Cardiac autonomic impairment and chronotropic incompetence in fibromyalgia

Autonomic responses to aerobic and resistance exercise in patients with chronic musculoskeletal pain: A systematic review

BACKGROUND

It is unknown whether patients with chronic musculoskeletal pain (CMP) show autonomic dysregulation after exercise, and the interventional effects of exercise on the autonomic dysregulation have not been elucidated. The objectives of this study were to reveal acute autonomic responses after aerobic and resistance exercises and the interventional effects of both exercises on autonomic dysregulation in patients with CMP.

METHODS

A systematic search using nine electronic databases was performed based on three key search terms: "chronic musculoskeletal pain," "autonomic nervous system," and "exercise." Data were extracted from measurements of the autonomic nervous system and pain.

RESULTS

We found a total of 1170 articles; 17 were finally included, incorporating 12 observational and five interventional studies. Although a comparator has not been specified, healthy controls were compared to patients with CMP in observational studies. Three of five interventional studies were pre-post study with healthy controls as a comparator or no controls. The other two interventional studies were randomized controlled trial with a different treatment e.g., stretching. There were four good, 10 fair, and three poor-quality articles. The total number of participants was 617, of which 551 were female. There was high heterogeneity among the five disease conditions and nine outcome measures. Following one-time exposure to aerobic and resistance exercises, abnormal autonomic responses (sympathetic activation and parasympathetic withdrawal), which were absent in healthy controls, were observed in patients with CMP. The effects of aerobic and resistance exercise as long-term interventions were unclear since we identified both positive effects and no change in the autonomic activities in patients with CMP.

CONCLUSIONS

This study indicates dysfunctional autonomic responses following one-time exposure to exercise and inconsistent interventional effects in the autonomic activities in patients with CMP. Appropriate therapeutic dose is necessary for studying the management of autonomic regulation and pain after exercise.

Cardiac output and arteriovenous oxygen difference contribute to lower peak oxygen uptake in patients with fibromyalgia

BACKGROUND

Patients with fibromyalgia (FM) exhibit low peak oxygen uptake ([Formula: see text]O_2peak). We aimed to detect the contribution of cardiac output to ([Formula: see text]) and arteriovenous oxygen difference [Formula: see text] to [Formula: see text] from rest to peak exercise in patients with FM.

METHODS

Thirty-five women with FM, aged 23 to 65 years, and 23 healthy controls performed a step incremental cycle ergometer test until volitional fatigue. Alveolar gas exchange and pulmonary ventilation were measured breath-by-breath and adjusted for fat-free body mass (FFM) where appropriate. [Formula: see text] (impedance cardiography) was monitored. [Formula: see text] was calculated using Fick's equation. Linear regression slopes for oxygen cost (∆[Formula: see text]O₂/∆work rate) and [Formula: see text] to [Formula: see text]O₂ (∆[Formula: see text]/∆[Formula: see text]O₂) were calculated. Normally distributed data were reported as mean ± SD and non-normal data as median [interquartile range].

RESULTS

[Formula: see text]O_2peak was lower in FM patients than in controls (22.2 ± 5.1 vs. 31.1 ± 7.9 mL∙min^-1∙kg^-1, P < 0.001; 35.7 ± 7.1 vs. 44.0 ± 8.6 mL∙min^-1∙kg FFM^-1, P < 0.001). [Formula: see text] and C(a-v)O₂ were similar between groups at submaximal work rates, but peak [Formula: see text] (14.17 [13.34-16.03] vs. 16.06 [15.24-16.99] L∙min^-1, P = 0.005) and C(a-v)O₂ (11.6 ± 2.7 vs. 13.3 ± 3.1 mL O₂∙100 mL blood^-1, P = 0.031) were lower in the FM group. No significant group differences emerged in ∆[Formula: see text]O₂/∆work rate (11.1 vs. 10.8 mL∙min^-1∙W^-1, P = 0.248) or ∆[Formula: see text]/∆[Formula: see text]O₂ (6.58 vs. 5.75, P = 0.122) slopes.

CONCLUSIONS

Both [Formula: see text] and C(a-v)O₂ contribute to lower [Formula: see text]O_2peak in FM. The exercise responses were normal and not suggestive of a muscle metabolism pathology.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03300635. Registered 3 October 2017-Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT03300635 .

Coexistence of fibromyalgia syndrome and inflammatory rheumatic diseases, and autonomic cardiovascular system involvement in fibromyalgia syndrome

The spectrum of symptoms represented by fibromyalgia syndrome (FMS) has a profound effect on daily activities and impairs the quality of life. A considerable proportion of patients with inflammatory rheumatic diseases (IRDs) fulfill the FMS criteria, which can complicate the diagnosis, treatment, and follow-ups of IRD. In addition, the coexistence of FMS may cause unnecessary laboratory and radiological assessments. Several mechanisms have been proposed that may have a role in the etiopathogenesis of FMS, one of which is autonomic dysregulation. In studies evaluating cardiac autonomic dysfunction based on heart rate variability (HRV), there has been found to be a decrease in HRV and dominance of the sympathetic nervous system. Autonomic reactivity reflects modulations of several functions to overcome the existing state and conditions. Blunted autonomic reactivity has been found in some FMS patients, which makes it difficult for these patients to respond appropriately to unexpected stress sources that occur during daily living activities. Baroreceptor signals have an inhibitory influence on the central nervous system, and these impulses cause pain suppression. From this perspective, there are studies that have suggested the involvement of diminished baroreflex sensitivity in the etiology of FMS. The risk of endothelial dysfunction and increased arterial stiffness have been shown to occur in FMS patients due to autonomic dysfunction, sympathetic nervous system dominance, chronic stress, and pain. There is also evidence linking FMS with the risk of atrial and ventricular arrhythmias. Considering all these cardiovascular autonomic dysfunctions, tests that can confirm abnormalities should be performed when suspicion arises. There is a need for specific pharmacological and non-pharmacological treatment alternatives to be identified for subgroups of patients with cardiovascular system abnormalities. Key points • The frequency of FMS accompanying inflammatory rheumatic diseases is considerable and this coexistence leads to troubles in evaluating treatment response and determining appropriate medical treatment options in inflammatory rheumatic diseases. • Various cardiovascular autonomic abnormalities have been described in FMS patients. Among these, the most emphasized are autonomic dysfunction, the disruption of the balance between the sympathetic-parasympathetic nervous systems, blunted autonomic reactivity to acute stress, changes in baroreflex sensitivity, increased arterial stiffness, and electrophysiological alterations. • Autonomic cardiovascular dysfunction may be involved in the complex etiopathogenesis of the fibromyalgia syndrome and may trigger at least some symptoms.

Heart Rate Variability and Salivary Biomarkers Differences between Fibromyalgia and Healthy Participants after an Exercise Fatigue Protocol: An Experimental Study

Previous studies showed that people with Fibromyalgia (FM) suffer from dysautonomia. Dysautonomia consists of persistent autonomic nervous system hyperactivity at rest and hyporeactivity during stressful situations. There is evidence that parameters reflecting the complex interplay between the autonomic nervous system and the cardiovascular system during exercise can provide significant prognostic information. Therefore, this study aimed to investigate the differences between people with FM and healthy controls on heart rate variability (HRV) and salivary parameters (such as flow, protein concentration, enzymatic activities of amylase, catalase and glutathione peroxidase) in two moments: (1) at baseline, and (2) after an exercise fatigue protocol. A total of 37 participants, twenty-one were people with fibromyalgia and sixteen were healthy controls, participated in this cross-sectional study. HRV and salivary samples were collected before and after an exercise fatigue protocol. The fatigue protocol consisted of 20 repetitions of knee extensions and flexions of the dominant leg at 180 °·s⁻¹ (degrees per second). Significant differences were found in the HRV (stress index, LF and HF variables) and salivary biomarkers (with a higher concentration of salivary amylase in people with FM compared to healthy controls). Exercise acute effects on HRV showed that people with FM did not significantly react to exercise. However, significant differences between baseline and post-exercise on HRV significantly induce alteration on the HRV of healthy controls. Catalase significantly increased after exercise in healthy controls whereas salivary flow significantly increased in women with FM after an exercise fatigue protocol. Our study suggests that a higher α-amylase activity and an impaired HRV can be used as possible biomarkers of fibromyalgia, associated with a reduction in salivary flow without changes in HRV and catalase activity after a fatigue exercise protocol. More studies should be carried out in the future to evaluate this hypothesis, in order to find diagnostic biomarkers in fibromyalgia.

The Role of Depressive Disorders in Autonomic Cardiovascular Dysregulation in Fibromyalgia

OBJECTIVE

Previous research revealed aberrances in autonomic cardiovascular regulation in fibromyalgia, which may be relevant to symptoms genesis and the increased risk of cardiovascular disorders in individuals with fibromyalgia. This study investigated the role of comorbid depression in autonomic cardiovascular dysregulations in fibromyalgia.

METHODS

Cardiovascular recordings were obtained in 53 participants with fibromyalgia who also had depression ( n = 27), in participants with fibromyalgia without depression ( n = 26), and in 29 healthy controls, at rest and during a cold pressor test and an arithmetic task. Assessed parameters included interbeat interval, blood pressure, heart rate variability, baroreflex sensitivity, stroke volume, preejection period, left ventricular ejection time, Heather index, and total peripheral resistance.

RESULTS

Participants with both fibromyalgia and depression displayed lower tonic interbeat interval, baroreflex sensitivity, and heart rate variability compared with participants with fibromyalgia without depression and controls ( p values < .012, d values = 0.71-1.06). Participants with fibromyalgia but without depression did not differ from controls in these variables. Moreover, participants with fibromyalgia who also had depression, but not those without depression, exhibited lower Heather index, stroke volume, and left ventricular ejection time compared with controls ( p values < .013, d values = 0.62-0.78). No group differences arose for preejection period or total peripheral resistance. Stress reactivity was reduced in participants with fibromyalgia, independently of depression, for diastolic blood pressure, interbeat interval, left ventricular ejection time, and heart rate variability, than in controls.

CONCLUSIONS

The role of depression in the autonomic dysregulation in fibromyalgia involves chronotropic cardiac control rather than adrenergic influences on contractility and vascular tone. Blunted cardiovascular reactivity may be ascribable to pathological factors inherent to fibromyalgia. These results underline the importance of diagnostics and treatment of comorbid depressive disorders in the management of fibromyalgia.

Aging of Vascular System Is a Complex Process: The Cornerstone Mechanisms

Aging is one of the most intriguing processes of human ontogenesis. It is associated with the development of a wide variety of diseases affecting all organs and their systems. The victory over aging is the most desired goal of scientists; however, it is hardly achievable in the foreseeable future due to the complexity and ambiguity of the process itself. All body systems age, lose their performance, and structural disorders accumulate. The cardiovascular system is no exception. And it is cardiovascular diseases that occupy a leading position as a cause of death, especially among the elderly. The aging of the cardiovascular system is well described from a mechanical point of view. Moreover, it is known that at the cellular level, a huge number of mechanisms are involved in this process, from mitochondrial dysfunction to inflammation. It is on these mechanisms, as well as the potential for taking control of the aging of the cardiovascular system, that we focused on in this review.

What Mathematical Models Are Accurate for Prescribing Aerobic Exercise in Women with Fibromyalgia?

Simple Summary

Intensity prescription for cardiorespiratory exercises is crucial for achieving health/fitness benefits. However, not all of the population can access a cardiopulmonary exercise test, either for economic reasons or location resources, to determine their ventilatory thresholds. Therefore, different mathematical models can predict the intensity based on the maximum or reserve heart rate. Exercise prescription guidelines indicate that people with fibromyalgia should exercise at 60% of their VO₂max. However, people with fibromyalgia suffer from dysautonomia, which could lead to chronotropic incompetence, the inability to increase heart rate with increasing exercise intensities. Therefore, this study aimed to investigate the relationship and level of agreement between different mathematical models and the heart rate obtained from a cardiopulmonary exercise test at their ventilatory threshold 1. The results showed that the well-known “220 − age” at 76% and the mathematical model designed for people with fibromyalgia “209 − 0.85 × age” at 76% showed a significant level of agreement. However, Tanaka and Karvonen’s formula did not show a significant level of agreement. Thus, the “220 − age” at 76% and “209 − 0.85 × age” at 76% can be used in people with FM to prescribe aerobic exercise.

Abstract

Objectives: This article aims to verify the agreement between the standard method to determine the heart rate achieved in the ventilatory threshold 1 in the cardiopulmonary exercise testing (VT1) and the mathematical models with exercise intensities suggested by the literature in order to check the most precise for fibromyalgia (FM) patients. Methods: Seventeen women with FM were included in this study. The VT1 was used as the standard method to compare four mathematical models applied in the literature to calculate the exercise intensity in FM patients: the well-known “220 − age” at 76%, Tanaka predictive equation “208 − 0.7 × age” at 76%, the FM model HRMax “209 – 0.85 × age” at 76%, and Karvonen Formula at 60%. Bland–Altman analysis and correlation analyses were used to explore agreement and correlation between the standard method and the mathematical models. Results: Significant correlations between the heart rate at the VT1 and the four mathematical estimation models were observed. However, the Bland-Altman analysis only showed agreement between VT1 and “220 − age” (bias = −114.83 + 0.868 × x; 95% LOA = −114.83 + 0.868 × x + 1.96 × 7.46 to −114.83 + 0.868 × x − 1.96 × 7.46, where x is the average between the heart rate obtained in the CPET at VT1 and “220 − age”, in this case 129.15; p = 0.519) and “209 − 0.85 × age”(bias = −129.58 + 1.024 × x; 95% LOA = −129.58 + 1.024 × x + 1.96 × 6.619 to −129.58 + 1.024 × x − 1.96 × 6.619, where x is the average between the heart rate obtained in the CPET at VT1 and “209 − 0.85 × age”, in this case 127.30; p = 0.403). Conclusions: The well-known predictive equation “220 − age” and the FM model HRMax (“209 − 0.85 × age”) showed agreement with the standard method (VT1), revealing that it is a precise model to calculate the exercise intensity in sedentary FM patients. However, proportional bias has been detected in all the mathematical models, with a higher heart rate obtained in CPET than obtained in the mathematical model. The chronotropic incompetence observed in people with FM (inability to increase heart rate with increasing exercise intensities) could explain why methods that tend to underestimate the HRmax in the general population fit better in this population.

Cardiovascular risk assessment using ASCVD risk score in fibromyalgia: a single-centre, retrospective study using "traditional" case control methodology and "novel" machine learning

BACKGROUND

In autoimmune inflammatory rheumatological diseases, routine cardiovascular risk assessment is becoming more important. As an increased cardiovascular disease (CVD) risk is recognized in patients with fibromyalgia (FM), a combination of traditional CVD risk assessment tool with Machine Learning (ML) predictive model could help to identify non-traditional CVD risk factors.

METHODS

This study was a retrospective case-control study conducted at a quaternary care center in India. Female patients diagnosed with FM as per 2016 modified American College of Rheumatology 2010/2011 diagnostic criteria were enrolled; healthy age and gender-matched controls were obtained from Non-communicable disease Initiatives and Research at AMrita (NIRAM) study database. Firstly, FM cases and healthy controls were age-stratified into three categories of 18-39 years, 40-59 years, and ≥ 60 years. A 10 year and lifetime CVD risk was calculated in both cases and controls using the ASCVD calculator. Pearson chi-square test and Fisher's exact were used to compare the ASCVD risk scores of FM patients and controls across the age categories. Secondly, ML predictive models of CVD risk in FM patients were developed. A random forest algorithm was used to develop the predictive models with ASCVD 10 years and lifetime risk as target measures. Model predictive accuracy of the ML models was assessed by accuracy, f1-score, and Area Under 'receiver operating Curve' (AUC). From the final predictive models, we assessed risk factors that had the highest weightage for CVD risk in FM.

RESULTS

A total of 139 FM cases and 1820 controls were enrolled in the study. FM patients in the age group 40-59 years had increased lifetime CVD risk compared to the control group (OR = 1.56, p = 0.043). However, CVD risk was not associated with FM disease severity and disease duration as per the conventional statistical analysis. ML model for 10-year ASCVD risk had an accuracy of 95% with an f1-score of 0.67 and AUC of 0.825. ML model for the lifetime ASCVD risk had an accuracy of 72% with an f1-score of 0.79 and AUC of 0.713. In addition to the traditional risk factors for CVD, FM disease severity parameters were important contributors in the ML predictive models.

CONCLUSION

FM patients of the 40-59 years age group had increased lifetime CVD risk in our study. Although FM disease severity was not associated with high CVD risk as per the conventional statistical analysis of the data, it was among the highest contributor to ML predictive model for CVD risk in FM patients. This also highlights that ML can potentially help to bridge the gap of non-linear risk factor identification.

Impaired Cardiac Autonomic Control in Women With Fibromyalgia Is Independent of Their Physical Fitness

BACKGROUND/OBJECTIVE

Evidence has suggested abnormal cardiac autonomic responses to exercise in patients with fibromyalgia (FM). However, it is not clear whether the dysautonomia represents a reduced physical fitness rather directly related to FM pathogenesis. Thus, we aimed to verify the cardiac autonomic responses before, during, and after a maximal incremental exercise in women with FM and whether these hypothesized alterations would be dependent with their physical fitness.

METHODS

This is a cross-sectional study with 23 FM women and 17 healthy women. The participants performed a maximal incremental cycling test to determine their maximal workload (Wmax) and were further matched by their Wmax (14 FM patients, Wmax: 128.6 ± 16.2 W; and 14 healthy women, Wmax: 131.9 ± 15.9 W). Beat-to-beat heart rate (HR) was continuously monitored to calculate HR variability indexes at rest, chronotropic reserve during exercise, and HR recovery.

RESULTS

Heart rate variability indexes related to vagal modulation were significantly lower in FM patients than in healthy women (p < 0.05). The chronotropic reserve and the HR recovery at 30, 120, 180, 300, and 600 seconds after exercise were all lower in FM patients compared with those of healthy women (p < 0.05). Similar findings were found when analysis was performed using the matched physical fitness subgroup.

CONCLUSIONS

The documented cardiac autonomic abnormalities at rest, during, and after exercise in FM patients persist even when physical fitness status is taken in account. Thus, strategies to attenuate the dysautonomia in FM patients must be considered.

Heart rate response and chronotropic incompetence during cardiopulmonary exercise testing in childhood acute lymphoblastic leukemia survivors

Cardiopulmonary exercise tests (CPET) focusing on analyses of heart rate (HR) responses and chronotropic incompetence (CI) could provide early information about treatment's negative cardiac effects. We examined childhood acute lymphoblastic leukemia (ALL) survivors' HR response during maximal CPET and identified survivors with CI. A total of 250 childhood ALL survivors underwent a CPET on ergocycle to assess their HR response. We used a multiparametric structure of three methods to assess survivors' CI, as follows: 1) age-predicted HR_max (APMHR): failure to achieve 85% of the APMHR at the peak of CPET; 2) HR reserve (HRR): failure to achieve 80% of the HRR at the peak of CPET; and 3) metabolic chronotropic relationship (MCR): failure to reach an MCR slope ratio >0.8 at each stage of the CPET. Among 250 childhood ALL survivors, 216 survivors performed a maximum CPET. We observed that 73 males and 74 females did not achieve their predicted HR_max. We found that 6 survivors did not achieve 85% of their APMHR (80.9 ± 3.9%) and had an MCR below 80% (53.9 ± 13.8%). In addition, 16 survivors did not achieve 80% of their HRR (71.0 ± 7.4%) and among them, 15 survivors had an MCR below 80% (61.0 ± 12.1%). Survivors with CI had a significantly lower cardiorespiratory fitness than those without CI. This study shows that survivors are at risk of developing altered HR responses and CI many years after the end of their cancer treatments. These findings highlight the importance of early detection of cardiac damage due to cancer treatments.

Gulf War veterans exhibit broadband sleep EEG power reductions in regions overlying the frontal lobe

AIMS

Nearly a third of U.S. veterans who deployed in support of the 1990-1991 Persian Gulf War are affected by Gulf War illness (GWI). Here we aimed to characterize whether subjective sleep complaints in GWI veterans are associated with objective sleep EEG disturbances relative to healthy veterans and controls; and whether Gulf War veterans show alterations in neural activity during sleep that differentiate them from healthy subjects.

MAIN METHODS

We used high-density EEG (HDEEG) to assess regional patterns of rapid eye movement (REM) sleep and non-REM (NREM) sleep between three groups: Gulf War male veterans with fatigue and GWI, Gulf War male veterans without fatigue or GWI, and control males. The groups were matched relative to age, sex and obstructive sleep apnea. Topographic comparisons of nocturnal NREM and REM sleep were made between groups for all frequency bands.

KEY FINDINGS

Topographic analysis revealed a broadband reduction in EEG power in a circumscribed region overlying the frontal lobe in both groups of Gulf War veterans, regardless of GWI and fatigue. This frontal reduction in neural activity was present, to some extent, across all frequency bands in NREM and REM sleep.

SIGNIFICANCE

Given that our findings were observed in all Gulf War veterans, it appears unlikely that frontal sleep HDEEG power reductions prove wholly responsible for fatigue symptoms. These results provide avenues for research which may someday contribute to improved clinical care of formerly deployed veterans of the Persian Gulf War.

Free gait in a shallow pool accelerates recovery after exercise in model mice with fibromyalgia

This study aimed to determine the effect of pool gait exercise using fibromyalgia-induced model mice. The sensory threshold, locomotive behavior, electrocardiogram, and onset time after the gait test in shallow water using male C57BL/6J mice (weight, 30–35 g; n=21) were investigated. To induce fibromyalgia in model mice, reserpine was injected intraperitoneally into wild-type mice once a day for 3 days. Subsequently, the fibromyalgia-induced model mice were randomly classified into two groups as follows: the control group (n=11) and the pool gait group (n=10). The mice in the pool gait group walked in the same cage containing shallow warm water 5 times per week. Both groups underwent sensory thresholds and video recordings to determine locomotive behaviors weekly. Further, both heart rate and video recordings for observation of a recovery after the gait test in shallow water were undertaken (control group; n=5, pool gait group; n=5). The pool gait did not affect sensory thresholds and locomotive behavior; however, in the pool gait group, both the recovery after the test, such as onset time and gait distance, were considerably better than those of the control group. Furthermore, changes in heart rate and heart rate irregularity after the test were more apparent in the control group than in the pool gait group. The free gait in a shallow pool accelerated recovery after exercise, unlike the sensory threshold.

Excessive exercise induces cardiac arrhythmia in a young fibromyalgia mouse model

Background

Fibromyalgia patients experience cardiovascular complications in addition to musculoskeletal pain. This study aimed to investigate the cardiac effects of a prolonged shallow water gait in a fibromyalgia-induced young mouse model.

Methods

To produce a fibromyalgia mouse model, wild-type mice were administered an intraperitoneal injection of reserpine once a day for three days, and two primary experiments were performed. First, three types of gait tests were performed before and after the reserpine injections as follows: (i) 5 minutes of free gait outside the water, (ii) 1 minute of free gait in shallow warm water, and (iii) 5 minutes of free gait in shallow warm water. Second, electrocardiogram recordings were taken before and after the three gait tests. The average heart rate and heart rate irregularity scores were analyzed.

Results

Exercise-induced cardiac arrhythmia was observed at 1-minute gait in shallow water during the acute stage of induced FM in young mice. Further, both cardiac arrhythmia and a decrease in HR have occurred at 5-minute gait in shallow water at the same mice. However, this phenomenon was not observed in the wild-type mice under any test conditions.

Conclusion

Although a short-term free gait in shallow warm water may be advantageous for increasing the motor activity of FM-model mice, we should be aware of the risk of prolonged and excessive exercise-induced cardiac arrhythmia. For gait exercises in shallow water as a treatment in FM patients. We suggest a gradual increase in exercise duration may be warranted.

Subclinical cardiac structural and electrical abnormalities in fibromyalgia syndrome

Background/aim

In the literature, there is a paucity of data about the effects of fibromyalgia syndrome (FMS) on myocardial function and electrophysiological properties of atrium and ventricles. In this study, we investigated cardiac functions and noninvasive predictors of arrhythmias in patients with FMS.

Materials and methods

The study included 43 female patients diagnosed with FMS and 30 age- and sex-matched healthy subjects. The presence of fragmented QRS (fQRS) morphology, P dispersion, QT dispersion, inter- and intraatrial electromechanical delay was evaluated in the groups with 12-lead ECG and standard and tissue Doppler echocardiography.

Results

Among electrocardiographic parameters, P dispersion, QT dispersion, and the ratio of presence of fQRS morphology were found to be significantly higher in the study group as compared to the control group. In lateral and septal, the ratio of the early transmitral flow velocity to the early diastolic tissue velocity (E/Em) was significantly higher in the study group. Additionally, intra- and interatrial electromechanical delay was found significantly prolonged in the study group.

Conclusion

FMS is found to be associated with significant cardiac electrical alterations that may indicate the increased risk of atrial and ventricular arrhythmias in this group of patients.

Impact of a specific training programme on the neuromodulation of pain in female patient with fibromyalgia (DouFiSport): a 24-month, controlled, randomised, double-blind protocol

INTRODUCTION

The main symptom of fibromyalgia (FM) is diffuse pain. There is currently no aetiological treatment for FM. However, all pain associations and best practice guidelines strongly advocate the practice of aerobic physical activity to improve the symptoms of FM subjects. The mechanisms of dysfunctional pain are mostly central and related to stress axis dysfunction (autonomic nervous system and corticotropic axis). Our main objective is to assess the efficacy of a specific training programme on endogenous pain control mechanisms in female patients with FM. Further aims include rebalancing the autonomic neurovegetative system, improving quality of life and sleep quality, and reintegrating patients into society and work.

METHODS AND ANALYSIS

110 female patients with FM diagnosed on American College of Rheumatology 2010 criteria, aged 18-65 years and meeting inclusion conditions will be recruited and randomised into two groups (active and semiactive). The training programme will consist of three 45 min sessions per week of supervised, individualised physical activity over 2 years. Only the intensity of the exercises will differ between the two groups (moderate intensity vs low intensity).All outcome measures will be conducted at baseline (T0), after 6-9 months of training (T6-9) and after 24 months of training (T24). The primary endpoint will be an improvement of pain modulation (activation of diffuse noxious inhibitory control) evaluated by the stimulation test. The secondary endpoint will be relief of pain, anxiety, depression, stress, sleep disorders, pain impact on life quality, and improved heart rate, blood pressure and salivary cortisol.

ETHICS AND DISSEMINATION

This study is approved by the Committee for the Protection of Persons West VI. The results will be published in specialised scientific journals and will be presented at scientific meetings on pain and/or physical activity.

TRIAL REGISTRATION NUMBER

NCT02486965; Pre-results.

Cardiorespiratory fitness among adults with fibromyalgia

This review presents and addresses the conflicting results on cardiorespiratory fitness among adults with fibromyalgia. The heterogeneity in study designs, symptom severity and the assessment protocols might partly explain these conflicting results. It also presents the possible relationship between cardiorespiratory fitness and exercise prescription, attrition from exercise/rehabilitation programmes and independence with activities of daily living. Cardiorespiratory fitness might impact aerobic exercise and independence in daily activities of patients with fibromyalgia, which is often concomitantly diagnosed in patients with sleep disordered breathing, including patients with obstructive sleep apnoea. Therefore, cardiorespiratory fitness evaluation should be considered by general and respiratory physicians as well as physiotherapists who treat patients diagnosed with fibromyalgia for more accurate diagnosis, exercise prescription and monitoring of patients' status.

Key points

Adults with fibromyalgia often present with reduced cardiorespiratory fitness.Reduced cardiorespiratory fitness might have an important impact on functional capacity and quality of life.Adults with fibromyalgia who have a secondary condition affecting their ventilatory anaerobic threshold and/or V'_O2peak, for example chronic obstructive pulmonary disease, might present with a greater reduction of their cardiorespiratory fitness which may not be entirely related to their lung disease.

Educational aims

To better understand the cardiorespiratory fitness results among adults with fibromyalgia in general, and when taking into account differences in assessment protocol (maximal versus submaximal testing protocol; cycle ergometer versus treadmill testing protocol) and symptom severity (fibromyalgia severity level).To better understand how cardiorespiratory fitness among adults with fibromyalgia could: 1) assist in exercise prescription; 2) minimise dropout rates from exercise/rehabilitation programmes; and 3) promote independence with activities of daily living.To learn why fibromyalgia might be important to consider in adults who have concurrent fibromyalgia and lung disease.

The Association Between Chronic Pain and Cardiac Disease: A Cross-sectional Population Study

OBJECTIVES

Chronic pain may increase the risk of cardiac disease, but the extent to which confounding variables account for this association has yet to be satisfactorily established. This study aims to examine the possibility of an independent association between these 2 variables.

METHODS

We applied logistic regression analysis to data from 8596 adults surveyed in a population study of the health of the population of England. The association between cardiac disease (angina and/or myocardial infarction) and chronic pain (pain lasting >3 months) was explored, taking account of 10 potentially confounding variables including the regular use of nonsteroidal anti-inflammatory drugs.

RESULTS

Participants reporting chronic pain (n=3023) were more likely to experience cardiac disease than those without pain: odds ratio (OR), 1.55; 95% confidence interval (CI), 1.15-2.07. Subsets of participants fulfilling various criteria for high-intensity chronic pain demonstrated stronger associations with cardiac disease suggesting a "dose-response" element to the relationship: chronic widespread pain (OR, 3.3; 95% CI, 1.42-7.68); higher-disability chronic pain (OR, 2.35; 95% CI, 1.71-3.23); and higher average chronic pain score (OR, 1.95; 95% CI, 1.40-2.71). Adjustment for regular prescription of nonsteroidal anti-inflammatory drugs did not reduce the association of chronic pain with cardiac disease.

DISCUSSION

Patients reporting chronic pain, in particular those most severely affected, may be at significantly increased risk of cardiac disease. Future studies should focus on determining whether reducing the impact of chronic pain can improve cardiac health.

Exercise prevents development of autonomic dysregulation and hyperalgesia in a mouse model of chronic muscle pain

Chronic musculoskeletal pain (CMP) conditions, like fibromyalgia, are associated with widespread pain and alterations in autonomic functions. Regular physical activity prevents the development of CMP and can reduce autonomic dysfunction. We tested if there were alterations in autonomic function of sedentary mice with CMP, and whether exercise reduced the autonomic dysfunction and pain induced by CMP. Chronic musculoskeletal pain was induced by 2 intramuscular injections of pH 5.0 in combination with a single fatiguing exercise task. A running wheel was placed into cages so that the mouse had free access to it for either 5 days or 8 weeks (exercise groups) and these animals were compared to sedentary mice without running wheels. Autonomic function and nociceptive withdrawal thresholds of the paw and muscle were assessed before and after induction of CMP in exercised and sedentary mice. In sedentary mice, we show decreased baroreflex sensitivity, increased blood pressure variability, decreased heart rate variability, and decreased withdrawal thresholds of the paw and muscle 24 hours after induction of CMP. There were no sex differences after induction of the CMP in any outcome measure. We further show that both 5 days and 8 weeks of physical activity prevent the development of autonomic dysfunction and decreases in withdrawal threshold induced by CMP. Thus, this study uniquely shows the development of autonomic dysfunction in animals with chronic muscle hyperalgesia, which can be prevented with as little as 5 days of physical activity, and suggest that physical activity may prevent the development of pain and autonomic dysfunction in people with CMP.

Assessing the relationship between chronic pain and cardiovascular disease: A systematic review and meta-analysis

Background and Aims

Chronic pain is a potentially disabling condition affecting one in three people through impaired physical function and quality of life. While the psychosocial impact of chronic pain is already well established, little is known about the potential biological consequences. Chronic pain may be associated with an increased prevalence of cardiovascular disease, an effect that has been demonstrated across a spectrum of chronic pain conditions including low back pain, pelvic pain, neuropathic pain and fibromyalgia. The aim of this study was to review and summarize the evidence for a link between chronic pain and cardiovascular disease. We sought to clarify the nature of the relationship by examining the basis for a dose-response gradient (whereby increasing pain severity would result in greater cardiovascular disease), and by evaluating the extent to which potentially confounding variables may contribute to this association.

Methods

Major electronic databases MEDLINE, EMBASE, Psychinfo, Cochrane, ProQuest and Web of Science were searched for articles reporting strengths of association between chronic pain (pain in one or more body regions, present for three months or longer) and cardiovascular outcomes (cardiovascular mortality, cardiac disease, and cerebrovascular disease). Meta-analysis was used to pool data analysing the association between chronic pain and the three principal cardiovascular outcomes. The impact of pain severity, and the role of potentially confounding variables were explored narratively.

Results

The searches generated 11,141 studies, of which 25 matched our inclusion criteria and were included in the review. Meta-analysis (of unadjusted study outcomes) demonstrated statistically significant associations between chronic pain and mortality from cardiovascular diseases: pooled odds ratio 1.20, (95% confidence intervals 1.05–1.36); chronic pain and cardiac disease: pooled odds ratio 1.73 (95% confidence intervals 1.42–2.04); and chronic pain and cerebrovascular disease: pooled odds ratio 1.81 (95% confidence intervals 1.51–2.10). The systematic review also found evidence supporting a dose-response relationship, with greater pain intensity and distribution producing a stronger association with cardiovascular outcomes.

All of the included studies were based on observational data with considerable variation in chronic pain taxonomy, methodology and study populations. The studies took an inconsistent and incomplete approach in their adjustment for potentially confounding variables, making it impossible to pool data after adjustments for confounding variables, so it cannot be concluded that these associations are causal.

Conclusions

Our review supports a possible dose-response type of association between chronic pain and cardiovascular disease, supported by a range of observational studies originating from different countries. Such research has so far failed to satisfactorily rule out that the association is due to confounding variables. What is now needed are further population based longitudinal studies that are designed to allow more robust exploration of a cause and effect relationship.

Implications

Given the high prevalence of chronic pain in developed and developing countries our results highlight a significant, but underpublicized, public health concern. Greater acknowledgement of the potentially harmful biological consequences of chronic pain may help to support regional, national and global initiatives aimed at reducing the burden of chronic pain.

Dysfunctional stress responses in chronic pain

Many dysfunctional and chronic pain conditions overlap. This review describes the different modes of chronic deregulation of the adaptive response to stress which may be a common factor for these conditions. Several types of dysfunction can be identified within the hypothalamo-pituitary-adrenal axis: basal hypercortisolism, hyper-reactivity, basal hypocortisolism and hypo-reactivity. Neuroactive steroid synthesis is another component of the adaptive response to stress. Dehydroepiandrosterone (DHEA) and its sulfated form DHEA-S, and progesterone and its derivatives are synthetized in cutaneous, nervous, and adipose cells. They are neuroactive factors that act locally. They may have a role in the localization of the symptoms and their levels can vary both in the central nervous system and in the periphery. Persistent changes in neuroactive steroid levels or precursors can induce localized neurodegeneration. The autonomic nervous system is another component of the stress response. Its dysfunction in chronic stress responses can be expressed by decreased basal parasympathethic activity, increased basal sympathetic activity or sympathetic hyporeactivity to a stressful stimulus. The immune and genetic systems also participate. The helper-T cells Th1 secrete pro-inflammatory cytokines such as IL-1-β, IL-2, IL-6, IL-8, IL-12, IFN-γ, and TNF-α, whereas Th2 secrete anti-inflammatory cytokines: IL-4, IL-10, IGF-10, IL-13. Chronic deregulation of the Th1/Th2 balance can occur in favor of anti- or pro-inflammatory direction, locally or systemically. Individual vulnerability to stress can be due to environmental factors but can also be genetically influenced. Genetic polymorphisms and epigenetics are the main keys to understanding the influence of genetics on the response of individuals to constraints.

Fibromyalgia: A Critical and Comprehensive Review

Fibromyalgia is a disorder that is part of a spectrum of syndromes that lack precise classification. It is often considered as part of the global overview of functional somatic syndromes that are otherwise medically unexplained or part of a somatization disorder. Patients with fibromyalgia share symptoms with other functional somatic problems, including issues of myalgias, arthralgias, fatigue and sleep disturbances. Indeed, there is often diagnostic and classification overlap for the case definitions of a variety of somatization disorders. Fibromyalgia, however, is a critically important syndrome for physicians and scientists to be aware of. Patients should be taken very seriously and provided optimal care. Although inflammatory, infectious, and autoimmune disorders have all been ascribed to be etiological events in the development of fibromyalgia, there is very little data to support such a thesis. Many of these disorders are associated with depression and anxiety and may even be part of what has been sometimes called affected spectrum disorders. There is no evidence that physical trauma, i.e., automobile accidents, is associated with the development or exacerbation of fibromyalgia. Treatment should be placed on education, patient support, physical therapy, nutrition, and exercise, including the use of drugs that are approved for the treatment of fibromyalgia. Treatment should not include opiates and patients should not become poly pharmacies in which the treatment itself can lead to significant morbidities. Patients with fibromyalgia are living and not dying of this disorder and positive outlooks and family support are key elements in the management of patients.

Cardiac autonomic functions in children with familial Mediterranean fever

Familial Mediterranean fever (FMF) is the most common inherited autoinflammatory disease in the world. The long-term effects of subclinical inflammation in FMF are not well recognized. Some studies have suggested that FMF is associated with cardiac autonomic dysfunction in adult FMF patients. The objective of this study was to investigate the cardiac autonomic functions in pediatric FMF patients by using several autonomic tests. Thirty-five patients with FMF and 35 healthy controls were enrolled in this cross-sectional study. Demographic data, disease-specific data, and orthostatic symptoms were recorded. In all participants, 12-lead electrocardiography (ECG), 24 h ambulatory electrocardiographic monitoring, transthoracic echocardiography, treadmill exercise test, and head upright tilt-table (HUTT) test were performed. The heart rate recovery (HRR) indices of the two groups were similar. Also, chronotropic response was similar in both groups. The time-domain parameters of heart rate variability (HRV) were similar in both groups, except mean RR (p = 0.024). Frequencies of ventricular and supraventricular ectopic stimuli were similar in both groups. There were no statistically significant differences between the groups in average QT and average corrected QT interval length, average QT interval dispersion, and average QT corrected dispersion. There was no significant difference between the two groups regarding the ratio of clinical dysautonomic reactions on HUTT. However, we observed a significantly higher rate of dysautonomic reactions on HUTT in patients with exertional leg pain than that in patients without (p = 0.013). When the fractal dimension of time curves were compared, FMF patients exhibited significantly lower diastolic blood pressure parameters than controls in response to HUTT. Cardiovascular autonomic dysfunction in children with FMF is not prominent. Particularly, patients with exertional leg pain are more prone to have dysautonomic features. Further studies are needed to elucidate the exact mechanisms leading to impaired cardiac autonomic functions in FMF.

Patients With Fibromyalgia Have Significant Autonomic Symptoms But Modest Autonomic Dysfunction

BACKGROUND

Research suggests that disordered autonomic function may be one contributor to deconditioning reported in fibromyalgia; however, no study to date has assessed these variables simultaneously with comprehensive measures.

OBJECTIVE

To characterize physical fitness and autonomic function with the use of clinically validated measures and subjective questionnaires between patients with fibromyalgia and healthy controls.

DESIGN

Cross-sectional, observational, controlled study.

SETTING

Community sample of patients with fibromyalgia and healthy controls.

PARTICIPANTS

Thirty patients with fibromyalgia and 30 pain and fatigue-free controls.

METHODS

Participants completed a battery of self-report questionnaires and physiological measures, including clinically validated measures of physical fitness and autonomic function.

MAIN OUTCOME MEASUREMENTS

Six-Minute Walk Test total distance, maximal oxygen consumption as assessed by cardiopulmonary exercise testing, total steps using activity monitor, Composite Autonomic Scoring Scale as assessed by Autonomic Reflex Screen, total metabolic equivalents per week using the International Physical Activity Questionnaire, and self-reported autonomic symptoms via the 31-item Composite Autonomic Symptom Score questionnaire.

RESULTS

Autonomic function, as assessed by self-report, was significantly different between patients and controls (P < .0001); in contrast, the only difference between patients and controls on the Autonomic Reflex Screen was in the adrenergic domain (P = .022), and these abnormalities were mild. Self-reported physical activity was not significantly different between patients and controls (P = .99), but levels of moderate and vigorous physical activity as measured by actigraphy were significantly lower in patients (P = .012 and P = .047, respectively). Exercise capacity (6-Minute Walk) was poorer in patients (P = .0006), but there was no significant difference in maximal volume of oxygen consumption (P = .07).

CONCLUSIONS

Patients with fibromyalgia report more severe symptoms across all domains, including physical activity and autonomic symptoms, compared with controls, but the objective assessments only showed modest differences. Our results suggest that patients with widespread subjective impairment of function have only modest objective measures of autonomic dysfunction. We recommend that the primary treatment goal should be focused on restoration of function, which may also ameliorate symptoms.

Quantitative analysis of nailfold capillary morphology in patients with fibromyalgia

BACKGROUND/AIMS

Nailfold capillaroscopy (NFC) has been used to examine morphological and functional microcirculation changes in connective tissue diseases. It has been demonstrated that NFC patterns reflect abnormal microvascular dynamics, which may play a role in fibromyalgia (FM) syndrome. The aim of this study was to determine NFC patterns in FM, and their association with clinical features of FM.

METHODS

A total of 67 patients with FM, and 30 age- and sex-matched healthy controls, were included. Nailfold capillary patterns were quantitatively analyzed using computerized NFC. The parameters of interest were as follows: number of capillaries within the central 3 mm, deletion score, apical limb width, capillary width, and capillary dimension. Capillary dimension was determined by calculating the number of capillaries using the Adobe Photoshop version 7.0.

RESULTS

FM patients had a lower number of capillaries and higher deletion scores on NFC compared to healthy controls (17.3 ± 1.7 vs. 21.8 ± 2.9, p < 0.05; 2.2 ± 0.9 vs. 0.7 ± 0.6, p < 0.05, respectively). Both apical limb width (µm) and capillary width (µm) were significantly decreased in FM patients (1.1 ± 0.2 vs. 3.7 ± 0.6; 5.4 ± 0.5 vs. 7.5 ± 1.4, respectively), indicating that FM patients have abnormally decreased digital capillary diameter and density. Interestingly, there was no difference in capillary dimension between the two groups, suggesting that the length or tortuosity of capillaries in FM patients is increased to compensate for diminished microcirculation.

CONCLUSIONS

FM patients had altered capillary density and diameter in the digits. Diminished microcirculation on NFC may alter capillary density and increase tortuosity.

Heart rate turbulence analysis in female patients with fibromyalgia

OBJECTIVE

Fibromyalgia is characterized by diffuse musculoskeletal pain and discomfort. There are several reports regarding autonomic nervous system dysfunction in patients with fibromyalgia. Heart rate turbulence is expressed as ventriculophasic sinus arrhythmia and has been considered to reflect cardiac autonomic activity. Heart rate turbulence has been shown to be an independent and powerful predictor of sudden cardiac death in various cardiac abnormalities. The aim of this study is to determine whether heart rate turbulence is changed in female patients with fibromyalgia compared with healthy controls.

METHODS

Thirty-seven female patients (mean age, 40±11 years) with fibromyalgia, and 35 age- and sex-matched healthy female control subjects (mean age, 42±9 years) were included. Twenty-four hours of ambulatory electrocardiography recordings were collected for all subjects, and turbulence onset and turbulence slope values were automatically calculated.

RESULTS

The baseline clinical characteristics of the two groups were similar. There were no significant differences in turbulence onset and turbulence slope measures between patients and control subjects (turbulence onset: -1.648±1.568% vs. -1.582±1.436%, p ϝ 0.853; turbulence slope: 12.933±5.693 ms/RR vs. 13.639±2.505 ms/RR, p ϝ 0.508). Although body mass index was negatively correlated with turbulence slope (r ϝ -0.258, p ϝ 0.046), no significant correlation was found between body mass index and turbulence onset (r ϝ 0.228, p ϝ 0.054).

CONCLUSION

To the best of our knowledge, this is the first study to evaluate heart rate turbulence in patients with fibromyalgia. It appears that heart rate turbulence parameters reflecting cardiac autonomic activity are not changed in female patients with fibromyalgia.

Effect of Pregabalin on Cardiovascular Responses to Exercise and Postexercise Pain and Fatigue in Fibromyalgia: A Randomized, Double-Blind, Crossover Pilot Study

Pregabalin, an approved treatment for fibromyalgia (FM), has been shown to decrease sympathetic nervous system (SNS) activity and inhibit sympathetically maintained pain, but its effects on exercise responses have not been reported. Methods. Using a randomized double-blind crossover design, we assessed the effect of 5 weeks of pregabalin (versus placebo) on acute cardiovascular and subjective responses to moderate exercise in 19 FM patients. Blood pressure (BP), heart rate (HR), and ratings of perceived exertion (RPE) during exercise and ratings of pain, physical fatigue, and mental fatigue before, during, and for 48 hours after exercise were compared in patients on pregabalin versus placebo and also versus 18 healthy controls. Results. On placebo, exercise RPE and BP were significantly higher in FM patients than controls (p < 0.04). Pregabalin responders (n = 12, defined by patient satisfaction and symptom changes) had significantly lower exercise BP, HR, and RPE on pregabalin versus placebo (p < 0.03) and no longer differed from controls (p > 0.26). Cardiovascular responses of nonresponders (n = 7) were not altered by pregabalin. In responders, pregabalin improved ratings of fatigue and pain (p < 0.04), but negative effects on pain and fatigue were seen in nonresponders. Conclusions. These preliminary findings suggest that pregabalin may normalize cardiovascular and subjective responses to exercise in many FM patients.

Safety and feasibility of maximal physical testing in rheumatic diseases: a cross-sectional study with 5,910 assessments

The purpose of the study was to report on the safety and feasibility of the application of maximal physical tests in a heterogeneous cohort of rheumatic patients. This is a 5-year retrospective descriptive report on the incidence of events associated with maximal physical testing from 536 patients, totalizing 5,910 tests. Tests were classified as cardiopulmonary, muscle strength, and physical functioning tests. Any adverse events during the tests and limiting factors incurring in tests cancellation were reported. Eighteen out of 641 cardiopulmonary exercise tests had an adverse occurrence, with cardiac disturbance (1.4% of total tests) being the most prevalent. Moreover, 14 out of 641 tests were not feasible. Out of 3,478 tests comprising leg press, bench press, knee extension, and handgrip tests, 15 tests had an adverse event. The most common occurrence was joint pain (0.4% of total tests), which was also the most frequent factor precluding testing (0.5% of total tests). Forty-five out of 3,478 (1.3%) of the tests were not feasible. There was a very low incidence of events (0.2%) during the physical functioning tests. Joint pain was the only adverse event during the tests, whereas physical limitations were the most important barriers for the execution of the tests (1.1% of total tests). The incidence of limiting events in this test was 1.6% (n = 29). This report brings new data on the safety and feasibility of maximal physical testing in rheumatic patients. The physical tests described in this study may be applied for testing rheumatic patients both in research and clinical setting.

Association between fibromyalgia and adverse perioperative outcomes

BACKGROUND

Fibromyalgia, the classic non-inflammatory pain syndrome, has been associated with chronic inflammatory makers which are linked with increased morbidity and mortality. We tested the primary hypothesis that patients with fibromyalgia undergoing hospital procedures have a high risk of cardiovascular complications. Our secondary goals were to evaluate the association of fibromyalgia with: (i) in-hospital thromboembolic events, (ii) in-hospital mortality, and (iii) in-hospital microvascular complications.

METHODS

We obtained 21.78 million discharge records from 2009 to 2010 from the US Agency for Healthcare Research and Quality censuses across the seven states. We matched fibromyalgia records and compared records with controls based on age, gender, state of discharge, principal procedure, and a propensity score developed from the set of diagnosis-related predictors. A multivariable logistic regression was used to compare matched fibromyalgia patients and controls on the primary and secondary outcomes.

RESULTS

We matched 89 589 pairs for a total sample size of 179 178 discharge records. The adjusted odds ratio for in-hospital cardiovascular complications was 1.04 [99% confidence interval (CI): 0.90-1.19, P=0.51], for thromboembolic events was 1.03 (99% CI: 0.93-1.15, P=0.46), for in-hospital mortality was 0.81 (99% CI: 0.73-0.89, P<0.001), and for microvascular complications was 0.96 (99% CI: 0.88, 1.04, P=0.18). Two separate sensitivity analyses produced results similar to that of the primary analysis for all three complication outcomes.

CONCLUSIONS

We found no evidence that the diagnosis of fibromyalgia increased the risk of in-hospital complications. Fibromyalgia seems to be associated with a reduction in in-hospital mortality, but this requires confirmation with a large prospective controlled study.

Autonomic testing of women with interstitial cystitis/bladder pain syndrome

Purpose

Interstitial cystitis/bladder pain syndrome (IC/BPS) is characterized by urinary urgency, frequency, nocturia, pain worse as the bladder fills and improved after emptying. These features might suggest abnormal autonomic bladder control mechanisms. We compared the structural integrity of the autonomic nervous system (ANS) in IC/BPS and control subjects.

Methods

IRB-approved study at University Hospitals Case Medical Center, Cleveland, OH to evaluate the structural integrity of the ANS in adult females. Testing included cardiovascular response to deep breathing, Valsalva maneuver, 30 min head up tilt, and sudomotor test.

Results

Differences in ANS integrity for IC/BPS subjects and controls were determined by modified Composite Autonomic Severity Score (CASS) that includes sudomotor, adrenergic and cardiovascular indices. Baseline heart rate (HR) and HRs from each of three 10 min upright segments of a tilt test were compared and trend analyses performed using t tests. Healthy and IC/BPS subjects were demographically similar. The two groups did not differ in modified-CASS scores but elevated average peak heart rate was evident during baseline (supine; p = 0.057) for IC/BPS subjects prior to a tilt test. Difference at baseline was maintained at each interval during the tilt, with nearly identical slopes across intervals. The preliminary nature of this report denotes a small sample size and important differences may not be detected.

Conclusions

The findings show no structural ANS abnormalities in IC/BPS subjects. Higher baseline HR supports the concept of functional rather than structural change in the ANS, such as abnormality of sympathetic/parasympathetic balance that will require further evaluation.

Exercise Profile and Diastolic Functions Measured via Tissue Doppler Imaging of Fibromyalgia Patients

Background

Our aim was to evaluate electrocardiographic and echocardiographic properties and exercise response of patients with fibromyalgia (FM).

Methods

The study included 60 women with primary FM and 30 healthy individuals. Resting electrocardiography, echocardiography and exercise treadmill test were used to compare these two groups. At apical four-chamber window, samples of transmitral diastolic inflow and tissue Doppler imaging of left ventricle lateral wall were obtained. Left ventricle ejection fraction was measured via modified Simpson’s method. Exercise duration, maximal exercise capacity, maximal heart rate (HR) (bpm), maximal HR (%), rate-pressure product at maximal HR (bpm × mmHg), heart rate recovery 1 (bpm), heart rate recovery 2 (bpm) and chronotropic reserve (%) values were calculated.

Results

Resting HR and QTc values were similar in both groups. Echocardiographic measurements in both groups did not reveal statistically significant difference except left ventricle end-diastolic diameter and left atrial diameter. Parameters related to diastolic function of the left ventricle did not differ significantly in both groups. Also, there was not any significant difference between the groups for E/E’ ratio and chronotropic reserve. Exercise treadmill test results were statistically similar for both groups.

Conclusion

Patients with FM presented a normal HR response to exercise and those patients had normal diastolic function similar to their healthy controls.

Discriminative validity of metabolic and workload measurements for identifying people with chronic fatigue syndrome

BACKGROUND

Reduced functional capacity and postexertion fatigue after physical activity are hallmark symptoms of chronic fatigue syndrome (CFS) and may even qualify for biomarker status. That these symptoms are often delayed may explain the equivocal results for clinical cardiopulmonary exercise testing in people with CFS. Test reproducibility in people who are healthy is well documented. Test reproducibility may not be achievable in people with CFS because of delayed symptoms.

OBJECTIVE

The objective of this study was to determine the discriminative validity of objective measurements obtained during cardiopulmonary exercise testing to distinguish participants with CFS from participants who did not have a disability but were sedentary.

DESIGN

A prospective cohort study was conducted.

METHODS

Gas exchange data, workloads, and related physiological parameters were compared in 51 participants with CFS and 10 control participants, all women, for 2 maximal exercise tests separated by 24 hours.

RESULTS

Multivariate analysis showed no significant differences between control participants and participants with CFS for test 1. However, for test 2, participants with CFS achieved significantly lower values for oxygen consumption and workload at peak exercise and at the ventilatory or anaerobic threshold. Follow-up classification analysis differentiated between groups with an overall accuracy of 95.1%.

LIMITATIONS

Only individuals with CFS who were able to undergo exercise testing were included in this study. Individuals who were unable to meet the criteria for maximal effort during both tests, were unable to complete the 2-day protocol, or displayed overt cardiovascular abnormalities were excluded from the analysis.

CONCLUSIONS

The lack of any significant differences between groups for the first exercise test would appear to support a deconditioning hypothesis for CFS symptoms. However, the results from the second test indicated the presence of CFS-related postexertion fatigue. It might be concluded that a single exercise test is insufficient to reliably demonstrate functional impairment in people with CFS. A second test might be necessary to document the atypical recovery response and protracted fatigue possibly unique to CFS, which can severely limit productivity in the home and workplace.

Impaired aerobic exercise capacity and cardiac autonomic control in primary antiphospholipid syndrome

Primary antiphospholipid syndrome (PAPS) is associated with increased risk of cardiovascular disease and mortality. Aerobic capacity and cardiac autonomic control are also associated with these risks. The aim of our study was to assess aerobic capacity and cardiac autonomic control in PAPS patients. Thirteen women with PAPS and 13 healthy controls matched for age, gender, and body mass index were enrolled for the study. Both groups were sedentary and were not under chronotropic, antidepressants and hypolipemiant drugs. All subjects performed a treadmill-graded maximal exercise. Aerobic capacity was assessed by peak oxygen uptake (VO2peak), time at anaerobic ventilatory threshold (VAT) and respiratory compensation point (RCP) and time-to-exhaustion, whereas cardiac autonomic control was assessed by chronotropic reserve (CR) and heart rate recovery at the first and second minutes after graded exercise (HRR1min and HRR2min, respectively). All aerobic capacity indexes were reduced more in PAPS patients than in healthy subjects: VO2peak (30.2 ± 4.7 vs 34.6 ± 4.3 ml.kg−1.min−1, p = 0.021), time at VAT (3.0 ± 1.5 vs 5.0 ± 2.0 min, p = 0.016), time at RCP (6.5 ± 2.0 vs 8.0 ± 2.0 min, p = 0.050), time-to-exhaustion (8.5 ± 2.0 vs 11.0 ± 2.5 min, p = 0.010). HRR1min (22 ± 9 vs 30 ± 7 bpm, p = 0.032) and HRR2min (33 ± 9 vs 46 ± 8 bpm, p = 0.002) were delayed in PAPS patients compared to healthy controls but CR was not significantly different ( p = 0.272). In conclusion, an impaired aerobic capacity and cardiac autonomic control was identified in PAPS.

Urinary albumin, protein excretion and circadian blood pressure in patients with fibromyalgia

Recent evidence suggests that patients with fibromyalgia (FM) have increased oxidative stress, inflammation, endothelial dysfunction and autonomic dysfunction. These factors are also shown to be responsible for increased urinary albumin and protein excretion and deranged circadian blood pressure (BP). However, no study has examined the 24-h urinary albumin excretion (UAE), 24-h urinary protein excretion (UPE) and 24-h ambulatory BP measurements in FM patients. The sociodemographic, laboratory parameters, depressive symptoms, sleep problems and 24-h ambulatory BPs were measured for all patients. Diagnosis of FM was based on the criteria for the classification of FM by the American College of Rheumatology. After diagnosis of FM, these patients underwent to complete the Fibromyalgia Impact Questionnaire (FIQ). In total, 30 patients with FM and 61 patients without FM were included. Among FM patients, the average number of tender points was 13.1 ± 1.57 and the mean FIQ score was 57.9 ± 8.86. The number of tender points did not show any correlation with office and ambulatory BPs. There were also no correlations between the number of tender points, UPE and UAE. The stepwise linear regression did not show any relation between UPE and FM. However, 24-h UAE was independently correlated with office systolic BP (P 0.008) and the presence of FM (P 0.045). The logistic regression analysis revealed no association between FM and non-dipping status. We suggest that circadian blood pressure and UPE are not independently associated with FM. However, UAE was related with the presence of FM. Studies are needed to confirm our findings and to highlight pathophysiologic mechanisms.

Metabolic rate, cardiac response, and aerobic capacity in fibromyalgia: a case-control study

OBJECTIVES

Several studies report reduced aerobic capacity in patients with fibromyalgia (FM). The purpose of our study was to investigate whether a reduction in aerobic capacity in these patients is accompanied by alterations in metabolic rate and heart rate (HR) response.

METHOD

Twelve women with FM and 12 healthy controls (HCs) matched on sex and age, and with similar leisure time physical activity, participated in the study. All subjects performed an incremental submaximal cycle ergometer test to anaerobic threshold [AT; i.e. blood lactate concentration (bLa) ≥ 4 mmol/L], followed by a stepwise test to exhaustion to estimate maximal oxygen consumption (VO(2max)).

RESULTS

Oxygen consumption and workload were lower among patients than HCs both at AT and at termination of the VO(2max) test (p < 0.011 for all comparisons). Two patients (18%) and nine HCs (75%) reached VO(2max) criteria. The relationship between metabolic rate and workload did not differ between groups at exercise below AT. At exercise above AT, the metabolic rate increased disproportionally to workload in the patients. Although the patients had a higher anaerobic contribution to the total metabolic rate at the end of the submaximal test, the anaerobic contribution at the end of the maximal test did not differ between groups. HR responses were largely similar between groups.

CONCLUSIONS

The current study indicates that patients with FM have similar metabolic and cardiovascular responses to submaximal exercise as HCs. However, these patients have reduced ability to reach VO(2max) and a possible deficit in the metabolic system when exercising above the AT.

Minimum data elements for research reports on CFS

Chronic fatigue syndrome (CFS) is a debilitating condition that has received increasing attention from researchers in the past decade. However, it has become difficult to compare data collected in different laboratories due to the variability in basic information regarding descriptions of sampling methods, patient characteristics, and clinical assessments. The issue of variability in CFS research was recently highlighted at the NIH's 2011 State of the Knowledge of CFS meeting prompting researchers to consider the critical information that should be included in CFS research reports. To address this problem, we present our consensus on the minimum data elements that should be included in all CFS research reports, along with additional elements that are currently being evaluated in specific research studies that show promise as important patient descriptors for subgrouping of CFS. These recommendations are intended to improve the consistency of reported methods and the interpretability of reported results. Adherence to minimum standards and increased reporting consistency will allow for better comparisons among published CFS articles, provide guidance for future research and foster the generation of knowledge that can directly benefit the patient.

Autonomic dysfunction in women with fibromyalgia

Fibromyalgia (FM) is an idiopathic disease characterized by widespread pain and a myriad of symptoms. Symptoms are diverse and include not only pain but also anxiety, depression, orthostatic intolerance, and cold intolerance. While the etiology of FM is not fully understood, data have suggested that FM may stem from dysfunction of the autonomic nervous system. This dysfunction has been reported at rest, and after a physiological stressor such as exercise. However, few studies have examined the responses during exercise. This novel approach may shed some new light on the effect of exercise in women with FM.