Heart rate variability responses to cognitive stress in fibromyalgia are characterised by inadequate autonomous system stress responses: a clinical trial

Abstract

Fibromyalgia (FM) is associated with sympathetically dominant dysautonomia, but the connection between dysautonomia and FM symptoms is unclear. Dysautonomia can be analysed with heart rate variability (HRV) and it has been proposed that FM patients comprise subgroups with differing profiles of symptom severity. In our study, 51 female FM patients aged 18 to 65 years and 31 age-matched healthy female controls followed a 20-min protocol of alternating relaxation and cognitive stress (mental arithmetic). Heart rates and electrocardiograms were registered. The HRV measures of heart rate (HR), mean interval between heart beats (RRmean), root mean squared interval differences of successive beats (RMSSD), and the standard deviation of intervals between normal heart beats (SDNN) were analysed with generalized linear modelling. Features in HRV reactivity which differed between FM patients and controls were used to cluster the FM patients and cluster characteristics were analysed. FM patients had higher baseline HR (72.3 [SD 12.7] vs 64.5 [7.80], p < 0.001) and lower RRmean (0.844 [0.134] vs 0.934 [0.118], p = 0.002), compared with controls. They also reacted to repeated cognitive stress with an attenuated rise in HR (− 4.41 [95% CI − 7.88 to − 0.93], p = 0.013) and attenuated decrease of RRmean (0.06 [95 CI 0.03 to 0.09], p < 0.001), compared with controls. Clustering of FM patients by HRV reactivity resulted in three clusters characterised by (1) normal levels of HRV and HRV reactivity with low levels of depressive mood and anxiety, (2) reduced levels of HRV and impaired HRV reactivity with increased levels of depressive mood and high levels of anxiety, and (3) lowest HRV and most impaired HRV reactivity with the highest scores for depressive mood and anxiety. Our results show that FM patients have lower HRV than healthy controls and their autonomous reactions to cognitive stress are attenuated. Dysautonomia in FM associates with mood disturbance. Trial registration ClinicalTrials.gov (NCT03300635). Registered October 3 2017—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03300635.

Abnormal quantitative sudomotor axon reflex test results in patients with tinnitus as a possible indicator of small fiber neuropathy

“…Although the abnormalities in QSART results have not been studied in stress-related disorders, the effects of stress have been studied using HRV tests. HRV abnormalities have been observed in patients with fibromyalgia in response to stress ( 28 ). The association between stress and HRV abnormalities suggests abnormal sympathetic dominance ( 29 ).…”

Motor Dysfunctions in Fibromyalgia Patients: The Importance of Breathing

“…It has been suggested that patients with FM have higher sympathetic system activity than healthy subjects and that shallow breathing increases the response of the same autonomic system. 12,96,97 A correct inspiration stimulates the action of the vagus nerve (parasympathetic), while a non-exhaustive breath stimulates the type IV diaphragmatic afferents; a constant activation of the latter afferents could be speculated to cause the increase of the sympathetic system activity. 97,98 In patients with FM the vagus nerve volume (cross-sectional area) is decreased compared to healthy subjects (although not all literature states this information).…”

“… 99 It is no coincidence that among the indications that the clinician issues to the fibromyalgia patient, there is that of performing respiratory exercises. 9 , 12 …”

“…Often the fibromyalgic patient presents with different clinical pictures and comorbidities, such as diabetes, obesity, allergic rhinitis, small-fiber neuropathy, kinesiophobia, other rheumatological pathologies (hypermobility spectrum disorder, Ehlers-Danlos syndrome), intestinal dysfunctions (irritable bowel syndrome, celiac disease), neuromotor imbalance, vestibulocochlear disorders, Raynaud's phenomenon, orthostatic intolerance, pelvic floor dysfunction and sexual dysfunction, orofacial area dysfunction, loss of cervical lordosis. 3,[6][7][8][9][10][11][12][13][14][15] Another limit for the exhaustive clinical identification of the pathology could lie in categorizing a patient with fibromyalgia compared to a non-fibromyalgia person, as it is not an operation that always leads to taking into consideration all subgroups of patients with FM. 16 For example, it is not always feasible to explain the origin of pain or when fibromyalgia starts.…”

The Cognitive and Emotional Aspect in Fibromyalgia: The Importance of the Orofacial Sphere

“…For a correct diagnosis of FMS, two years can pass from the onset of symptoms, with a tendency to involve the female sex in this pathology with unclear boundaries [3]. Many overlapping symptoms, such as the concomitant occurrence of irritable bowel syndrome, interstitial cystitis, orthostatic intolerance, dry mouth, and dry eyes, Reynaud's syndrome, celiac disease, obesity, sexual dysfunction, glucose intolerance and diabetes, oral area dysfunction (pain and altered arthrokinetics of the temporomandibular joint, malocclusion), intestinal dysbiosis and Crohn's disease [7][8][9].…”