostatic (lying) rehydration or orthostatic (standing) dehydration events, respectively. These events were determined by acute systemic vasoconstriction (i.e., cardiac afterload response) overcompensating for clinostatic or orthostatic cardiac preload under-responses (low cardiac output or stroke volume). Lower pain tolerance was associated with tonic blood pressure reduction, determined by permanent hypovolemia (low stroke volume) decompensated by permanent systemic vasodilation. In conclusion, the body hydration status profiles assessed by (re)activity of systemic vascular resistance and effective blood volume-related measures can help predict the risk and intensity of different pain sensitization components in chronic pain syndrome, facilitating a more personalized management approach.

EFFECT OF HYPERTENSION ON PAIN THRESHOLD IN PATIENTS WITH CHRONIC PAIN

Introduction: Little is known about the relationship between pain and hypertension (HT). This study aimed to analyze the effect of HT on pain sensitivity in patients with chronic musculoskeletal pain complaints. Methods: This analytical, cross-sectional study included 45 patients aged 29–75 years with HT. The control group comprised 44 normo/hypotensive patients aged 19–66 (P = 0.107). Education status, age, gender, height, weight, smoking, presence of diabetes mellitus, physical activity level, blood pressure measurement, anti-HT drug use, vital parameters, including heart rate, respiratory rate, and body temperature, were recorded for all participants. Results: The pain score was significantly higher in the HT group, with a mean of 72.1 ± 30.2 points (P = 0.008). Also, the HT group’s systolic blood pressure and pain score were significantly positively correlated (rho = 0.245, P = 0.02). The pulse rate was found to be significantly related to the pain score and pain threshold (P < 0.001); it was negatively correlated with algometer values (rho = –0.286, P = 0.015). Systolic pressure (P = 0.033) and BMI ( P < 0.001) were significantly different among the groups according to physical activity level. The Spearman correlation analysis showed a positive correlation of diastolic blood pressure with the body mass index (rho = 0.224, P = 0.036) and pain score (rho = 0.456, P < 0.001).  Conclusion: The present study showed that the pain complaint increases as the blood pressure and weight increase. Also, the pain threshold decreases as the heart rate increases. The pain threshold was lower in women than in men, independent of tension.

Blood pressure-related hypoalgesia: a systematic review and meta-analysis

OBJECTIVE

Spontaneous or experimentally induced high blood pressure (BP) is associated with reduced pain perception, known as BP-related hypoalgesia. Despite its clinical implications, such as the interference with early detection of myocardial infarction in 'at risk' groups, the size of the association between high BP and pain has not yet been quantified. Moreover, the distinct association between high BP and physiological or psychological components of pain has not yet been considered so far. The aim of this study was to overcome this gap by performing separate meta-analyses on nociceptive response versus quantifiable perceptual measures of pain in relation to high BP.

METHODS

PubMed and Web of Knowledge databases were searched for English language studies conducted in humans. Fifty-nine studies were eligible for the analyses. Pooled effect sizes (Hedges' g) were compared. Random effect models were used. Results show that higher BP is significantly associated with lower nociceptive response (g = 0.38; k = 6) and reduced pain perception, assessed by quantifiable measures (g = 0.48; k = 59).

RESULTS

The association between BP and pain perception, derived from highly heterogeneous studies, was characterized by significant publication bias. BP assessment, pain assessment, site of pain stimulation, percentage of female participants in the sample, and control for potential confounders were significant moderators.

CONCLUSION

Current meta-analytic results confirm the presence of BP-related hypoalgesia and point towards the need for a better understanding of its underlying mechanisms.

Impact of antihypertensive treatment on resiliency to clinical pain

OBJECTIVES

Although progress has been made in the regulation of hypertension over the past decades, the USA and some other countries have faced a significant rise in incidence of chronic pain management cases during the same period. Studies of the relationship between pain and blood pressure (BP) regulations propose that these two processes may be interconnected. Studies of effects of antihypertensive treatment on pain in general and its chronification have never been reviewed.

METHODS

A narrative review of respective studies with analysis of credibility of the findings was conducted.

RESULTS

Some studies have suggested that aggressive reduction of high BP may contribute to a return in pain symptoms and may require more aggressive, long-term pain management. Other studies propose that long-term antihypertensive medication could also increase the risk for new cases of chronic pain. Pain initiates a central neuroplastic resetting of the baroreceptor activation accounting for sustained increase of BP with an adaptive 'pain-killing' or maladaptive 'pain-complication' effect associated with pain chronification, and these mechanisms may be moderated by antihypertensive medications. However, different antihypertensive drugs and nondrug treatments may diversely affect pain mechanisms at different stages of treatments.

CONCLUSION

Uncontrollable reduction of high BP in some patients with hypertension could increase the risk for chronic pain incidence and its severity. Practical recommendations in BP control should be reconsidered to take into account patients' chronic pain. Further research is needed of moderation effects of different antihypertensive manipulations on pain to improve pain management in these patients.

Cardiovascular phenotyping for personalized lifestyle treatments of chronic abdominal pain in Irritable Bowel Syndrome: A randomized pilot study

BACKGROUND

Different physical exercise interventions for pain and other related symptoms largely follow non-personalized guidelines and show a high degree of variability in outcome. These interventions are considered to have different pathways toward improvement in autonomic regulation of energy metabolism. The current pilot study was conducted to assess the predictive value of individual cardiovascular (CV) activity markers at rest to predict clinical outcomes for two popular exercise-based interventions (walking and yoga) in patients with Irritable Bowel Syndrome (IBS).

METHODS

Twenty-seven adult participants with IBS were randomly assigned to a 16-biweekly Iyengar yoga or walking program. They completed pre- and post-treatment assessments on IBS symptom severity, affective and somatic complaints, and various measures of resting autonomic function including blood pressure (BP), heart rate and its variability, baroreceptor sensitivity (BRS) to activations and inhibitions with gains of brady- and tachycardiac baro-responses, and BP start points for these spontaneous baroreflexes.

RESULTS

Pretreatment BRS was differentially related to clinical response for the treatment groups. Specifically, a significant decrease in pain severity was found in response to yoga for those participants who had lower resting BRS to activations, but decreased pain severity was associated with higher resting BRS for those in the walking group. The effect was not related to affective symptom relief. Other CV measures showed similar associations with clinical outcomes for both groups.

CONCLUSIONS

The data suggest therefore that CV based phenotypes may be useful in personalizing clinical interventions for IBS. They may also point to autonomic mechanisms that are targets for such interventions.

Resting blood pressure modulates chest pain intensity in patients with acute myocardial infarction

Introduction and Objectives

Animal models and human studies show that resting blood pressure (BP) is inversely associated with pain sensitivity. The phenomenon of "hypertension-associated hypoalgesia" was proposed as a possible explanation for the intervariability in pain perception. Given that a portion of patients with acute myocardial infarction (AMI) do not experience significant pain, we used the model of severe cardiac ischemia to explore whether BP affects the intensity of chest pain.

Methods

Patients with AMI admitted to the cardiac intensive care unit with coronary catheterization-proven completely occluded coronary artery were included (n = 67). Resting BP at admission and 5 days after AMI was obtained. Participants reported chest pain intensity and underwent psychophysical evaluation including pain ratings for pressure, heat, and pinprick stimuli as well as temporal summation and conditioned pain modulation paradigms.

Results

Patients with lower systolic BP (≤120 mm Hg) vs higher (≥140 mm Hg) reported higher chest pain scores at symptom onset (82.3 vs 61.7, P = 0.048) and during peak AMI (82.8 vs 57.5, P = 0.019). Higher pain ratings in response to pinprick stimulus were associated with lower BP at admission (analysis of variance P = 0.036). Patients with hypertension demonstrated lower pain sensitivity in response to pressure stimulation (531.7 ± 158.9 kPa/s vs 429.1 ± 197.4). No significant associations were observed between BP and the other assessed psychophysical measures.

Conclusion

Study findings reinforce the phenomenon of hypertension-associated hypoalgesia through characterization of the association between BP and clinical pain experiences at onset and during AMI in a model of acute clinical pain.

Three-dimensional scapular kinematics, shoulder outcome measures and quality of life following treatment for breast cancer - A case control study

BACKGROUND

There are no conclusive results concerning changes in scapular kinematics associated with upper limb dysfunctions after breast cancer surgery.

OBJECTIVE

To compare the three-dimensional (3-D) scapular kinematics during elevation of the arm between women after breast cancer surgery and controls. Shoulder range of motion (ROM), muscle strength, pain intensity, upper limb function, and quality of life were also assessed.

METHODS

Forty-two women were assigned to two groups (surgery group, n = 21; control group, n = 21). 3-D scapular kinematics was collected during elevation of the arm in the scapular plane. ROM was assessed using a digital inclinometer, muscle strength using a manual dynamometer, pain with the Visual Analogue Scale (VAS), upper limb function with the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and quality of life with the 36-item Short-Form Health Survey (SF36).

RESULTS

The surgery group presented decreased scapular upward rotation at 120° of arm elevation in the scapular plane (p < .05; d = -0.88), decreased shoulder external rotation ROM and strength of shoulder abduction and external rotation when the affected side was compared to the non-affected side and control group. Moreover, the surgery group also reported higher pain, increased upper limb disability and poorer quality of life compared with healthy controls.

CONCLUSION

Scapular upward rotation seems to be decreased at 120° of arm elevation in women following breast cancer surgery. In addition, shoulder external rotation ROM, abduction strength, external rotation strength, function, and quality of life are also impaired in these women. They also experienced pain during the studied movements.

Quantitative sensory testing in elderly: longitudinal study

ABSTRACT Objective: To evaluate elderly patients in a geriatric service, along with their sensory characteristics and their association with clinical aspects. Methods: This was a descriptive longitudinal study. We enrolled 36 healthy participants of both sexes in this study. The following instruments were used and evaluations performed: clinical evaluation, Mini-Mental State Exam, and quantitative sensory testing. Results: During the follow-up, there was reduction of mean corpuscular volume at each evaluation (p < 0.001) and significant increase in mean corpuscular hemoglobin concentration (p < 0.001). There was an increase of the olfactory (p < 0.001), salty (p = 0.024), sour (p = 0.020), bitter (p = 0.001), facial cold (p = 0.019), hand cold (p = 0.004), facial tactile (p < 0.001), hand tactile (p = 0.012) and facial vibration (p = 0.018) thresholds. Previous existing morbidities were associated with sensitivity changes in the individuals in this sample. Conclusion: This longitudinal study suggests that the loss of sensitivity with aging may be associated with the presence of morbidities in elders.

Prevalence of pruritus in patients with chronic liver disease: A multicenter study

AIM

Pruritus is a common comorbidity in chronic liver disease. The aim of this study was to clarify the prevalence of pruritus and its characteristics in patients with chronic liver disease.

METHODS

A total of 1631 patients with chronic liver disease who attended one of nine joint-research facilities from January to June 2016 were enrolled. We investigated the prevalence of pruritus, itch location, itch duration, daily itch fluctuation, seasonal itch exacerbation, treatment drugs, and therapeutic effects using a medical interview questionnaire.

RESULTS

The median age was 66 years and 890 (54.6%) patients were women. The prevalence of pruritus was 40.3% (658/1631), and it differed according to the underlying liver disease. The most frequent body location for pruritus was on the back (63.1%). Pruritus duration was more than 6 months in 252 (38.3%) patients. The severity of pruritus, assessed using a visual analog scale, was higher during the day than at night (median, 4 vs. 3, P < 0.001). Seasonal exacerbation was observed in 296 (45.0%) patients. Although 301 (45.7%) patients were treated with antipruritic agents, 57.8% (174/301) patients reported an insufficient effect. Active hepatitis B virus infection (odds ratio [OR], 2.51; P = 0.043), primary biliary cholangitis (OR, 3.69; P = 0.018), diabetes (OR, 1.57; P = 0.010), and aspartate aminotransferase ≥60 U/L (OR, 2.06; P = 0.011) were independent factors associated with pruritus.

CONCLUSION

The prevalence of pruritus varies according to the chronic liver disease etiology. Underlying liver disease, aspartate aminotransferase ≥60 U/L, and comorbid diabetes are factors associated with pruritus in patients with chronic liver disease.