Exploring Genetic Susceptibility to Fibromyalgia

Neuronutritional Approach to Fibromyalgia Management: A Narrative Review

Fibromyalgia (FM) is a complex and common syndrome characterized by chronic widespread pain, fatigue, sleep disturbances, and various functional symptoms without clear structural or pathological causes. Affecting approximately 1-5% of the global population, with a higher prevalence in women, FM significantly impacts patients' quality of life, often leading to considerable healthcare costs and loss of productivity. Despite its prevalence, the etiology of FM remains elusive, with genetic, environmental, and psychological factors, including nutrition, being implicated. Currently, no universally accepted treatment guidelines exist, and management strategies are often symptomatic. This narrative review explores the potential of a neuronutritional approach to FM management. It synthesizes existing research on the relationship between FM and nutrition, suggesting that dietary interventions could be a promising complementary treatment strategy. Various nutritional interventions, including vitamin D, magnesium, iron, and probiotics supplementation, have shown potential in reducing FM symptoms, such as chronic pain, anxiety, depression, cognitive dysfunction, sleep disturbances, and gastrointestinal issues. Additionally, weight loss has been associated with reduced inflammation and improved quality of life in FM patients. The review highlights the anti-inflammatory benefits of plant-based diets and the low-FODMAPs diet, which have shown promise in managing FM symptoms and related gastrointestinal disorders. Supplements such as vitamin D, magnesium, vitamin B12, coenzyme Q10, probiotics, omega-3 fatty acids, melatonin, S-adenosylmethionine, and acetyl-L-carnitine are discussed for their potential benefits in FM management through various mechanisms, including anti-inflammatory effects, modulation of neurotransmitters, and improvement of mitochondrial function. In conclusion, this review underscores the importance of considering neuronutrition as a holistic approach to FM treatment, advocating for further research and clinical trials to establish comprehensive dietary guidelines and to optimize management strategies for FM patients.

Nutraceutical Supplementation as a Potential Non-Drug Treatment for Fibromyalgia: Effects on Lipid Profile, Oxidative Status, and Quality of Life

Fibromyalgia (FM) is a chronic syndrome of unknown etiology, although many studies point to inflammation, oxidative stress, and altered mitochondrial metabolism as some of the cornerstones of this disease. Despite its socioeconomic importance and due to the difficulties in diagnosis, there are no effective treatments. However, the use of non-drug treatments is increasingly becoming a recommended strategy. In this context, the effects of supplementation of FM patients with an olive (poly)phenol, vitamin C, and vitamin B preparation were investigated in this work, analyzing complete blood count, biochemical, lipid, and coagulation profiles, and inflammation and oxidation status in blood samples. To gain a better understanding of the molecular mechanisms and pathways involved in the etiology of FM, a proteomic study was also performed to investigate the mechanisms of action of the supplement. Our results show that the nutraceutical lowers the lipid profile, namely cholesterol, and improves the oxidative status of patients as well as their quality of life, suggesting that this product could be beneficial in the co-treatment of FM. ClinicalTrials.gov (ID: NCT06348537).

Pain Biomarkers in Fibromyalgia Syndrome: Current Understanding and Future Directions

Fibromyalgia is a complex and heterogeneous clinical syndrome, mainly characterized by the presence of widespread pain, possibly associated with a variety of other symptoms. Fibromyalgia can have an extremely negative impact on the psychological, physical and social lives of people affected, sometimes causing patients to experience dramatically impaired quality of life. Nowadays, the diagnosis of fibromyalgia is still clinical, thus favoring diagnostic uncertainties and making its clear identification challenging to establish, especially in primary care centers. These difficulties lead patients to undergo innumerable clinical visits, investigations and specialist consultations, thus increasing their stress, frustration and even dissatisfaction. Unfortunately, research over the last 25 years regarding a specific biomarker for the diagnosis of fibromyalgia has been fruitless. The discovery of a reliable biomarker for fibromyalgia syndrome would be a critical step towards the early identification of this condition, not only reducing patient healthcare utilization and diagnostic test execution but also providing early intervention with guideline-based treatments. This narrative article reviews different metabolite alterations proposed as possible biomarkers for fibromyalgia, focusing on their associations with clinical evidence of pain, and highlights some new, promising areas of research in this context. Nevertheless, none of the analyzed metabolites emerge as sufficiently reliable to be validated as a diagnostic biomarker. Given the complexity of this syndrome, in the future, a panel of biomarkers, including subtype-specific biomarkers, could be considered as an interesting alternative research area.

Lower limb muscle strength and serotonin receptor gene polymorphism as factors associated in women with fibromyalgia

BACKGROUND

Fibromyalgia (FM) is a chronic pain syndrome characterized by generalized skeletal muscle chronic pain. Its etiology is not well defined, because there are several factors that may trigger it such as physical and/or emotional stresses, or a genetic susceptibility, involving serotonergic, dopaminergic and catecholaminergic paths. The objective of this study was to investigate the association between the strength of the lower limb, genetic polymorphism of the serotonin receptor gene HTR_2A in women with fibromyalgia.

METHODS

In this observational study of case-control type 48 women were evaluated who belonged to the group with FM (52 ± 12 years) and 100 women in the control group (58 ± 11 years). Socio demographic and anthropometric data were collected and peripheral blood samples for DNA extraction; genotypic analyzes were performed by means of PCR in real time by TaqMan® system. The lower limb muscle strength was assessed through the test of sitting down and standing up for 30 s. The chi-square test or Fischer Exact was used for possible associations among the variables; the t-test for independent samples was used to compare the averages among the groups; the value of significance adopted was 5%.

RESULTS

There was an association between the polymorphism of the HTR2A gene with FM, demonstrating that carriers of the genotype GG have 24.39 times more likely to develop the syndrome (IC95% 5.15-115.47; p = 0.01). It was observed an association between FM and the test to sit and stand up demonstrating that women with fibromyalgia have lower limb muscle strength (p = 0.01). The study showed that the white race has 3.84 times more likely to develop FM (p = 0.01).

CONCLUSION

The results of this study suggest that women of Caucasian ethnicity with GG genotype or G allele presented greater risk of developing fibromyalgia and that these patients have lower limb muscle strength compared to the control group.

Chronic Widespread Pain and Fibromyalgia Syndrome: Life-Course Risk Markers in Young People

Although the life-course concept of risk markers as potential etiological influences is well established in epidemiology, it has not featured in academic publications or clinical practice in the context of chronic widespread pain (CWP) and fibromyalgia syndrome (FMS). Studies of risk markers are required considerations for evaluation of patients and for research because there is no single cause, pathological feature, laboratory finding, or biomarker for CWP or FMS. The early-life risk markers identified by extensive literature review with best evidence for potential causal influence on the development and progression of CWP and FMS include genetic factors, premature birth, female sex, early childhood adversity, cognitive and psychosocial influences, impaired sleep, primary pain disorders, multiregional pain, physical trauma, infectious illness, obesity and inactivity, hypermobility of joints, iron deficiency, and small-fiber polyneuropathy. The case history illustrates the potential etiological influence of multiple risk markers offset by personal resilience.

The Role of Genetic Polymorphisms in Chronic Pain Patients

It is estimated that the total annual financial cost for pain management in the U.S. exceeds 100 billion dollars. However, when indirect costs are included, such as functional disability and reduction in working hours, the cost can reach more than 300 billion dollars. In chronic pain patients, the role of pharmacogenetics is determined by genetic effects on various pain types, as well as the genetic effect on drug safety and efficacy. In this review article, we discuss genetic polymorphisms present in different types of chronic pain, such as fibromyalgia, low back pain, migraine, painful peripheral diabetic neuropathy and trigeminal neuralgia. Furthermore, we discuss the role of CYP450 enzymes involved in metabolism of drugs, which have been used for treatment of chronic pain (amitriptyline, duloxetine, opioids, etc.). We also discuss how pharmacogenetics can be applied towards improving drug efficacy, shortening the time required to achieve therapeutic outcomes, reducing risks of side effects, and reducing medical costs and reliance upon polypharmacy.

Genome-wide methylation analysis of a large population sample shows neurological pathways involvement in chronic widespread musculoskeletal pain

Chronic widespread musculoskeletal pain (CWP), has a considerable heritable component, which remains to be explained. Epigenetic factors may contribute to and account for some of the heritability estimate. We analysed epigenome-wide methylation using MeDIPseq in whole blood DNA from 1708 monozygotic and dizygotic Caucasian twins having CWP prevalence of 19.9%. Longitudinally stable methylation bins (lsBINs), were established by testing repeated measurements conducted ≥3 years apart, n = 292. DNA methylation variation at lsBINs was tested for association with CWP in a discovery set of 50 monozygotic twin pairs discordant for CWP, and in an independent dataset (n = 1608 twins), and the results from the 2 samples were combined using Fisher method. Functional interpretation of the most associated signals was based on functional genomic annotations, gene ontology, and pathway analyses. Of 723,029 signals identified as lsBINs, 26,399 lsBINs demonstrated the same direction of association in both discovery and replication datasets at nominal significance (P ≤ 0.05). In the combined analysis across 1708 individuals, whereas no lsBINs showed genome-wide significance (P < 10-8), 24 signals reached p≤9E-5, and these included association signals mapping in or near to IL17A, ADIPOR2, and TNFRSF13B. Bioinformatics analyses of the associated methylation bins showed enrichment for neurological pathways in CWP. We estimate that the variance explained by epigenetic factors in CWP is 6%. This, the largest study to date of DNA methylation in CWP, points towards epigenetic modification of neurological pathways in CWP and provides proof of principle of this method in teasing apart the complex risk factors for CWP.

Gray matter abnormalities associated with fibromyalgia: A meta-analysis of voxel-based morphometric studies

OBJECTIVES

Studies employing voxel-based morphometry (VBM) have reported inconsistent findings on the association of gray matter (GM) abnormalities with fibromyalgia. The aim of the present study is to identify the most prominent and replicable GM areas that involved in fibromyalgia.

METHODS

A systematic search of the PubMed database from January 2000 to September 2015 was performed to identify eligible whole-brain VBM studies. Comprehensive meta-analyses to investigate regional GM abnormalities in fibromyalgia were conducted with the Seed-based d Mapping software package.

RESULTS

Seven studies, reporting nine comparisons and including a grand total of 180 fibromyalgia patients and 126 healthy controls, were included in the meta-analyses. In fibromyalgia patients compared with healthy controls, regional GM decreases were consistently found in the bilateral anterior cingulate/paracingulate cortex/medial prefrontal cortex, the bilateral posterior cingulate/paracingulate cortex, the left parahippocampal gyrus/fusiform cortex, and the right parahippocampal gyrus/hippocampus. Regional GM increases were consistently found in the left cerebellum. Meta-regression demonstrated that age was correlated with GM anomalies in fibromyalgia patients.

CONCLUSIONS

The current meta-analysis identified a characteristic pattern of GM alterations within the medial pain system, default mode network, and cerebro-cerebellar circuits, which further supports the concept that fibromyalgia is a symptom complex involving brain areas beyond those implicated in chronic pain.