Chronic pain-related changes in cardiovascular regulation and impact on comorbid hypertension in a general population: the Tromsø study

Association between pain and incident arrhythmias in 422,654 individuals: evidence from the UK Biobank cohort

AIMS

Pain is associated with cardiovascular disease; however, its association with incident arrhythmias is unclear. We assessed associations between different pain characteristics (pain type, chronic pain, chronic widespread pain [chronic widespread pain], chronic musculoskeletal pain [chronic musculoskeletal pain], and number of chronic pain and chronic musculoskeletal pain sites) and incident cardiac arrhythmias, overall and by subtype.

METHODS

The study included 422,654 UK Biobank participants. Pain was ascertained via a touchscreen questionnaire. The outcomes were incident arrhythmias: all cardiac arrhythmias, atrial fibrillation (AF), other (non-AF) cardiac arrhythmias, bradyarrhythmias, and ventricular arrhythmias. Multivariable Cox-proportional regression was used to investigate the associations.

RESULTS

Over a mean (SD) follow-up of 13.19 (1.96) years, 36,860 (8.72%) participants developed arrhythmia. Compared with those without pain, those with chronic localized pain and chronic widespread pain had increased risk of all cardiac arrhythmias (hazard ratio [HR] 1.13, 95% confidence interval [CI], 1.10-1.17; 1.34, 1.19-1.51), AF (1.09, 1.05-1.14; 1.33, 1.15-1.55), and other cardiac arrhythmias (1.17, 1.12-1.22; 1.41, 1.20-1.66). There was evidence of a dose-relationship between number of chronic pain sites and risk of all cardiac arrhythmias, AF and bradyarrhythmias. Effect estimates were significantly larger among participants aged <60 years than those aged ≥60 years, and larger in women than men.

CONCLUSIONS

Chronic pain was associated with cardiac arrhythmias. Whilst causation cannot be assumed in any observational study, there was evidence of both a temporal relationship and dose-relationship. These findings reinforce the need for pain management approaches that include a broad assessment of individuals' risk factors, wider health status, and appropriate vigilance for emerging conditions.

Exploring the association of metabolic factors and chronic musculoskeletal pain over a period of 10 years - the Doetinchem Cohort Study

OBJECTIVE

To examine (a) the association between metabolic factors and chronic musculoskeletal pain (CMP), (b) metabolic predictors of CMP 10 years later, and (c) the association and evolution of metabolic factors across different CMP trajectory groups.

DESIGN

Data from the longitudinal Doetinchem Cohort Study were used. We used round 4 (2003-2007), with 4519 participants aged 36-75 years, as the baseline for the present study, with follow-up measurements in round 5 (2008-2012), and 6 (2013-2017), including self-reported pain and metabolic factors, which were measured either via self-report or physical assessment. For the three research aims, (a) generalized linear mixed-effects models, (b) binary logistic regression analyses and (c) linear mixed-effects models were used.

RESULTS

(a) Female sex, higher age, presence of diabetes, higher BMI, lower diastolic blood pressure (BP), and elevated cystatin C were significantly associated with CMP in multivariable logistic analyses. (b) Female sex and elevated BMI were predictors of CMP 10 years later. (c) Those pain-free for 10 years had the lowest BMI levels compared to other CMP groups (development, recovery, persistent, and recurrent CMP). BMI was higher in the persistent CMP group than in the development and recovery groups. The pain-free group had higher diastolic BP compared to those in the persistent CMP group. Participants in the persistent CMP group had higher Cystatin C levels than the free, development and recovery CMP groups. Regarding the evolution of metabolic factors over time, BMI, glucose and diastolic BP evolved differently across the CMP trajectory groups.

CONCLUSION

Our findings indicate the importance of metabolic factors, especially BMI, in the onset and progression of CMP. These findings underscore the need to consider metabolic health in the prevention and treatment of CMP. Key Points • Metabolic factors are associated with the presence of chronic musculoskeletal pain. • Female sex and elevated BMI are predictive of musculoskeletal pain (MP) 10 years later. • Metabolic factors evolve differently over time across different pain trajectory groups, with variations in BMI, glucose, and diastolic blood pressure.

The Relationship of Pain Intensity, Perceived Injustice, and Pain Catastrophizing to Heart Rate Variability In Naturally Occurring Acute Pain

OBJECTIVES

Behavioral factors of pain catastrophizing and perceived injustice are associated with pain intensity in chronic pain. Diminished heart rate variability (HRV) is also strongly associated with chronic pain. These factors have been less explored earlier in the pain experience and it is unclear whether they play a role in the transition from acute to chronic pain. The aim of this study was to determine the relationship between pain catastrophizing, perceived injustice, pain intensity, and HRV in naturally occurring acute pain.

MATERIALS AND METHODS

Ninety-seven patients were recruited from local outpatient physical therapy clinics. Seated HRV was captured on 94 patients via Polar chest strap while patients were taking a survey via iPad. In addition to sociodemographic data, the survey included the Pain Catastrophizing Scale (PCS), Injustice Experience Questionnaire (IEQ), and Numeric Pain Rating Scale (NPRS). The natural log of high-frequency power (lnHFP) HRV was used in the statistical analysis.

RESULTS

Multiple linear regression modeling revealed that lower pain catastrophizing, higher perceived injustice, and lower pain intensity were associated with lower HRV, and accounted for 11.4% of the variance in HRV.

DISCUSSION

While greater chronic pain intensity is associated with lower HRV, the relationship is reversed in the setting of acute pain. These findings highlight the need to better understand the unique factors that contribute to lower HRV in the acute phase.

Effects of the WHO analgesic ladder on pain severity, pain interference, and blood pressure control in hypertensive patients with chronic musculoskeletal pain: a cross-sectional study

AIM

This study aimed to investigate the effects of pain management according to the World Health Organization (WHO) analgesic ladder on pain severity, pain interference, and blood pressure (BP) in treated hypertensive patients with chronic musculoskeletal pain.

BACKGROUND

Pain management can affect BP control owing to the proposed mechanism by which persistent pain contributes to increased BP. However, there are inadequate studies investigating the benefit of pain management in controlling both pain and BP in hypertensive patients who have chronic pain.

METHODS

In this cross-sectional study, demographic data and pain characteristics (resting pain score on the numerical pain rating scale, pain severity, and pain interference subscale of the Brief Pain Inventory) were collected via face-to-face interviews. BP was measured thrice on the same day. Data on pain medications taken in the previous 1 month were retrieved from the medical records. Participants were categorized into three groups following pain management patterns according to the WHO analgesic ladder: no, partial, and complete treatment. Multivariate logistic regression analysis (MLRA) was used to analyse the association between the variables and uncontrolled BP.

FINDINGS

Among 210 participants, the mean (standard deviation) age was 68 (15.5) years, and 60.47% had uncontrolled BP. The resting pain score, pain severity, and pain interference subscale scores of the complete treatment group were significantly lower than that of the partial treatment group (P = 0.036, 0.026, and 0.044, respectively). The MLRA revealed that pain management patterns were associated with uncontrolled BP (adjusted odds ratio [AOR]: 6.75; 95% confidence interval [CI]: 2.71-16.78; P < 0.001) and resting pain scores (AOR: 1.17; 95% CI: 1.04-1.38; P = 0.048). Our findings suggest that pain management patterns adhering to the WHO analgesic ladder can reduce pain severity and pain interference and also control BP in hypertensive patients with chronic musculoskeletal pain.

Chronic pain in multiple sites is associated with cardiovascular dysfunction: an observational UK Biobank cohort study

BACKGROUND

Chronic pain is associated with development of cardiovascular disease. We investigated the association between how widespread chronic pain is and the development of cardiovascular dysfunction.

METHODS

We analysed data from participants enrolled in the UK Biobank study who underwent examinations at baseline, plus first follow-up and two imaging visits. Pain sites (including hip, knee, back, neck/shoulder, or 'all over the body') and pain duration were recorded at each visit. Chronic pain was defined as pain lasting for ≥3 months. Participants were categorised into six groups: no chronic pain, chronic pain in one, two, three, or four sites, or 'all over the body'. Arterial stiffness index was measured at each time point. Carotid intima-media thickness, cardiac index, and left ventricular ejection fraction (LVEF) were measured using ultrasound and heart MRI at two additional imaging visits in a subset of participants. Mixed-effect linear regression models were used for the analyses.

RESULTS

The number of chronic pain sites was directly related to increased arterial stiffness index (n=159,360; β=0.06 per one site increase, 95% confidence interval 0.04 to 0.08). In 23,899 participants, lower LVEF was associated with widespread chronic pain (β=-0.17 per one site increase, 95% confidence interval -0.27 to -0.07). The number of chronic pain sites was not associated with carotid intima-media thickness (n=30,628) or cardiac index (n=23,899).

CONCLUSION

A greater number of chronic pain sites is associated with increased arterial stiffness and poorer cardiac function, suggesting that widespread chronic pain is an important contributor to cardiovascular dysfunction.

Association between chronic pain and risk of cardiometabolic multimorbidity: a prospective cohort study

BACKGROUND

Although chronic pain was deleteriously related to single cardiometabolic diseases, the relationship between chronic pain and cardiometabolic multimorbidity remains unclear. The purpose of this study was to investigate the association between chronic pain with the risk of cardiometabolic multimorbidity.

METHODS

A prospective cohort study included 452 818 participants who were free of cardiometabolic multimorbidity at baseline. Chronic pain was assessed in diverse anatomical sites including the head, face, neck/shoulder, stomach/abdominal area, back, hip and knee or 'all over the body'. Participants were classified into six groups according to the amount of chronic pain sites: no chronic pain, chronic pain at one, two, three and four or more sites, and those reporting pain 'all over the body'. Cardiometabolic multimorbidity was defined as the occurrence of at least two cardiometabolic diseases, involving type 2 diabetes, ischaemic heart disease and stroke.

RESULTS

After a median follow-up of 13.7 years, 4445 participants developed cardiometabolic multimorbidity. Compared with individuals without chronic pain, those experiencing chronic pain in four or more sites were associated with a 1.82-fold (HR: 1.82, 95% CI: 1.61, 2.06) higher risk of cardiometabolic multimorbidity. Pain distributed 'all over the body' was associated with a 59% (HR: 1.59, 95% CI: 1.30, 1.93) increased risk of cardiometabolic multimorbidity Additionally, individuals who had chronic pain in both the head and stomach/abdomen showed the highest risk with cardiometabolic multimorbidity (HR: 1.88, 95% CI: 1.60, 2.20).

CONCLUSIONS

Our findings suggested that there was an elevated risk of cardiometabolic multimorbidity associated with an increased amount of chronic pain sites.

Predicting Chronic Pain and Treatment Outcomes Using Machine Learning Models Based on High-dimensional Clinical Data From a Large Retrospective Cohort

PURPOSE

To identify factors and indicators that affect chronic pain and pain relief, and to develop predictive models using machine learning.

METHODS

We analyzed the data of 67,028 outpatient cases and 11,310 valid samples with pain from a large retrospective cohort. We used decision tree, random forest, AdaBoost, neural network, and logistic regression to discover significant indicators and to predict pain and treatment relief.

FINDINGS

The random forest model had the highest accuracy, F1 value, precision, and recall rates for predicting pain relief. The main factors affecting pain and treatment relief included body mass index, blood pressure, age, body temperature, heart rate, pulse, and neutrophil/lymphocyte × platelet ratio. The logistic regression model had high sensitivity and specificity for predicting pain occurrence.

IMPLICATIONS

Machine learning models can be used to analyze the risk factors and predictors of chronic pain and pain relief, and to provide personalized and evidence-based pain management.

To what degree patient-reported symptoms of central sensitization, kinesiophobia, disability, sleep, and life quality associated with 24-h heart rate variability and actigraphy measurements?

OBJECTIVES

Chronic musculoskeletal pain is associated with decreased parasympathetic and increased sympathetic activity in the autonomic nervous system. The objective of this study was to determine the associations between objective measures of heart rate variability (a measure of autonomic nervous system function), actigraphy (a measure of activity and sleep quality), respiration rates, and subjective patient-reported outcome measures (PROMs) of central sensitization, kinesiophobia, disability, the effect of pain on sleep, and life quality.

METHODS

Thirty-eight study subjects were divided into two subgroups, including low symptoms of central sensitization (n = 18) and high symptoms of central sensitization (n = 20), based on patient-reported scores on the Central Sensitization Inventory (CSI). Heart rate variability (HRV) and actigraphy measurements were carried out simultaneously in 24 h measurement during wakefulness and sleep.

RESULTS

A decrease in HRV during the first 2 h of sleep was stronger in the low CSI subgroup compared to the high CSI subgroup. Otherwise, all other HRV and actigraphy parameters and subjective measures of central sensitization, disability, kinesiophobia, the effect of pain on sleep, and quality of life showed only little associations.

DISCUSSION

The high CSI subgroup reported significantly more severe symptoms of disability, kinesiophobia, sleep, and quality of life compared to the low CSI subgroup. However, there were only small and nonsignificant trend in increased sympathetic nervous system activity and poorer sleep quality on the high central sensitization subgroup. Moreover, very little differences in respiratory rates were found between the groups.

Elucidation of the mechanisms of exercise-induced hypoalgesia and pain prolongation due to physical stress and the restriction of movement

Persistent pain signals cause brain dysfunction and can further prolong pain. In addition, the physical restriction of movement (e.g., by a cast) can cause stress and prolong pain. Recently, it has been recognized that exercise therapy including rehabilitation is effective for alleviating chronic pain. On the other hand, physical stress and the restriction of movement can prolong pain. In this review, we discuss the neural circuits involved in the control of pain prolongation and the mechanisms of exercise-induced hypoalgesia (EIH). We also discuss the importance of the mesolimbic dopaminergic network in these phenomena.

Cardiopulmonary baroreceptors modify pain intensity in patients with chronic back pain

Objective

Baroreceptors play a significant role in nociceptive pain. However, the extent to which baroreceptors modulate nociception in patients with chronic pain is unclear. We tested the hypothesis that cardiopulmonary baroreceptor unloading via LBNP would significantly increase pressure pain threshold and habituation to heat pain among patients with chronic back pain.

Methods

Mechanical pressure pain threshold at the upper trapezius (hand-held algometer) and habituation to heat pain at the forearm were performed during sitting and supine position, and during baroreceptor unloading via lower body negative pressure (LBNP) of -10 mmHg in 12 patients with chronic back pain (54 ± 11 years of age). To determine whether pain reduction is normal during LBNP, studies were repeated in 7 young, healthy participants (23 ± 7).

Results

Mechanical pressure pain threshold (P < 0.01) and habituation to heat pain (P = 0.04) were significantly reduced during supine compared with sitting. Conversely, baroreceptor unloading via LBNP significantly increased pressure pain threshold (P = 0.03) and heat pain habituation (P < 0.01) compared with supine. In young healthy controls, pressure pain threshold was similarly affected when comparing sitting and supine (P = 0.01) and during LBNP (P < 0.01), whereas habituation to heat pain was unaltered when comparing sitting and supine (P = 0.93) and during LBNP (P = 0.90). Total peripheral resistance was increased during LBNP (P = 0.01) but not among young, healthy controls (P = 0.71).

Conclusions

The findings demonstrate cardiopulmonary baroreceptor modulation of nociceptive pain in patients with chronic pain. Interestingly, habituation to heat pain appears more readily modified by cardiopulmonary baroreceptors in patients with chronic back pain compared with young, healthy individuals.

Multisite Pain and Myocardial Infarction and Stroke: A Prospective Cohort and Mendelian Randomization Analysis

Background

Whether individuals with multisite pain had a higher risk of cardiovascular diseases is unclear.

Objectives

The purpose of this study was to investigate the longitudinal association of pain in multiple sites with incident myocardial infarction (MI) and stroke, and to disentangle the genetic causality of these associations.

Methods

A total of 281,760 participants (mean age: 56.3 years) who had no MI and stroke at baseline from UK Biobank study were included. Data on pain in the hip, knee, back and neck/shoulder, or 'all over the body' were collected. Chronic pain was defined if pain had lasted for ≥3 months. MI and stroke events were determined from hospital admission records and death registries. Cox regression and 2-sample Mendelian randomization were used for the analyses.

Results

During a median follow-up of 11.9 years, 4,854 had a first MI and 2,827 had a first stroke. In multivariable analyses, greater number of painful sites was dose-responsively associated with higher risks of incident MI and stroke, with a higher risk among participants with pain 'all over the body' (MI: HR: 1.65, 95% CI: 1.32-2.07; stroke: HR: 1.44, 95% CI: 1.13-1.85). Similar trends and associations were observed in those with chronic pain. Two-sample Mendelian randomization results supported a causal effect of multisite pain on MI risk, but not vice versa. No causal association was found between multisite pain and stroke risk.

Conclusions

Pain in multiple sites causally increases the risk of MI, highlighting that pain should be considered when assessing individuals' MI risk, and pain treatment and management may prevent MI risk.

Conscious connected breathing with breath retention intervention in adults with chronic low back pain: protocol for a randomized controlled pilot study

BACKGROUND

Chronic pain is a major source of human suffering, and chronic low back pain (cLBP) is among the most prevalent, costly, and disabling of pain conditions. Due to the significant personal and societal burden and the complex and recurring nature of cLBP, self-management approaches that can be practiced at home are highly relevant to develop and test. The respiratory system is one of the most integrated systems of the body, and breathing is bidirectionally related with stress, emotion, and pain. Thus, the widespread physiological and psychological impact of breathing practices and breathwork interventions hold substantial promise as possible self-management strategies for chronic pain. The primary aim of the current randomized pilot study is to test the feasibility and acceptability of a conscious connected breathing with breath retention intervention compared to a sham control condition.

METHODS

The rationale and procedures for testing a 5-day conscious connected breathing with breath retention intervention, compared to a deep breathing sham control intervention, in 24 adults (18-65 years) with cLBP is described. Both interventions will be delivered using standardized audio recordings and practiced over 5 days (two times in-person and three times at-home), and both are described as Breathing and Attention Training to reduce possible expectancy and placebo effects common in pain research. The primary outcomes for this study are feasibility and acceptability. Feasibility will be evaluated by determining rates of participant recruitment, adherence, retention, and study assessment completion, and acceptability will be evaluated by assessing participants' satisfaction and helpfulness of the intervention. We will also measure other clinical pain, psychological, behavioral, and physiological variables that are planned to be included in a follow-up randomized controlled trial.

DISCUSSION

This will be the first study to examine the effects of a conscious connected breathing with breath retention intervention for individuals with chronic pain. The successful completion of this smaller-scale pilot study will provide data regarding the feasibility and acceptability to conduct a subsequent trial testing the efficacy of this breathing self-management practice for adults with cLBP.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier NCT04740710 . Registered on 5 February 2021.

Risk factors for failed back surgery syndrome following open posterior lumbar surgery for degenerative lumbar disease

BACKGROUND

With the growing number of traditional posterior open surgery, the incidence of failed back surgery syndrome (FBSS) increases gradually. We aimed to investigate the incidence and risk factors for FBSS following open posterior lumbar surgery for degenerative lumbar disease (DLD).

METHOD

A multivariable regression analysis was performed for 333 consecutive patients to identify potential risk factors for FBSS. Clinical outcomes were evaluated by the validated North American Spine Society (NASS) Questionnaire and numerical rating scale (NRS) for pain. Demographics, diagnostic characteristics, surgical data, radiographic parameters for each patient were analyzed.

RESULT

16.8% of the included patients were classified as FBSS. Univariate analysis showed that age, hypertension, symptom location, intermittent claudication, preoperative pain NRS-leg, HIZ, Modic changes (MCs), surgical strategy and postoperative rehabilitation were related to FBSS. Multivariable logistic regression analysis demonstrated that preoperative NRS-leg (OR:0.80, 95%CI:0.71-0.91, P = 0.001), hypertension (OR: 2.22, 95%CI: 1.10-4.51, P = 0.027), intermittent claudication with waking distance > 100 m (OR: 4.07, 95%CI: 1.75-9.47, P = 0.001) and waking distance ≤ 100 m (OR: 12.43, 95%CI: 5.54-27.92, P < 0.001), HIZ (OR: 8.26, 95%CI: 4.00-17.04, P < 0.001), MCs (OR: 3.41, 95%CI: 1.73-6.71, P < 0.001), postoperative rehabilitation (OR: 2.63, 95%CI: 1.13-6.12, P = 0.024) were risk factors for FBSS.

CONCLUSION

Open posterior lumbar surgery is an effective treatment for DLD which provides pain reduction and lumbar curve improvement with a considerable satisfaction rate. Lower preoperative NRS-leg, hypertension, intermittent claudication, HIZ, MCs and postoperative rehabilitation are risk factors for FBSS, which can serve as a tool for clinicians to identify at-risk population and provide more effective management to mitigate the doctor-patient contradictions and further occupation of medical resources.

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.

Prefrontally modulated vagal neuroimmunomodulation is associated with telomere length

Background

Accumulated senescent cells are proposed to be one of the main drivers of age-related pathology such as dementia and cancer through disruption of tissue structure and function. We recently proposed the Neuro-Immuno-Senescence Integrative Model (NISIM), which relates prefrontally modulated vagal tone and subsequent balance between vagal and sympathetic input to the spleen to inflammatory responses leading to generation of reactive oxygen species and oxidative telomere damage.

Aim

In this study, we assess inflammation as a mediator in the relationship between prefrontally modulated vagal tone and leukocyte telomere length (LTL). We also assess the relationship between a recently proposed index of vagal neuroimmunomodulation (vagal tone/inflammation ratio; NIM index) and telomere length.

Methods

This study uses participant data from a large nationally representative longitudinal study since 1974 with a total of 45,000 Norwegian residents so far. A sub-sample of 131 participants from which ultrashort recordings (30 s) of vagal tone, c reactive protein, and LTL could be obtained were included in the study. Relationships were analyzed with Pearson's correlations and hierarchical multiple linear regression using either vagal tone and CRP or the NIM index to predict telomere length.

Results

Vagal tone was a significant positive predictor of telomere length but this was not mediated by c reactive protein, even after controlling for confounders. The NIM index was a significant positive predictor of telomere length, also when controlling for confounders. In a follow-up analysis simultaneously comparing telomere length between groups with high and low values of vagal tone, and between groups with high and low NIM index values, telomere length was only significantly different between NIM index groups.

Conclusion

This is the first study suggesting that prefrontally modulated vagal neuroimmunomodulation is associated with telomere length thus supporting the NISIM. Results indicate that the NIM index is a more sensitive indicator of vagal neuroimmunomodulation than vagal tone and CRP in isolation.

The association between short-term, chronic localized and chronic widespread pain and risk for cardiovascular disease in the UK Biobank

AIMS

The interplay between pain of different chronicity and cardiovascular disease (CVD) is incompletely understood. We aimed to investigate the association between different levels of chronic or nonchronic pain and risk of CVD.

METHODS AND RESULTS

Participants in the UK Biobank who reported pain at baseline were divided into three groups according to pain duration and widespreadness. Participants reporting no pain were controls. Multivariable Cox regression was used to investigate the association between pain and incidence of myocardial infarction, heart failure, stroke, cardiovascular mortality, and composite CVD (defined as any of the before-mentioned cardiovascular events). Of 475 171 participants, 189 289 reported no pain, 87 830 reported short-term pain, 191 716 chronic localized pain, and 6336 chronic widespread pain (CWP). During a median of 7.0 years' follow-up, participants with chronic localized pain and CWP had, after adjustment for age, sex, established cardiovascular risk factors, physical activity, anxiety, depression, cancer, chronic inflammatory/painful disease, pain/anti-inflammatory medication, socioeconomic status, a significantly increased risk for composite CVD [hazard ratio (HR) 1.14, confidence interval (CI) 1.08-1.21, P < 0.001; and HR 1.48, CI 1.28-1.73, P < 0.001, respectively] compared with controls, with similar results when using the different specific CVDs as outcomes. Population attributable risk proportion for chronic pain as a risk factor for composite CVD was comparable with that of diabetes (8.6 vs. 7.3%, respectively).

CONCLUSION

Chronic pain is associated with an increased risk for myocardial infarction, stroke, heart failure, and cardiovascular death independent of established cardiovascular risk factors, socioeconomic factors, comorbidities and medication. Our study, the largest to date, confirms and extends our understanding of chronic pain as an underestimated cardiovascular risk factor with important public health implications.

Meditative-based diaphragmatic breathing vs. vagus nerve stimulation in the treatment of fibromyalgia-A randomized controlled trial: Body vs. machine

IMPORTANCE

Vagus nerve innervation via electrical stimulation and meditative-based diaphragmatic breathing may be promising treatment avenues for fibromyalgia.

OBJECTIVE

Explore and compare the treatment effectiveness of active and sham transcutaneous vagus nerve stimulation (tVNS) and meditative-based diaphragmatic breathing (MDB) for fibromyalgia.

DESIGN

Participants enrolled from March 2019-October 2020 and randomly assigned to active tVNS (n = 28), sham tVNS (n = 29), active MDB (n = 29), or sham MDB (n = 30). Treatments were self-delivered at home for 15 min/morning and 15 min/evening for 14 days. Follow-up was at 2 weeks.

SETTING

Outpatient pain clinic in Oslo, Norway.

PARTICIPANTS

116 adults aged 18-65 years with severe fibromyalgia were consecutively enrolled and randomized. 86 participants (74%) had an 80% treatment adherence and 107 (92%) completed the study at 2 weeks; 1 participant dropped out due to adverse effects from active tVNS.

INTERVENTIONS

Active tVNS is placed on the cymba conchae of the left ear; sham tVNS is placed on the left earlobe. Active MDB trains users in nondirective meditation with deep breathing; sham MDB trains users in open-awareness meditation with paced breathing.

MAIN OUTCOMES AND MEASURES

Primary outcome was change from baseline in ultra short-term photoplethysmography-measured cardiac-vagal heart rate variability at 2 weeks. Prior to trial launch, we hypothesized that (1) those randomized to active MDB or active tVNS would display greater increases in heart rate variability compared to those randomized to sham MDB or sham tVNS after 2-weeks; (2) a change in heart rate variability would be correlated with a change in self-reported average pain intensity; and (3) active treatments would outperform sham treatments on all pain-related secondary outcome measures.

RESULTS

No significant across-group changes in heart rate variability were found. Furthermore, no significant correlations were found between changes in heart rate variability and average pain intensity during treatment. Significant across group differences were found for overall FM severity yet were not found for average pain intensity.

CONCLUSIONS AND RELEVANCE

These findings suggest that changes in cardiac-vagal heart rate variability when recorded with ultra short-term photoplethysmography in those with fibromyalgia may not be associated with treatment-specific changes in pain intensity. Further research should be conducted to evaluate potential changes in long-term cardiac-vagal heart rate variability in response to noninvasive vagus nerve innervation in those with fibromyalgia.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT03180554, Identifier: NCT03180554.

Headache Disorders: Does Pain Affect Blood Pressure?

PURPOSE OF REVIEW

The perspective that pain corresponds to elevated blood pressure is overly simplistic. Our objective is to investigate and debunk misconceptions regarding the effect of pain on blood pressure.

RECENT FINDINGS

While pain can increase blood pressure in the acute setting, prolonged pain and migraine's effect on blood pressure varies and can result in lower-than-expected blood pressure. Therefore, attributing pain as a sole source of elevation of blood pressure may lead to delays in diagnosing hypertension. Based on limited studies available, comorbid pain and chronic hypertension have a higher concurrence than in the general population. We will review current literature to investigate the effect of pain on blood pressure and prevalence of hypertension in chronic pain sufferers. A better understanding of pain's effect on blood pressure will help practitioners appropriately diagnose and counsel patients without disproportionately attributing high blood pressure to pain.

The Effects of Pain and Analgesic Medications on Blood Pressure

PURPOSE OF REVIEW

To review the blood pressure (BP) effects of pain and analgesic medications and to help interpret BP changes in people suffering from acute or chronic pain.

RECENT FINDINGS

Acute pain evokes a stress response which prompts a transient BP increase. Chronic pain is associated with impaired regulation of cardiovascular and analgesia systems, which may predispose to persistent BP elevation. Also analgesics may have BP effects, which vary according to the drug class considered. Data on paracetamol are controversial, while multiple studies indicate that non-steroidal anti-inflammatory drugs may increase BP, with celecoxib showing a lesser impact. Hypotension has been reported with opioid drugs. Among adjuvants, tricyclic antidepressants and serotonin-norepinephrine reuptake inhibitors could be pro-hypertensive due to potentiation of adrenergic transmission. Pain and analgesics may induce a clinically significant BP destabilization. The implications on hypertension incidence and BP control remain unclear and should be explored in future studies.

Reduced heart rate variability is related to the number of metabolic syndrome components and manifest diabetes in the sixth Tromsø study 2007-2008

Both diabetes mellitus (DM) and the metabolic syndrome (MetS) are associated with autonomic neuropathy, which predisposes to cardiac events and death. Measures of heart rate variability (HRV) can be used to monitor the activity of the autonomic nervous system (ANS), and there are strong indications that HRV can be used to study the progression of ANS-related diabetes complications. This study aims to investigate differences in HRV in healthy, MetS and diabetic populations. Based on 7880 participants from the sixth health survey in Tromsø (Tromsø 6, 2007–2008), we found a significant negative association between the number of MetS components and HRV as estimated from short-term pulse wave signals (PRV). This decrease in PRV did not appear to be linear, instead it leveled off after the third component, with no significant difference in PRV between the MetS and DM populations. There was a significant negative association between HbA1c and PRV, showing a decrease in PRV occurring already within the normal HbA1c range. The MetS and DM populations are different from healthy controls with respect to PRV, indicating impaired ANS in both conditions. In the future, a study with assessment of PRV measurements in relation to prospective cardiovascular events seems justified.

Prevalence of pain in community-dwelling older adults with hypertension in the United States

Hypertension and pain are both prevalent conditions in the older adult population. We aimed to report the prevalence of pain discomforts and investigated the association between hypertension and pain discomforts among older adults in the United States. Data from the 2011 National Health and Aging Trends Study were analyzed. In-person interviews were conducted in 7601 adults ages ≥ 65 years. Prevalence of bothersome pain, activity-limiting pain, locations of pain and usage of pain medicine were evaluated. Demographics, comorbidities, and other covariates were compared between older adults with hypertension and those without. Multivariate regression was further performed to yield adjusted odd ratios. Among 6825 older adults, 4533 of them had a history of hypertension while 2272 of them had not. Prevalence of bothersome pain (57.12% versus 44.81%, p < 0.001) and activity-limiting pain (56.21% versus 46.12%, p < 0.001) were significantly higher in the hypertension group. After adjusting for all covariates, hypertension demonstrated a significant association with activity-limiting pain (OR 1.63, 95% CI 1.06 to 2.52, p = 0.02). In conclusion, pain was more prevalent in older Americans with hypertension. The positive association between hypertension and pain suggested that routine pain assessment and proper treatment would be required to improve the function and quality of life among older adults especially with hypertension.

Effect of slow, deep breathing on visceral pain perception and its underlying psychophysiological mechanisms

BACKGROUND

Studies using somatic pain models have shown the hypoalgesic effects of slow, deep breathing. We evaluated the effect of slow, deep breathing on visceral pain and explored putative mediating mechanisms including autonomic and emotional responses.

METHODS

Fifty-seven healthy volunteers (36 females, mean age = 22.0 years) performed controlled, deep breathing at a slow frequency (6 breaths per minute), controlled breathing at a normal frequency (14 breaths per minute; active control), and uncontrolled breathing (no-treatment control) in randomized order. Moderate painful stimuli were given during each condition by delivering electrical stimulation in the distal esophagus. Participants rated pain intensity after each stimulation. Heart rate variability and self-reported arousal were measured during each condition.

KEY RESULTS

Compared to uncontrolled breathing, pain intensity was lower during slow, deep breathing (Cohen's d = 0.40) and normal controlled breathing (d = 0.47), but not different between slow, deep breathing and normal controlled breathing. Arousal was lower (d = 0.53, 0.55) and heart rate variability was higher (d = 0.70, 0.86) during slow, deep breathing compared to the two control conditions. The effect of slow, deep breathing on pain was not mediated by alterations in heart rate variability or arousal but was moderated by pain catastrophizing.

CONCLUSIONS AND INFERENCES

Slow, deep breathing can reduce visceral pain intensity. However, the effect is not specific to the slow breathing frequency and is not mediated by autonomic or emotional responses, suggesting other underlying mechanisms (notably distraction). Whether a long-term practice of slow, deep breathing can influence (clinical) visceral pain warrants to be investigated.

The indirect impact of heart rate variability on cold pressor pain tolerance and intensity through psychological distress in individuals with chronic pain: the Tromsø Study

Supplemental Digital Content is Available in the Text. The hypoalgesic impact of cardiovascular regulatory systems on evoked pain responsiveness in those with chronic pain is conveyed via the indirect effects of psychological distress.

Introduction:

Chronic pain (CP) patients often display lower heart rate variability (HRV) and baroreceptor sensitivity (BRS), which are associated with increased evoked pain intensity and decreased pain tolerance.

Objective:

The purpose of this study was to test whether the association between low levels of HRV and BRS and increased evoked pain responsiveness in individuals with CP is mediated by psychological distress and whether this mediation is sex dependent.

Methods:

The sample consisted of 877 participants in Wave 6 of the Tromsø population study who reported clinically meaningful CP. Resting HRV and BRS parameters were derived from continuous beat-to-beat blood pressure recordings. Psychological distress was assessed using the Hopkins Symptom Checklist-10. After cardiovascular assessment, participants completed a 106-second cold pressor task (3°C bath), which assessed cold pressor pain intensity (CPI) and cold pressor pain tolerance (CPT).

Results:

In the full CP sample, mediation analyses showed significant indirect effects, without direct effects, of HRV and BRS on both CPT and CPI via psychological distress. When stratified by sex, significant indirect effects via psychological distress were only found in males for the impact of rMSSD on CPT, the impact of SDNN on CPT, and the impact of BRS on CPT via psychological distress. Moderated mediation analyses revealed that there were no significant sex differences in the indirect effects of HRV and BRS on both CPT and CPI via psychological distress.

Conclusions:

The hypoalgesic impact of cardiovascular regulatory systems on evoked pain responses is conveyed via the indirect effects of psychological distress.

Procedure-Related Access Site Pain Multimodal Management following Percutaneous Cardiac Intervention: A Randomized Control Trial

Methods

137 patients who underwent PCI procedure via radial artery were randomly assigned (1 : 1) to the control (CG, n = 68) and intervention (IG, n = 65) groups. IG received MPM (paracetamol, ibuprofen, and the arm physiotherapy), CG received pain medication “as needed.” Outcomes were assessed immediately after, 2, 12, 24, and 48 h, 1 week, and 1 and 3 months after PCI. The primary outcome was A-S pain prevalence and pain intensity numeric rating scale (NRS) 0–10.

Results

Results showed that A-S pain prevalence during the 3-month follow-up period was decreasing. Statistically significant difference between the groups (CG versus IG) was after 24 h (41.2% versus 18.5, p=0.005), 48 h (30.9% versus 1.5%, p ≤ 0.001), 1 week (25% versus 10.8%, p=0.042), 1 month (23.5% versus 7.7%, p=0.017) after the procedure. The mean of the highest pain intensity was after 2 h (IG-2.17 ± 2.07; CG-3.53 ± 2.69) and the lowest 3 months (IG-0.02 ± 0.12; CG-0.09 ± 0.45) after the procedure. A-S pain intensity mean scores were statistically significantly higher in CG during the follow-up period (Wilks' λ = 0.84 F (7,125) = 3.37, p=0.002).

Conclusion

In conclusion, MPM approach can reduce A-S pain prevalence and pain intensity after PCI. More randomized control studies are needed.

Web- and Mindfulness-Based Intervention to Prevent Chronic Pain After Cardiac Surgery: Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

Cardiac surgery is a frequently performed procedure. However, pain after cardiac surgery may become chronic (lasting >3 months) in adults. Once discharged from the hospital, patients are at greater risk of developing chronic postsurgical pain (CPSP) and of prolonged opioid use, as they need to self-manage their pain. Psychological risk and protective factors such as pain-related catastrophic thoughts and pain acceptance determine their ability to cope and their use of opioids, which is crucial for self-management of pain. Studies on mindfulness-based cognitive therapy (MBCT) have multiplied their potential effects on pain acceptance and catastrophic thoughts. However, web-based MBCT for the prevention of CPSP has not yet been examined.

OBJECTIVE

The aim of this study is to pilot test a 4-week-long web-based MBCT intervention for adults following discharge from the hospital by assessing the acceptability or feasibility of the intervention and examining preliminary effects on pain intensity, pain interference with activities and opioid use, and pain acceptance and catastrophic thoughts in the 6 months following surgery.

METHODS

A double-blinded pilot randomized controlled trial will be used to assess a web-based MBCT intervention. Patients will be selected according to the following criteria: age ≥18 years; first-time elective cardiac surgery via a median sternotomy; worst pain in the past week score ≥4/10; ability to understand and complete questionnaires in English; and ability to use an electronic device such as a smartphone, computer, or tablet. After baseline measures, 32 participants will be randomized into two groups: one receiving both the brief, 4-week-long web-based MBCT intervention and usual care (experimental group) and the other receiving only one standardized, web-based educational session with weekly reminders and usual care (attention control group). Peer-reviewed competitive funding was received from Florida State University's Council on Research & Creativity in January 2021, as well as research ethics approval from Florida State University's institutional review board.

RESULTS

Recruitment began in June 2021. Unfortunately, because of the current COVID-19 pandemic, recruitment is not progressing as expected. Recruitment strategies are constantly monitored and updated according to latest data and restrictions surrounding the pandemic.

CONCLUSIONS

This research is significant because it targets the trajectory of CPSP, a leading cause of disability and opioid misuse. This is the first study to assess MBCT for the prevention of CPSP after cardiac surgery in the recovery phase. This approach is innovative because it promotes self-management of pain through the modulation of individual factors. If successful, the intervention could be expanded to numerous populations at risk of chronic pain.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/30951.

One Session of Spinal Manipulation Improves the Cardiac Autonomic Control in Patients with Musculoskeletal Pain: A Randomized Placebo-Controlled Trial

STUDY DESIGN

Three-arm, parallel, randomized, placebo-controlled, assessor-blinded trial.

OBJECTIVE

To compare the immediate effect of manual therapy at the upper thoracic spine on the cardiovascular autonomic control of patients with musculoskeletal pain.

SUMMARY OF BACKGROUND DATA

Musculoskeletal pain increases the risk of cardiovascular events. Thus, manual therapy applied to the upper thoracic region is likely efficient to improve the cardiac autonomic control.

METHODS

The study included 59 patients with musculoskeletal pain enrolled at an outpatient clinic. Participants were randomly assigned to spinal manipulation (n = 19), myofascial manipulation (n = 20), or placebo (n = 20) administered to the upper thoracic region. Resting heart rate variability provided indexes of the cardiac autonomic control, and the blood pressure response to the cold pressor test as a proxy of the sympathetic responsiveness to a stressor stimulus.

RESULTS

Groups were similar for baseline variables except for blood pressure. Two-way repeated-measures one-way analysis of covariance (ANCOVA) revealed that only spinal manipulation induced immediate increase of the square root of the mean squared differences of successive RR intervals (RMSSD), absolute (ms2), and normalized units (n.u.) of the high-frequency power (HF) as compared with pre-intervention evaluation, indicating an improvement in the parasympathetic activity to the heart. Normalized units of low-frequency power (LF) and the LF/HF ratio reduced after the spinal manipulation solely, suggesting a reduction of the sympathetic activity to the heart. There were no significant differences in the blood pressure responsiveness among the three treatments. There were no adverse events.

CONCLUSION

In patients with musculoskeletal pain, spinal manipulation on the upper thoracic spine led to an immediate improvement in the resting cardiac autonomic control without an effect on the blood pressure responsiveness to a sympathoexcitatory stimulus. Myofascial manipulation or placebo did not change cardiovascular autonomic control.Level of Evidence: 2.

Multi-Dimensional Impact of Chronic Low Back Pain among Underserved African American and Latino Older Adults

Chronic low back pain is one of the most common, poorly understood, and potentially disabling chronic pain conditions from which older adults suffer. The existing low back pain research has relied almost exclusively on White/Caucasian participant samples. This study examines the correlates of chronic low back pain among a sample of underserved urban African American and Latino older adults. Controlling for age, gender, race/ethnicity, education, living arrangement, and number of major chronic conditions, associations between low back pain and the following outcome variables are examined: (1) healthcare utilization, (2) health-related quality of life (HR-QoL) and self-rated quality of health; and (3) physical and mental health outcomes.

METHODS

We recruited nine hundred and five (905) African American and Latino older adults from the South Los Angeles community using convenience and snowball sampling. In addition to standard items that measure demographic variables, our survey included validated instruments to document HR-QoL health status, the Short-Form McGill Pain Questionnaire-2, Geriatric Depression Scale, sleep disorder, and healthcare access. Data analysis includes bivariate and 17 independent multivariate models.

RESULTS

Almost 55% and 48% of the Latino and African American older adults who participated in our study reported chronic low back pain. Our data revealed that having low back pain was associated with three categories of outcomes including: (1) a higher level of healthcare utilization measured by (i) physician visits, (ii) emergency department visits, (iii) number of Rx used, (iv) a higher level of medication complexity, (v) a lower level of adherence to medication regimens, and (vi) a lower level of satisfaction with medical care; (2) a lower level of HR-QoL and self-assessment of health measured by (i) physical health QoL, (ii) mental health QoL, and (iii) a lower level of self-rated health; and (3) worse physical and mental health outcomes measured by (i) a higher number of depressive symptoms, (ii) a higher level of pain, (iii) falls, (iv) sleep disorders, (v) and being overweight/obese.

DISCUSSION

Low back pain remains a public health concern and significantly impacts the quality of life, health care utilization, and health outcomes of underserved minority older adults. Multi-faceted and culturally sensitive interventional studies are needed to ensure the timely diagnosis and treatment of low back pain among underserved minority older adults. Many barriers and challenges that affect underserved African American and Latino older adults with low back pain simply cannot be addressed in over-crowded EDs. Our study contributes to and raises the awareness of healthcare providers and health policymakers on the necessity for prevention, early diagnosis, proper medical management, and rehabilitation policies to minimize the burdens associated with chronic low back pain among underserved older African American and Latino patients in an under-resourced community such as South Los Angeles.

Transcutaneous Auricular Vagus Nerve Stimulation Combined With Slow Breathing: Speculations on Potential Applications and Technical Considerations

OBJECTIVES

Transcutaneous auricular vagus nerve stimulation (taVNS) is a relatively novel noninvasive neurostimulation method that is believed to mimic the effects of invasive cervical VNS. It has recently been suggested that the effectiveness of taVNS can be enhanced by combining it with controlled slow breathing. Slow breathing modulates the activity of the vagus nerve and is used in behavioral medicine to decrease psychophysiological arousal. Based on studies that examine the effects of taVNS and slow breathing separately, this article speculates on some of the conditions in which this combination treatment may prove effective. Furthermore, based on findings from studies on the optimization of taVNS and slow breathing, this article provides guidance on how to combine taVNS with slow breathing.

MATERIALS AND METHODS

A nonsystematic review.

RESULTS

Both taVNS and slow breathing are considered promising add-on therapeutic approaches for anxiety and depressive disorders, chronic pain, cardiovascular diseases, and insomnia. Therefore, taVNS combined with slow breathing may produce additive or even synergistic beneficial effects in these conditions. Studies on respiratory-gated taVNS during spontaneous breathing suggest that taVNS should be delivered during expiration. Therefore, this article proposes to use taVNS as a breathing pacer to indicate when and for how long to exhale during slow breathing exercises.

CONCLUSIONS

Combining taVNS with slow breathing seems to be a promising hybrid neurostimulation and behavioral intervention.

Cannabis is associated with blood pressure reduction in older adults - A 24-hours ambulatory blood pressure monitoring study

BACKGROUND

Medical cannabis use is increasing rapidly in the past several years, with older adults being the fastest growing group. Nevertheless, the evidence for cardiovascular safety of cannabis use is scarce. The aim of this study was to assess the effect of cannabis on blood pressure, heart rate, and metabolic parameters in older adults with hypertension.

METHODS

We conducted a prospective study of patients aged 60 years or more with hypertension and a new prescription of cannabis. We have performed the following assessments: 24-hours ambulatory blood pressure monitoring, ECG, blood tests, and anthropometric measurements prior to the initiation of cannabis therapy and 3 months afterward. The primary outcome was change in mean 24-h blood pressure at 3 months.

RESULTS

Twenty-six patients with a mean age of 70.42 ± 5.37 years, 53.8% females completed the study. At 3 months follow-up, the mean 24-hours systolic and diastolic blood pressures were reduced by 5.0 mmHg and 4.5 mmHg, respectively (p<0.001 for both). The nadir for the blood pressure and heart rate was achieved at 3 hours post-administration. The proportion of normal dippers changed from 27.3% before treatment to 45.5% afterward. No significant changes were seen in the different metabolic parameters assessed by blood tests, anthropometric measurements, or ECG exam.

CONCLUSION

amongst older adults with hypertension, cannabis treatment for 3 months was associated with a reduction in 24-hours systolic and diastolic blood pressure values with a nadir at 3 hours after cannabis administration.

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.

Pain Characteristics, Cardiovascular Risk Factors, and Cardiovascular Disease

BACKGROUND

There is unclear evidence that chronic pain may increase the risk of cardiovascular disease (CVD) incidence and mortality. This work evaluated the association between chronic pain, incidence of CVD and changes in CVD risk factors.

METHODS

Cohort of 1091 community-dwelling individuals ≥60years, free from CVD at baseline, followed up for 6 years. Data on psychosocial factors and CVD risk factors was obtained through validated questionnaires and laboratory measurements. A pain scale ranging from 0 (no pain) to 6 (worst pain) was created according to pain frequency, location and intensity.

RESULTS

The cumulative incidence of CVD was 4.2% at 3 years, and 7.7% at 5-years of follow-up. Compared to individuals without pain in the first 3 years (2012-2015), those with maintained scores ≥2 showed a mean reduction of 3.57 (-5.77,-1.37) METs-h/week in recreational physical activity; a 0.38-point (0.04,0.73) increase in psychological distress; and a 1.79 (1.03,3.11) higher odds of poor sleep. These associations held in the second follow-up period, when individuals with maintained pain also worsened their diet quality. A 1-point increase in the pain scale in 2012 was associated with a 1.21 (1.03,1.42) and 1.18 (0.97,1.44) increased CVD incidence in 2015 and 2017, respectively; none of the studied factors mediated this relationship.

CONCLUSIONS

Older adults with chronic pain show important reductions in recreational physical activity and deterioration in mental health, sleep and diet quality, which may well aggravate pain. Future studies should evaluate whether these factors mediate the increased risk of CVD observed in older adults with chronic pain.

Autonomous nervous system regulation of pain in children with cerebral palsy

Aim: Children with cerebral palsy (CP) have increased pain sensitivity and recurrent pain episodes; however, pain is underreported in children with intellectual impairment. Cardiac autonomic regulation is imbalanced in chronic pain conditions and neurological disorders. This study aims at exploring the autonomous nervous system regulation of pain in children with CP compared with typically developing peers (TDP).Method: Heart rate variability (HRV) was recorded during 24 hours in 26 children with CP and 26 TDP, and examined offline at baseline (sleeping, seated rest) and during spontaneous pain events. Pain and fatigue, HRV indices (linear indices on time - IBI, SDNN, RMSSD - and frequency domains - high, low, and very low frequency - and non-linear indices - Hurst coefficient and multiscale entropy) were computed.Results: Children with CP showed comparable HRV during daily conditions and similar reductions after pain events than their TDP, regardless of their level of intellectual impairment. Interpretation: Children with CP have an intact autonomic regulation in acute pain events. HRV could be an accurate pain biomarker in children with CP and intellectual disability.What this paper adds: Autonomic regulation in acute pain is efficient in children with cerebral palsy.Heart rate variability indices can be reliable pain biomarkers in intellectual impairment.

Baroreceptor Modulation of the Cardiovascular System, Pain, Consciousness, and Cognition

Baroreceptors are mechanosensitive elements of the peripheral nervous system that maintain cardiovascular homeostasis by coordinating the responses to external and internal environmental stressors. While it is well known that carotid and cardiopulmonary baroreceptors modulate sympathetic vasomotor and parasympathetic cardiac neural autonomic drive, to avoid excessive fluctuations in vascular tone and maintain intravascular volume, there is increasing recognition that baroreceptors also modulate a wide range of non-cardiovascular physiological responses via projections from the nucleus of the solitary tract to regions of the central nervous system, including the spinal cord. These projections regulate pain perception, sleep, consciousness, and cognition. In this article, we summarize the physiology of baroreceptor pathways and responses to baroreceptor activation with an emphasis on the mechanisms influencing cardiovascular function, pain perception, consciousness, and cognition. Understanding baroreceptor-mediated effects on cardiac and extra-cardiac autonomic activities will further our understanding of the pathophysiology of multiple common clinical conditions, such as chronic pain, disorders of consciousness (e.g., abnormalities in sleep-wake), and cognitive impairment, which may result in the identification and implementation of novel treatment modalities. © 2021 American Physiological Society. Compr Physiol 11:1373-1423, 2021.

Machine learning suggests sleep as a core factor in chronic pain

Patients with chronic pain have complex pain profiles and associated problems. Subgroup analysis can help identify key problems. We used a data-based approach to define pain phenotypes and their most relevant associated problems in 320 patients undergoing tertiary pain management. Unsupervised machine learning analysis of parameters "pain intensity," "number of pain areas," "pain duration," "activity pain interference," and "affective pain interference," implemented as emergent self-organizing maps, identified 3 patient phenotype clusters. Supervised analyses, implemented as different types of decision rules, identified "affective pain interference" and the "number of pain areas" as most relevant for cluster assignment. These appeared 698 and 637 times, respectively, in 1000 cross-validation runs among the most relevant characteristics in an item categorization approach in a computed ABC analysis. Cluster assignment was achieved with a median balanced accuracy of 79.9%, a sensitivity of 74.1%, and a specificity of 87.7%. In addition, among 59 demographic, pain etiology, comorbidity, lifestyle, psychological, and treatment-related variables, sleep problems appeared 638 and 439 times among the most important characteristics in 1000 cross-validation runs where patients were assigned to the 2 extreme pain phenotype clusters. Also important were the parameters "fear of pain," "self-rated poor health," and "systolic blood pressure." Decision trees trained with this information assigned patients to the extreme pain phenotype with an accuracy of 67%. Machine learning suggested sleep problems as key factors in the most difficult pain presentations, therefore deserving priority in the treatment of chronic pain.

The Potential Contribution of Chronic Pain and Common Chronic Pain Conditions to Subsequent Cognitive Decline, New Onset Cognitive Impairment, and Incident Dementia: A Systematic Review and Conceptual Model for Future Research

BACKGROUND

Growing evidence suggests that chronic pain and certain chronic pain conditions may increase risk for cognitive decline and dementia.

OBJECTIVE

In this systematic review, we critically evaluate available evidence regarding the association of chronic pain and specific common chronic pain conditions to subsequent decline in cognitive function, new onset cognitive impairment (CI), and incident Alzheimer's disease and related dementias (ADRD); outline major gaps in the literature; and provide a preliminary conceptual model illustrating potential pathways linking pain to cognitive change.

METHODS

To identify qualifying studies, we searched seven scientific databases and scanned bibliographies of identified articles and relevant review papers. Sixteen studies met our inclusion criteria (2 matched case-control, 10 retrospective cohort, 2 prospective cohort), including 11 regarding the association of osteoarthritis (N = 4), fibromyalgia (N = 1), or headache/migraine (N = 6) to incident ADRD (N = 10) and/or its subtypes (N = 6), and 5 investigating the relation of chronic pain symptoms to subsequent cognitive decline (N = 2), CI (N = 1), and/or ADRD (N = 3).

RESULTS

Studies yielded consistent evidence for a positive association of osteoarthritis and migraines/headaches to incident ADRD; however, findings regarding dementia subtypes were mixed. Emerging evidence also suggests chronic pain symptoms may accelerate cognitive decline and increase risk for memory impairment and ADRD, although findings and measures varied considerably across studies.

CONCLUSION

While existing studies support a link between chronic pain and ADRD risk, conclusions are limited by substantial study heterogeneity, limited investigation of certain pain conditions, and methodological and other concerns characterizing most investigations to date. Additional rigorous, long-term prospective studies are needed to elucidate the effects of chronic pain and specific chronic pain conditions on cognitive decline and conversion to ADRD, and to clarify the influence of potential confounding and mediating factors.

Anxiety, Depression, and Pain: Considerations in the Treatment of Patients with Uncontrolled Hypertension

PURPOSE OF REVIEW

The association between mental health, pain, and treatment-resistant hypertension is an important consideration for treating physicians. We review and discuss the connection between conditions of anxiety, depression, and chronic pain and their effect on uncontrolled hypertension.

RECENT FINDINGS

There is significant co-occurrence of hypertension with anxiety, depression, and chronic pain which may lead to undertreatment of hypertension and undertreatment of the underlying mental health disorder. The association between mental health and hypertension is complex and is modulated by physiologic and environmental factors. Physicians treating patients with hypertension should be cognizant of the role anxiety, depression, and chronic pain play in treatment efficacy and compliance. Patients undergoing treatment should be screened for mental health disorders at treatment initiation and frequently thereafter to ensure optimal overall health and compliance.

The Effects of Body Mass Index on the Use of Patient-Controlled Intravenous Analgesia After Open Gastrointestinal Tumor Surgery: A Retrospective Analysis

Purpose

To investigate the impact of body mass index (BMI) on the analgesic effects and adverse reactions of patient-controlled intravenous analgesia (PCIA).

Methods

From 2017 to 2018, 390 patients undergoing open gastrointestinal surgery were reviewed at West China Hospital, Sichuan University. All used PCIA of sufentanil combined with dexmedetomidine and flurbiprofen axetil. According to their BMIs, they were placed into six groups: group A (BMI < 18.5kg/m², 29), group B (18.5kg/m² ≤ BMI< 22kg/m², 124), group C (22kg/m² ≤ BMI < 24kg/m², 99), group D (24kg/m² ≤ BMI < 26kg/m², 69), group E (26kg/m² ≤ BMI < 28kg/m², 46) and group F (BMI ≥28kg/m², 23). Main data of the perioperative use of analgesics, postoperative visual analogue score (VAS), and adverse reactions were collected.

Results

Twenty-four hours (h) after surgery, patients in group A had a higher resting VAS than the other groups, especially B (p_A-B = 0.011). VAS of patients during activity in group B was lower than those in group C 48 h after surgery (p = 0.013). Compared with groups B to F, group A had a significantly lower incidence of hypertension (p = 0.012) and a significantly higher incidence of vomiting 24 h after surgery (p = 0.009). Binary logistic analysis found that higher age was a risk factor for vomiting 24 h after surgery (OR 1.158, p = 0.045).

Conclusion

Using the same PCIA, patients with BMIs of less than 18.5 kg/m² had worse analgesia on the first day after surgery and were more likely to vomit. Postoperative analgesia and related experiences in patients with BMIs of less than 18.5 kg/m² need to be improved.

Whole-Body Vibration as Antihypertensive Non-Pharmacological Treatment in Hypertensive Individuals with Knee Osteoarthritis: Randomized Cross-Over Trial

(1) Background: Hypertension is a serious medical condition characterized by a persistent increase in blood pressure (BP), which is prevalent in individuals with knee osteoarthritis (KOA). Pharmacological interventions are normally used to treat both hypertension and KOA; however, a more sustainable form of treatment is desirable for these clinical conditions. Whole-body vibration (WBV) exercise has been proposed as a non-pharmacological therapy for reducing both BP and KOA symptomatology. This study aimed to evaluate the antihypertensive effect of WBV in hypertensive individuals with KOA. (2) Methods: Nineteen hypertensive individuals with KOA were randomly allocated to either a control (CG) (n = 9) or a WBV group (WBVG) (n = 10). Subjects in the WBVG were positioned sitting in a chair in front of a vibrating platform (VP) with the feet on the base (peak-to-peak displacement 2.5, 5.0 and 7.5 mm; frequencies 5 to 14 Hz). In the CG, subjects assumed the same position with the VP turned off. The protocols in the CG and WBVG were performed 2 days/week for a total of 5 weeks. (3) Results: No baseline differences (age, anthropometrics, BP parameters and medications) between the groups were found (p > 0.05). WBV exercise reduced systolic BP (SBP: 126.1 ± 2.7 versus 119.1 ± 3.2 mmHg; p = 0.001; post hoc: p = 0.02; F = 23.97) and mean BP (MBP: 82.6 ± 1.8 versus 78.7 ± 1.8, p = 0.001, post hoc: p = 0.02; F = 23.97), while no significant changes were found in diastolic BP (DBP: 68.5 ± 2.2 versus 64.4 ± 2.3; p = 0.11; F = 2.68). (4) Conclusions: WBV might be considered a sustainable therapy for exerting an antihypertensive effect in medicated hypertensive individuals with KOA. This decline in BP might translate to a reduction in pharmacological need, although further studies are necessary to understand the mechanisms underlying the described effect.

Psychophysiological responses to various slow, deep breathing techniques

Deep breathing exercises are commonly used for several health conditions including pain and hypertension. Various techniques are available to practice deep breathing, whereas possible differential psychophysiological effects have not been investigated. We compared four deep breathing techniques and examined outcomes in blood pressure variability, respiratory sinus arrhythmia, baroreflex function, and emotional state. Healthy adult volunteers performed pursed-lips breathing, left and right unilateral nostril breathing, and deep breathing with an inspiratory threshold load (loaded breathing), all at a frequency of 0.1 Hz (i.e., controlled breathing) and for three minutes each. Results showed that blood pressure variability was higher during loaded breathing versus other conditions and higher during pursed-lips breathing versus left and right unilateral nostril breathing. Respiratory sinus arrhythmia was higher during loaded breathing versus other conditions and higher during pursed-lips breathing versus left unilateral nostril breathing. The effect of breathing condition on respiratory sinus arrhythmia was mediated by alterations in blood pressure variability. There was no difference between the breathing conditions in baroreflex sensitivity or effectiveness. Participants rated pursed-lips breathing as more calming and pleasant and with more sense of control (vs. other conditions). Overall, among the four tested deep breathing techniques, loaded breathing was associated with enhanced cardiovascular effects and pursed-lips breathing with better emotional responses, while also enhancing cardiovascular effects (albeit less than loaded breathing). These findings can be informative in applying deep breathing techniques as self-management interventions for health conditions, in which baroreceptors stimulation and autonomic and emotional modulations can be beneficial, such as pain and hypertension.

Risk of Major Adverse Cardiovascular Events Associated with Concomitant Use of Antidepressants and Non-steroidal Anti-inflammatory Drugs: A Retrospective Cohort Study

BACKGROUND

Both antidepressants and non-steroidal anti-inflammatory drugs (NSAIDs) have been reported to affect platelet aggregation, blood pressure and heart rate. Despite the high prevalence of the combined use of antidepressants and NSAIDs, there is limited evidence on the potential risk of major adverse cardiovascular events (MACE) associated with their use.

OBJECTIVE

The objective of this study was to assess the association between concomitant antidepressant and NSAID use and MACE.

METHODS

We conducted a retrospective cohort study using South Korea's nationwide healthcare database. The study cohort was defined as those with new prescriptions for antidepressants and NSAIDs between 2004 and 2015. Exposure was assessed as time varying into four discrete periods: non-use, antidepressant use, NSAID use and concomitant use. Our primary outcome was MACE, a composite of haemorrhagic and thromboembolic events; secondary outcomes were the individual events of MACE. A multivariable Cox proportional hazards model was used to estimate hazards ratios with 95% confidence intervals. We also performed subgroup analyses by class of antidepressant/type of NSAIDs, age and sex.

RESULTS

From 240,982 patients, 235,080, 4393 and 1509 patients were users of NSAIDs, antidepressants or both drugs at cohort entry, respectively. The cohort generated 2.1 million person-years of follow-up with 22,453 events of MACE (incidence rate 1.07 per 100 person-years). Compared with non-use, concomitant use (hazard ratio 1.13, 95% confidence interval 1.01-1.26) and NSAID-only use (1.05, 1.001-1.10) were positively associated with MACE, while antidepressant-only use showed a negative association (0.91, 0.83-0.99). Concomitant use increased the individual risk of haemorrhagic stroke (1.46, 1.06-2.00), ischaemic stroke (1.22, 1.07-1.38) and heart failure (1.19, 1.02-1.38), but showed a protective effect on cardiovascular deaths (0.36, 0.21-0.62). Of the six possible combinations of antidepressants and NSAIDs by their classes, only concomitant use of tricyclic antidepressants and non-selective NSAIDs was positively associated with MACE (1.26, 1.09-1.47). The risk of MACE remained elevated with concomitant use among those aged ≥ 45 years (1.14, 1.01-1.29) and male patients (1.19, 1.01-1.42).

CONCLUSIONS

Concomitant use of antidepressants and NSAIDs moderately elevated the risk of MACE, of which the observed risk appears to be driven by the concomitant use of tricyclic antidepressants and non-selective NSAIDs. Thus, healthcare providers should take precaution when co-prescribing these drugs, weighing the potential benefits and risks associated with their use.

The incidence of persistent postoperative opioid use among U.S. veterans: A national study to identify risk factors

OBJECTIVE

To calculate the incidence and identify the predictors of persistent postoperative opioid use at different postoperative days.

BACKGROUND DATA

A subset of surgical patients continues to use long-term opioids. The importance of the risk factors at different postoperative days is not known.

DESIGN

A historical cohort.

SETTING

Postoperative period.

PATIENTS

Opioid-naive U.S. veterans.

INTERVENTIONS

The surgical group had any one of 19 common invasive procedures. The control group is a 10% random sample. Each control was randomly assigned a surgery date.

MEASUREMENTS

The outcomes were the presence of persistent opioid use as determined by continued filling of prescriptions for opioids on postoperative days 90, 180, 270, and 365.

MAIN RESULTS

A total of 183,430 distinct surgical cases and 1,318,894 controls were identified. 1.0% of the surgical patients were using opioids at 90 days, 0.6% at 180 days, 0.4% at 270 days, and 0.1% at 365 days after the surgery. Surgery was strongly associated with postoperative persistent opioid use at day 90 (OR 3.67, 95% CI, 3.43-3.94, p < 0.001), at day 180 (OR 2.85, 2.67-3.12, p < 0.001), at day 270 (OR 2.63, 2.38-2.91, p < 0.001) and at day 365 (OR 2.11, 1.77-2.51, p < 0.001) compared to non-surgical controls. In risk factor analysis, being male and single were associated with persistent opioid use at earlier time points (90 and 180 days), while hepatitis C and preoperative benzodiazepine use were associated with persistent opioid use at later time points (270 and 365 days).

CONCLUSIONS

Many surgeries or invasive procedures are associated with an increased risk of persistent postoperative opioid use. The postoperative period is dynamic and the risk factors change with time.

Linking Pain Sensation to the Autonomic Nervous System: The Role of the Anterior Cingulate and Periaqueductal Gray Resting-State Networks

There are bi-directional interactions between the autonomic nervous system (ANS) and pain. This is likely underpinned by a substantial overlap between brain areas of the central autonomic network and areas involved in pain processing and modulation. To date, however, relatively little is known about the neuronal substrates of the ANS-pain association. Here, we acquired resting state fMRI scans in 21 healthy subjects at rest and during tonic noxious cold stimulation. As indicators of autonomic function, we examined how heart rate variability (HRV) frequency measures were influenced by tonic noxious stimulation and how these variables related to participants’ pain perception and to brain functional connectivity in regions known to play a role in both ANS regulation and pain perception, namely the right dorsal anterior cingulate cortex (dACC) and periaqueductal gray (PAG). Our findings support a role of the cardiac ANS in brain connectivity during pain, linking functional connections of the dACC and PAG with measurements of low frequency (LF)-HRV. In particular, we identified a three-way relationship between the ANS, cortical brain networks known to underpin pain processing, and participants’ subjectively reported pain experiences. LF-HRV both at rest and during pain correlated with functional connectivity between the seed regions and other cortical areas including the right dorsolateral prefrontal cortex (dlPFC), left anterior insula (AI), and the precuneus. Our findings link cardiovascular autonomic parameters to brain activity changes involved in the elaboration of nociceptive information, thus beginning to elucidate underlying brain mechanisms associated with the reciprocal relationship between autonomic and pain-related systems.

Hypertension prevalence in patients attending tertiary pain management services, a registry-based Australian cohort study

Persistent pain and hypertension often co-occur, and share several biological and lifestyle risk factors. The present study aimed to provide insight into the prevalence of, and factors associated with, hypertension in the largest cohort of patients seeking treatment in 43 tertiary pain clinics in Australia. Adults aged > = 18 years registered to the electronic Persistent Pain Outcomes Collaboration registry between 2013 and 2018 were included if they had persistent non-cancer pain (N = 43,789). Risk Ratios (RRs) compared prevalence of self-reported hypertension with the general and primary care Australian populations, and logistic regression examined factors associated with hypertension. One in four (23.9%) patients had hypertension, which was higher than the Australian adult population (2014–15: RR = 5.86, 95%CI: 5.66, 6.06; 2017–18: RR = 9.40, 95%CI: 9.01, 9.80), and in primary care patients (2011–13: RR = 1.17, 95%CI: 1.15, 1.20). Adjusting for covariates, patients with higher odds of hypertension were older, lived in regions with higher socioeconomic disadvantage, had higher levels of BMI, were born outside the Oceania/Australasia region, and had comorbid arthritis, diabetes, or severe-extremely severe anxiety symptoms. Female patients and those with depression symptoms had lower adjusted odds. Unadjusted analyses showed an association between widespread pain, pain duration, pain severity and interference, and lower pain self-efficacy with hypertension; however, only pain severity remained significant in adjusted analyses. Hypertension was more prevalent in people with persistent pain than in the general community, was associated with more severe pain, and commonly co-occurred with pain-related impairments. Routine hypertension screening and treatment targeting shared mechanisms of hypertension and pain may improve treatment outcomes in the pain clinic setting.

Increased blood pressure during the suggested immobilization test in Restless Legs Syndrome

Objective

To investigate the relationship between sensory discomfort/motor component and cardiovascular autonomic response by continuous beat-to-beat blood pressure monitoring (CBPM) during the suggested immobilization test (SIT) in patients with restless legs syndrome (RLS).

Methods

Thirty-two drug-free patients with primary RLS (10 men; mean age 60.29 ± 10.81 years) and 17 healthy controls (2 men; mean age 58.82 ± 11.86 years) underwent a 1-hour SIT starting at 8 pm with concomitant CBPM to measure the heart rate (HR) and systolic/diastolic blood pressure (SBP, DBP). In all subjects, the presence of sensory discomfort and motor component during the SIT (S-SIT+ and M-SIT+, respectively) was quantified. Mixed regression models were used to compare the SBP, DBP, and HR profiles during the SIT by taking into account the repeated measures (6 time periods of 10 minutes).

Results

In patients with S-SIT+ (n = 17), SBP (p &lt; 0.0001), DBP (p = 0.0007), and HR (p = 0.03) increased during the SIT compared with other patients and controls. Seventeen patients had M-SIT+ (none among healthy controls). Classifying patients in 4 groups in function of the presence/absence of the SIT sensory and motor components revealed that SDB and DBP increased throughout the SIT in patients with S-SIT+, independently of the motor component (p &lt; 0.0001 and p = 0.0008 for SBD; p &lt; 0.0001 and p = 0.01 for DBP in the S-SIT+/M-SIT− and S-SIT+/M-SIT+ groups, respectively).

Conclusion

During the SIT, BP concomitantly increased only in patients with RLS and sensory discomfort, with or without motor component. This highlights the link between evening sensory RLS symptoms, autonomic activation, and potential long-term cardiovascular consequences.

Neuropsychological functions of verbal recall and psychomotor speed significantly affect pain tolerance

Background

Effects from cognitive performance on pain tolerance have been documented, however, sample sizes are small and confounders often overlooked. We aimed to establish that performance on neuropsychological tests was associated with pain tolerance, controlling for salient confounders.

Methods

This was a cross‐sectional study nested within the Tromsø‐6 survey. Neuropsychological test performance and the cold pressor test were investigated in 4,623 participants. Due to significant interaction with age, participants were divided into three age groups (<60, ≥60 to <70 and ≥70 years). Cox proportional hazard models assessed the relationship between neuropsychological tests and cold pressure pain tolerance, using hand‐withdrawal as event. The fully adjusted models controlled for sex, education, BMI, smoking status, exercise, systolic blood pressure, sleep problems and mental distress.

Results

In the adjusted models, participants aged ≥70 years showed a decreased hazard of hand withdrawal of 18% (HR 0.82, 95% CI (0.73, 0.92) per standard deviation on immediate verbal recall, and a decreased hazard of 23% (HR 0.77, 95% CI (0.65, 0.08) per standard deviation on psychomotor speed. Participants aged ≥60 to <70 years had a significant decreased hazard of 11% (HR 0.89, 95% CI (0.80, 0.98) per standard deviation on immediate word recall. In participants aged <60 years, there was a decreased hazard of 14% (HR 0.86 95% CI: 0.76, 0.98), per standard deviation on psychomotor speed.

Conclusion

Better performance on neuropsychological tests increased pain tolerance on the cold pressor test. These exposure effects were present in all age groups.

Significance

This paper describes substantial associations between cognitive functioning and cold pressor tolerance in 4,623 participants. Reduced psychomotor speed and poor verbal recall gave greater odds for hand‐withdrawal on the cold pressor task. The associations were stronger in older participants, indicating an interaction with age.

Motivational Non-directive Resonance Breathing as a Treatment for Chronic Widespread Pain

Chronic widespread pain (CWP) is one of the most difficult pain conditions to treat due to an unknown etiology and a lack of innovative treatment design and effectiveness. Based upon preliminary findings within the fields of motivational psychology, integrative neuroscience, diaphragmatic breathing, and vagal nerve stimulation, we propose a new treatment intervention, motivational non-directive (ND) resonance breathing, as a means of reducing pain and suffering in patients with CWP. Motivational ND resonance breathing provides patients with a noninvasive means of potentially modulating five psychophysiological mechanisms imperative for endogenously treating pain and increasing overall quality of life.

Musculoskeletal pains and cardiovascular autonomic function in the general Northern Finnish population

BACKGROUND

Heart rate variability (HRV) and baroreflex sensitivity (BRS) measurements provide means for the objective assessment of cardiovascular autonomic function. As previous studies have associated chronic pain with abnormal autonomic function, we aimed to characterize the relationship between the number of musculoskeletal pain sites (NPS), pain intensity, and cardiovascular autonomic function among the population-based Northern Finland Birth Cohort 1966.

METHODS

At the age of 46, cohort members self-reported their musculoskeletal pains (enabling the determination of NPS [0-8] and pain intensity [Numerical Rating Scale, NRS, 0-10]) and underwent clinical assessments of cardiovascular autonomic function in seated and standing positions (HRV variables: heart rate [HR] and root mean square of successive differences in beat-to-beat intervals [rMSSD] for the entire cohort; BRS variables: low-frequency systolic blood pressure variability [SBPV] and cross-spectral baroreflex sensitivity [BRS] for those attending the examination in Oulu, Finland). Extensive confounder data were also collected (body mass index, physical activity, smoking, Hopkins Symptom Checklist-25, comorbidities, and medications). The full samples included 4186 and 2031 individuals (HRV and BRS samples, respectively). Three subanalyses focused on individuals with intense and frequent pain, individuals with symptoms of depression and anxiety, and the relationship between pain intensity and autonomic parameters.

RESULTS

Linear regression models showed varying associations between NPS, pain intensity, and cardiovascular autonomic parameters. However, after all adjustments NPS was only associated with one outcome among women (BRS, standing: beta = - 0.015, p = 0.048) and two among men (HR, seated: beta = - 0.902, p = 0.003; HR, standing: beta = - 0.843, p = 0.014). Pain intensity was not associated with any outcome after full adjustments. Significant sex*pain interactions were found in the data.

CONCLUSIONS

Our data suggest that musculoskeletal pain has, at most, a limited independent association with cardiovascular autonomic function. Future studies should carefully account for the potential confounders and sex interactions that this study revealed.

Evaluation of Bloodletting Cupping Therapy in the Management of Hypertension

Background

Bloodletting cupping therapy (Hijama) is a traditional alternative medicine practiced in different cultures. Claims about the therapeutic efficacy of Hijama in hypertension are contradictory. The aim of this project was to determine if Hijama therapy is beneficial in the treatment of patients with hypertension.

Materials and Methods

In this retrospective study, 60 files for patients treated for hypertension, aged 40-60 years and whose systolic blood pressure (SBP) is at least 140mm Hg, were used. The data from 30 patient files were obtained from three licensed Hijama centers (study group), whereas data from the rest of 30 patient files were collected from a hospital (control group). The data from Hijama centers included age, date of Hijama therapy, and blood pressure measured before each Hijama session. Both diastolic blood pressure (DBP) and SBP data were obtained over 3-month period.

Results

The results showed a significant reduction in SBP (P value < 0.01) over three sessions of wet cupping (from 149.2 to 130.8mm Hg), but this was not significant for DBP over three sessions (P = 0.074). The study also found that the mean SBP in the study group was 9.6mm Hg less than that in the control group (130.8 vs. 140.4mm Hg, P = 0.019), whereas there was no significant difference in DBP between the study group and the control group (87.0 vs. 86.0mm Hg, P = 0.75).

Conclusions

Our study shows clear relationship between Hijama and the reduction and control of SBP in patients with hypertension. Therefore, Hijama can be used as an adjunct to conventional therapy, which may allow downtitration of given doses of antihypertensive drugs. The possible association of SBP reduction by Hijama and pain reduction needs an investigation.