Arginase, NOS Activities, and Clinical Features in Fibromyalgia Patients

Evaluation of Endothelial Dysfunction and Autophagy in Fibromyalgia-Related Vascular and Cerebral Cortical Changes and the Ameliorative Effect of Fisetin

Fibromyalgia (FM) is a common chronic pain syndrome that affects 1% to 5% of the population. We aimed to investigate the role of endothelial dysfunction and autophagy in fibromyalgia-related vascular and cerebral cortical changes in a reserpine-induced rat model of fibromyalgia at the histological and molecular levels and to study the ameliorative effect of fisetin. Forty adult female albino rats were divided into four groups (10 each): two control groups, the reserpine-induced fibromyalgia group, and the fisetin-treated group. The carotid arteries and brains of the animals were dissected. Frozen tissue samples were used for total RNA extraction and qPCR analysis of eNOS, caspase-3, Bcl-2, LC-3, BECN-1, CHOP, and TNF-α expression. Histological, immunohistochemical (eNOS), and ultrastructure studies were conducted. The carotid arteries revealed excessive autophagy and endothelial, vascular, and apoptotic changes. The cerebral cortex showed similar findings apart from endoplasmic reticulum stress. Additionally, there was decreased gene expression of eNOS and Bcl-2 and increased expression of caspase-3, LC-3, BECN-1, CHOP, and TNF-α. In the fisetin-treated rats, improvements in the histological and molecular results were detected. In conclusion, oxidative stress, enhanced apoptosis, and excessive autophagy are fundamental pathophysiologic mechanisms of reserpine-induced fibromyalgia. Moreover, fisetin has an ameliorative effect against fibromyalgia.

Metal-induced oxidative stress level in patients with fibromyalgia syndrome and its contribution to the severity of the disease: A correlational study

BACKGROUND

Fibromyalgia syndrome (FMS) is an extra-articular rheumatological disease characterised by widespread chronic musculoskeletal pain. Metal-induced oxidative stress contributes to the severity of FMS.

AIMS

First, this study evaluated the association between plasma levels of toxic heavy metals and essential metals with oxidative stress (OS) markers. Second, the OS markers and metal contents were correlated with the disease severity by assessing the Fibromyalgia Impact Questioner Revised (FIQR) and tender points (TP).

METHOD

A total of 105 FMS patients and 105 healthy controls of similar age and sex were recruited. OS parameter such as lipid peroxidation (LPO), protein carbonyl group (PCG), nitric oxide (NO) and essential metals such as zinc (Zn), magnesium (Mg), manganese (Mn), copper (Cu) and toxic heavy metals such as aluminium (Al), arsenic (As), lead (Pb) were estimated.

RESULTS

Levels of LPO, PCG, NO (p< 0.001) and Cu, Mn, and Al (p< 0.001), were significantly higher, and Mg (p< 0.001) and Zn (p< 0.001) were significantly lower in patients compared to controls. A positive association was observed between OS parameters, FIQR and TP with Cu, Al and Mn. A significant negative association was observed between Zn and Mg with FIQR, TP and OS parameters.

CONCLUSION

Heavy metals such as Al induce OS parameters and decrease the levels of essential trace elements such as Mg and Zn, which may be responsible for the severity of FMS.

Associations Among Nitric Oxide and Enkephalinases With Fibromyalgia Symptoms

BACKGROUND

Fibromyalgia (FM) is a complex syndrome of uncertain etiology, characterized by the presence of widespread pain. Both nitric oxide and enkephalinases modulate pain perception.

OBJECTIVES

The aim of this study was to evaluate the relationships among serum nitric oxide levels, oxytocinase activity, and enkephalin-degrading aminopeptidase (EDA) activity with pain-related clinical manifestations in women with FM.

METHODS

We performed an observational case study in a population of 58 women diagnosed with FM. Serum nitric oxide levels were analyzed by an ozone chemiluminescence-based assay. Both serum oxytocinase and EDA activities were fluorometrically determined. Pain threshold and pain magnitude were evaluated using the PainMatcher. The pressure pain thresholds were measured using a digital pressure algometer. We used a visual analog scale, the Central Sensitization Inventory, the Revised Fibromyalgia Impact Questionnaire, and the Beck Anxiety Inventory to assess the global level of pain, the symptoms associated with the central sensitization syndrome, the severity of FM, and the anxiety level, respectively.

RESULTS

Multiple linear regression analysis adjusted by age, body mass index, and menopause status revealed significant associations between nitric oxide levels and dominant occiput pressure pain thresholds, nondominant occiput pressure pain thresholds, and FM effects. Significant associations of oxytocinase activity with the visual analog scale and dominant knee pressure pain thresholds were also found. Moreover, results showed a significant association between high EDA activity levels and dominant second-rib pressure pain thresholds.

DISCUSSION

Our data have shown significant relationships of serum nitric oxide levels and oxytocinase and EDA activities with some body pressure pain thresholds, the daily activity level, and the global intensity of pain in women with FM. These results suggest that pain, which is the main symptom of this syndrome, may be related to alterations in nitric oxide levels and in oxytocinase and EDA activities in patients with FM.

Evaluation of sympathetic adrenergic branch of cutaneous neural control throughout thermography and its relationship to nitric oxide levels in patients with fibromyalgia

BACKGROUND

Fibromyalgia syndrome is defined as a complex disease, characterized by chronic widespread musculoskeletal pain and other symptoms. The factors underlying physiopathology of fibromyalgia are not well understood, complicating its diagnosis and management.

OBJECTIVES

To evaluate the peripheral vascular blood flow of the skin of the hands and the core body temperature as indirect measures of sympathetic adrenergic activity of the nervous system and its relationship to nitric oxide levels (NO) in women with fibromyalgia compared with healthy controls.

METHODS

Forty-two women with fibromyalgia and 52 healthy women were enrolled in this observational pilot study. We used infrared thermography of the hands and an infrared dermal thermometer to evaluate the peripheral vascular blood flow and tympanic and axillary core body temperature, respectively. We measured NO levels using the ozone chemiluminescence-based method.

RESULTS

Two-way analysis of covariance (ANCOVA) showed that the tympanic (P=0.002) and hand temperatures were significantly higher in the patients with fibromyalgia than in the controls (P≤0.001). Significant associations were also found between serum NO levels and minimum temperatures at the dorsal center of the dominant hand (β=-3.501; 95% confidence interval [CI] -6.805, ‑0.198; P= 0.038), maximum temperature (β=-5.594; 95% CI ‑10.106, ‑1.081; P=0.016), minimum temperature (β=-4.090; 95% CI ‑7.905, ‑0.275; P=0.036), and mean temperature (β=-5.519; 95% CI ‑9.933, ‑1.106; P=0.015) of the center of the palm of the non-dominant hand, maximum temperature at the thenar eminence of the dominant hand (β=-5.800; 95% CI ‑10.508, ‑1.092; P=0.017), and tympanic temperature (β=-9.321; 95% CI ‑17.974, ‑0.669; P=0.035) in the controls.

CONCLUSIONS

Our findings indicate that the women with fibromyalgia showed higher tympanic core body and hand temperature than the healthy controls. Moreover, there were negative associations between hand peripheral vasodilation and NO in the healthy women but not in those with fibromyalgia, suggesting a dysfunction of sympathetic cutaneous neural control.

Sedentary Time Accumulated in Bouts is Positively Associated with Disease Severity in Fibromyalgia: The Al-Ándalus Project

To examine the associations of prolonged sedentary time (ST) with disease severity in women with fibromyalgia, and to analyse the combined association of total ST and prolonged ST with the disease severity in this population. Women (n = 451; 51.3 ± 7.6 years old) with fibromyalgia participated. Sedentary time and moderate-to-vigorous physical activity (MVPA) were measured using triaxial accelerometry and ST was processed into 30- and 60-min bouts. Dimensions of fibromyalgia (function, overall, symptoms) and the overall disease impact were assessed with the Revised Fibromyalgia Impact Questionnaire (FIQR). Body fat percentage was assessed using a bio-impedance analyser, and physical fitness was assessed with the Senior Fitness Tests Battery. Greater percentage of ST in 30-min bouts and 60-min bouts were associated with worse function, overall, symptoms and the overall impact of the disease (all, P < 0.05). Overall, these associations were statistically significant when additionally controlling for MVPA and overall physical fitness. Participants with low levels of total ST and prolonged ST (>60-min bouts) presented lower overall impact compared to participants with high levels of total ST and prolonged ST (mean difference = 6.56; 95% confidence interval (CI) = 1.83 to 11.29, P = 0.002). Greater percentage of ST accumulated in 30- and 60-min bouts and a combination of high levels of total and prolonged ST are related to worse disease severity. Although unable to conclude on causality, results suggest it might be advisable to motivate women with fibromyalgia to break prolonged ST and reduce their total daily ST.

Ambroxol for the treatment of fibromyalgia: science or fiction?

Fibromyalgia appears to present in subgroups with regard to biological pain induction, with primarily inflammatory, neuropathic/neurodegenerative, sympathetic, oxidative, nitrosative, or muscular factors and/or central sensitization. Recent research has also discussed glial activation or interrupted dopaminergic neurotransmission, as well as increased skin mast cells and mitochondrial dysfunction. Therapy is difficult, and the treatment options used so far mostly just have the potential to address only one of these aspects. As ambroxol addresses all of them in a single substance and furthermore also reduces visceral hypersensitivity, in fibromyalgia existing as irritable bowel syndrome or chronic bladder pain, it should be systematically investigated for this purpose. Encouraged by first clinical observations of two working groups using topical or oral ambroxol for fibromyalgia treatments, the present paper outlines the scientific argument for this approach by looking at each of the aforementioned aspects of this complex disease and summarizes putative modes of action of ambroxol. Nevertheless, at this point the evidence basis for ambroxol is not strong enough for clinical recommendation.

Microvascular functions in patients with fibromyalgia syndrome: effects of physical exercise

Objectives

This study aims to evaluate the current state of microvascular function and to investigate the effect of supervised aerobic exercise on microvascular control mechanisms and health outcomes in women with fibromyalgia syndrome (FMS).

Patients and methods

Forty female patients (mean age 51±11 years) with a diagnosis of FMS according to the American College of Rheumatology criteria and 20 healthy female controls (mean age 52±9 years) were included in the study. Microvascular blood flow was measured using a laser Doppler flowmeter (LDF) at the volar skin site of the forearm. Pain severity and FMS were assessed using the visual analog scale (VAS) and Fibromyalgia Impact Questionnaire (FIQ), respectively, both at the beginnig and at the end of the study. Fibromyalgia was evaluated and a spectral analysis of LDF signals was carried out to assess the relative contribution of each control mechanisms. The local thermal hyperemia was used to test the microvascular functions. Moderate-intensity aerobic activity (energy expenditure 3.0 to 6.0 metabolic equivalent) was performed by treadmill walking for 30 min for five days each week for a month.

Results

The patients with FMS had lower VAS and FIQ scores at the end of the exercise period. There was a positive correlation between improved myogenic and neurogenic mechanisms and reduced FIQ scores. Cardiac signals were positively correlated with the FIQ scores at the end of the exercise period. Endothelial function was under the influence of pain, and baseline nitric oxide activity was found to be positively correlated with VAS.

Conclusion

Our study results suggest that microvascular functions are impaired in FMS patients and moderate exercise training is effective to improve the FIQ/VAS scores and enhance vascular functions.