Smoking is associated with reduced leptin and neuropeptide Y levels and higher pain experience in patients with fibromyalgia

Environmental pollutants and phosphoinositide signaling in autoimmunity

Environmental pollution stands as one of the most critical challenges affecting human health, with an estimated mortality rate linked to pollution-induced non-communicable diseases projected to range from 20% to 25%. These pollutants not only disrupt immune responses but can also trigger immunotoxicity. Phosphoinositide signaling, a pivotal regulator of immune responses, plays a central role in the development of autoimmune diseases and exhibits high sensitivity to environmental stressors. Among these stressors, environmental pollutants have become increasingly prevalent in our society, contributing to the initiation and exacerbation of autoimmune conditions. In this review, we summarize the intricate interplay between phosphoinositide signaling and autoimmune diseases within the context of environmental pollutants and contaminants. We provide an up-to-date overview of stress-induced phosphoinositide signaling, discuss 14 selected examples categorized into three groups of environmental pollutants and their connections to immune diseases, and shed light on the associated phosphoinositide signaling pathways. Through these discussions, this review advances our understanding of how phosphoinositide signaling influences the coordinated immune response to environmental stressors at a biological level. Furthermore, it offers valuable insights into potential research directions and therapeutic targets aimed at mitigating the impact of environmental pollutants on the pathogenesis of autoimmune diseases. SYNOPSIS: Phosphoinositide signaling at the intersection of environmental pollutants and autoimmunity provides novel insights for managing autoimmune diseases aggravated by pollutants.

Association of serum leptin and ghrelin levels with smoking status on body weight: a systematic review and meta-analysis

Background and aims

Smoking cigarettes is a major global health problem that affects appetite and weight. The aim of this systematic review was to determine how smoking affected plasma leptin and ghrelin levels.

Methods

A comprehensive search of PubMed, Scopus, Web of Science, and Ovid was conducted using a well-established methodology to gather all related publications.

Results

A total of 40 studies were included in the analysis of 11,336 patients. The overall effect showed a with a mean difference (MD) of -1.92[95%CI; -2.63: -1.20] and p = 0.00001. Subgroup analysis by study design revealed significant differences as well, but with high heterogeneity within the subgroups (I2 of 82.3%). Subgroup by sex showed that there was a significant difference in mean difference between the smoking and non-smoking groups for males (MD = -5.75[95% CI; -8.73: -2.77], p = 0.0002) but not for females (MD = -3.04[95% CI; -6.6:0.54], p = 0.10). Healthy, pregnant, diabetic and CVD subgroups found significant differences in the healthy (MD = -1.74[95% CI; -03.13: -0.35], p = 0.01) and diabetic (MD = -7.69[95% CI, -1.64: -0.73], p = 0.03). subgroups, but not in the pregnant or cardiovascular disease subgroups. On the other hand, the meta-analysis found no statistically significant difference in Ghrelin serum concentration between smokers and non-smokers (MD = 0.52[95% CI, -0.60:1.63], p = 0.36) and observed heterogeneity in the studies (I2 = 68%).

Conclusion

This study demonstrates a correlation between smoking and serum leptin/ghrelin levels, which explains smoking's effect on body weight.

Systematic review registration

https://www.crd.york.ac.uk/ prospero/display_record.php, identifier (Record ID=326680).

Lifestyle risk factors of self-reported fibromyalgia in the Norwegian Women and Cancer (NOWAC) study

BACKGROUND

While the aetiology of fibromyalgia syndrome (FM) remains unknown, lifestyle factors have been linked to the disorder. However, there are few studies on the association between lifestyle factors and FM, thus we examine the risk of self-reported fibromyalgia given selected lifestyle factors.

METHODS

We used data from 75,485 participants in the Norwegian Women and Cancer study. Information on FM and the lifestyle factors body mass index (BMI), physical activity level, smoking status/intensity, and alcohol consumption were obtained from baseline and follow-up questionnaires. We used Cox proportional hazards model to calculate hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

After a median follow-up time of 10 years, we observed 2,248 cases of self-reported fibromyalgia. Overweight (BMI 25-29.9 kg/m2) and obese (BMI ≥ 30 kg/m2) women had a relative risk of 1.34 (95% CI 1.21-1.47) and 1.62 (95% CI 1.41-1.87), respectively, compared to women with normal weight (BMI 18.5-24.9 kg/m2). Very low physical activity level (1-2) was associated with a 31% higher risk of self-reported fibromyalgia (HR 1.31, 95% CI 1.09-1.57) when compared to moderate physical activity level (5-6). There was a strong dose-response relationship between smoking status/intensity and self-reported fibromyalgia (p for trend < 0.001). Compared with moderate alcohol consumption (4.0-10 g/day), the risk of self-reported FM was 72% (HR 1.72; 95% CI 1.45-2.03) higher among teetotallers, and 38% (HR 1.38, 95% CI 1.23-1.54) higher among those with low consumption (0.1-3.9 g/day).

CONCLUSIONS

Overweight and obesity, very low physical activity level, smoking, and alcohol consumption were associated with an increased risk of self-reported FM.

Glucose tolerance in fibromyalgia

OBJECTIVES

Fibromyalgia (FM) patients have an increased risk for glucose metabolism disturbances, and impaired glucose tolerance may be associated with symptom severity. Elevated levels of plasma lactate have been detected in FM patients. Both pyruvate and lactate are produced in glucose metabolism and reflect oxidative metabolism. The objective of our study was to analyse disturbances in glucose, pyruvate, or lactate metabolism in FM patients.

METHODS

We measured plasma levels of glucose, pyruvate, and lactate during an oral glucose tolerance test in 40 non-diabetic, female FM patients and 30 age- and gender-matched healthy controls.

RESULTS

FM patients showed a higher glycaemic response to the glucose load at 1 hour (F [1,68] = 10.4, P = .006) and 2 hours (F [1,68] = 7.80, P = .02), and higher glucose area under the curve (13.8 [SD 2.92] vs 11.6 [SD 2.31], P < .01), than healthy controls. Group differences were explained by higher body mass index and percentage of smokers among the FM patients. Pyruvate and lactate levels were similar in both groups.

DISCUSSION

Impaired glucose regulation in FM patients is likely not due to FM itself, but to associated lifestyle factors. Our results highlight the importance of assessing the glucose regulation status and the lifestyle factors affecting glucose regulation in FM patients for prevention or early treatment of diabetes and associated complications.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03300635).

Diagnostic Challenges and Management of Fibromyalgia

The World Health Organization regards chronic pain to be a public health concern. In clinical medicine, fibromyalgia (FM) is the most prevalent chronic widespread pain disease. In terms of impairment, consumption of health and social resources, and impact on primary and speciality care systems, it has reached worrisome proportions. This disease is frequently managed by primary care providers. Because of its intricacy, fibromyalgia diagnosis and treatment can be difficult. Fibromyalgia is a controversial condition. It might appear ill-defined in comparison to other pain conditions, with no clear knowledge of pathophysiology and hence no particular targeted therapy. This invariably sparks debates and challenges. There is no obvious cut-off point that distinguishes FM from non-FM. The diagnosis of fibromyalgia has been complicated by several factors, including patients' health-seeking behaviour, symptom identification, and physician labelling of the disease. Fibromyalgia is currently considered a centralized pain condition, according to research that has improved our understanding of its etiopathology. A multidisciplinary strategy combining pharmacological and non-pharmacological therapies based on a biopsychosocial paradigm can result in effective therapy. Cultural and psychosocial variables appear to be a recent development in fibromyalgia, and they appear to have a larger influence on physician diagnosis than severe symptom levels in FM patients. Although physicians rely on FM criteria as the only way to classify FM patients in research and clinical settings, some crucial elements of the diagnostic challenge of fibromyalgia remain unsolved - invalidation, psychosocial variables, and diverse illness manifestation are some examples. Beyond the existing constructional scores, physicians' judgment gained in real communicative contexts with patients, appears to be the only dependable route for a more accurate diagnosis for fibromyalgia. We have performed an exhaustive review of the literature using the keywords "Fibromyalgia", "challenges" and "diagnosis" in PubMed and Google Scholar indexes up to September 2021. This article aims to examine the causes, diagnosis, and current treatment protocols of FM, as well as discuss some continuing debates and diagnostic challenges which physicians face in accurately diagnosing fibromyalgia.

Relationship of leptin, growth hormone, and insulin-like growth factor levels with body mass index and disease severity in patients with fibromyalgia syndrome

OBJECTIVE

A high prevalence of obesity in fibromyalgia syndrome (FMS) predisposes patients to metabolic changes. It is not clear how the clinical manifestations of the disease affect metabolism. This study aimed to investigate leptin, growth hormone (GH), and insulin-like growth factor (IGF-1) levels in FMS, and their relationship with body mass index (BMI) and disease severity.

METHOD

This case-control study included 60 patients with FMS and 42 age- and sex-matched healthy controls. BMIs were recorded for all participants. The disease severity was assessed using the Fibromyalgia Impact Questionnaire (FIQ) and a visual analog scale (VAS). The serum levels of leptin, GH, and IGF-1 of all participants were measured using specific enzyme-linked immunosorbent assays.

RESULTS

Both groups had similar age (p = 0.058), sex (p = 0.25), and BMI (p = 0.29) distribution. The mean age of the FMS and the control groups was 40.7 ± 10.8 years and 36.2 ± 13.6 years, respectively. The mean BMI was 26.7 kg/m² in the FMS group. The GH (p = 0.037) and IGF-1 (p = 0.002) levels were statistically lower, and leptin (p = 0.002) levels were considerably higher in the FMS group than in the control group. The leptin values were positively correlated with age (p = 0.001; r = 0.386) and BMI (p < 0.001; r = 445). Insulin-like growth factor levels were negatively correlated with age (p < 0.001; r = - 0.605) and BMI (p < 0.001; r = - 0.564). Similarly, GH levels were negatively correlated with age (p = 0.040; r = - 0.243) and BMI (p < 0.001; p = - 0.420). None of the three hormones were associated with FIQ and VAS.

CONCLUSION

We found that leptin (high), GH (low), and IGF-1 (low) levels were statistically different, together with being independent of disease severity (FIQ, VAS), and correlated with BMI in the FMS group. These findings may be related with hypothalamo-pituitary axis dysfunction, BMI, and energy metabolism.

Role of inflammation in the pathogenesis and treatment of fibromyalgia

Fibromyalgia is a multifaceted disease. The clinical picture of fibromyalgia covers numerous comorbidities. Each comorbidity stands as a distinct condition. However, common pathophysiologic factors are occupied in their background. Along with the genetic, environmental and neuro-hormonal factors, inflammation has been supposed to have role in the pathogenesis of fibromyalgia. The aim of the present article was to review the current literature regarding the potential role of inflammation in the pathogenesis and treatment of fibromyalgia. A literature search was conducted through PubMed/MEDLINE and Web of Science databases using relevant keywords. Recent evidence on this highly studied topic indicates that fibromyalgia has an immunological background. Cytokines/chemokines, lipid mediators, oxidative stress and several plasma-derived factors underlie the inflammatory state in fibromyalgia. There are potential new therapeutic options targeting inflammatory pathways in fibromyalgia patients. In conclusion, there is evidence to support the inflammation-driven pathways in the pathogenesis of fibromyalgia. However, further research is required to fully understand the network of inflammation and its possible role in diagnosis and/or treatment of fibromyalgia.

Modulation of neural regulators of energy homeostasis, and of inflammation, in the pups of mice exposed to e-cigarettes

BACKGROUND

Maternal smoking can lead to perturbations in central metabolic regulators such as neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) signalling components in offspring. With the growing interest in e-cigarettes as a tobacco replacement, this short report assessed central metabolic regulation in offspring of mouse dams exposed to e-cigarettes. We examined the impact of continuous use of e-cigarettes, and e-cigarette replacement of tobacco cigarettes during pregnancy. Supplementation of an antioxidant l-carnitine was also co-used with tobacco cigarette in the mother to determine whether the impact of maternal tobacco smoking was oxidative stress driven.

METHODS

Balb/c mice were exposed to either nicotine-containing (E-cig18) or nicotine-free (E-cig0) e-cigarette aerosols or tobacco smoke (SE) prior to mating and until their pups were weaned. After mating, two SE sub-groups were changed to E-cig18 exposure (Replacement), or supplementation l-carnitine while SE was continued. Male offspring were studied at weaning age.

RESULTS

The offspring of E-cig0 dams were the heaviest with the most body fat. Replacing SE with E-cig18 during pregnancy resulted in offspring with significantly less body fat. E-cig0 offspring had significantly increased mRNA expression of brain NPY and iNOS. Maternal SE upregulated mRNA expression of NPY, NPY Y1 receptor, POMC downstream components, and iNOS expression, which were normalised in Replacement offspring, but only partially normalised with maternal L-carnitine supplementation during gestation and lactation.

CONCLUSIONS

Maternal exposure to either tobacco and nicotine-free e-cigarettes lead to disturbances in the level of central homeostatic control markers in offspring, suggesting that maternal exposure to e-cigarettes is not without risks.

The relationship between serum leptin level and disease activity and inflammatory markers in fibromyalgia patients

OBJECTIVE

The aim of this study was to investigate whether there is a correlation between serum leptin level, disease activity and inflammation markers in patients with fibromyalgia syndrome (FMS).

METHODS

A total of 48 patients with FMS diagnosed according to the 1990 American College of Rheumatology criteria were included in the study, as well as 36 healthy women as controls. The Visual Analogue Scale was used to gauge pain severity, the Fibromyalgia Impact Questionnaire was used to assess physical function, the 36-Item Short Form Health Survey was used to examine quality of life, and depression was measured with the Beck Depression Inventory. Blood samples were examined for erythrocyte sedimentation rate (ESR), C-reactive protein level (CRP), high-sensitivity CRP level (hsCRP), the neutrophil-to-lymphocyte ratio (NLR), and the serum leptin level was determined using the enzyme-linked immunosorbent assay method.

RESULTS

The serum leptin level in patients with FMS was significantly higher than in the healthy group. However, no significant relationship was found between leptin level and clinical and inflammatory parameters. In addition, there were no significant differences between the patients and the control group in measurements of ESR, CRP, hsCRP, or NLR.

CONCLUSION

A higher serum leptin level in patients with FMS suggested that leptin may play role in the pathogenesis of FMS, yet there was no relationship between leptin and clinical and inflammatory parameters, suggesting that leptin is not an indicator of disease activity in FMS. Additional research should be performed with larger patient groups.

The use of cerebrospinal fluid in biomarker studies

Cerebrospinal fluid (CSF) is an extremely useful matrix for biomarker research for several purposes, such as diagnosis, prognosis, monitoring, and identification of prominent leads in pathways of neurologic diseases. Such biomarkers can be identified based on a priori hypotheses around prominent protein changes, but also by applying -omics technologies. Proteomics is widely used, but metabolomics and transcriptomics are rapidly revealing their potential for CSF studies. The basis of such studies is the availability of high-quality biobanks. Furthermore, profound knowledge and consequent optimization of all aspects in biomarker development are needed. Here we discuss current knowledge and recently developed protocols for successful biomarker studies, from collection of CSF by lumbar puncture, processing, and biobanking protocols, preanalytic confounding factors, and cost-efficient development and validation of assays for implementation into clinical practice or research.

IGF-1R signalling contributes to IL-6 production and T cell dependent inflammation in rheumatoid arthritis

BACKGROUND

Signalling through insulin-like growth factor 1 receptor (IGF-1R) is essential for cell survival, but may turn pathogenic in uncontrolled tissue growth in tumours. In rheumatoid arthritis (RA), the IGF-1R signalling is activated and supports expansion of the inflamed synovia.

AIM

In the present study, we assess if disruption of IGF-1R signalling resolves arthritis.

MATERIAL AND METHODS

Clinical associations of IGF-1R expression in leukocytes of the peripheral blood were studied in 84 RA patients. Consequences of the IGF-1R signalling inhibition for arthritis were studied in mBSA immunised Balb/c mice treated with NT157 compound promoting degradation of insulin receptor substrates.

RESULTS

In RA patients, high expression of IGF-1R in leukocytes was associated with systemic inflammation as verified by higher expression of NF-kB, serum levels of IL6 and erythrocyte sedimentation rate, and higher pain perception. Additionally, phosphorylated IGF-1R and STAT3 enriched T cells infiltrate in RA synovia. Treatment with NT157 inhibited the phosphorylation of IGF-1R and STAT3 in synovia, and alleviated arthritis and joint damage in mice. It also reduced expression of IGF-1R and despaired ERK and Akt signalling in spleen T cells. This limited IL-6 production, changed RoRgt/FoxP3 balance and IL17 levels.

CONCLUSION

IGF-1R signalling contributes to T cell dependent inflammation in arthritis. Inhibition of IGF-1R on the level of insulin receptor substrates alleviates arthritis by restricting IL6-dependent formation of Th17 cells and may open for new treatment strategies in RA.

Is there a role for IGF-1 in the development of second primary cancers?

Cancer survival rates are increasing, and as a result, more cancer survivors are exposed to the risk of developing a second primary cancer (SPC). It has been hypothesized that one of the underlying mechanisms for this risk could be mediated by variations in insulin-like growth factor-1 (IGF-1). This review summarizes the current epidemiological evidence to identify whether IGF-1 plays a role in the development of SPCs. IGF-1 is known to promote cancer development by inhibiting apoptosis and stimulating cell proliferation. Epidemiological studies have reported a positive association between circulating IGF-1 levels and various primary cancers, such as breast, colorectal, and prostate cancer. The role of IGF-1 in increasing SPC risk has been explored less. Nonetheless, several experimental studies have observed a deregulation of the IGF-1 pathway, which may explain the association between IGF-1 and SPCs. Thus, measuring serum IGF-1 may serve as a useful marker in assessing the risk of SPCs, and therefore, more translational experimental and epidemiological studies are needed to further disentangle the role of IGF-1 in the development of specific SPCs.

Transmission pathways and mediators as the basis for clinical pharmacology of pain

INTRODUCTION

Mediators in pain transmission are the targets of a multitude of different analgesic pharmaceuticals. This review explores the most significant mediators of pain transmission as well as the pharmaceuticals that act on them. Areas covered: The review explores many of the key mediators of pain transmission. In doing so, this review uncovers important areas for further research. It also highlights agents with potential for producing novel analgesics, probes important interactions between pain transmission pathways that could contribute to synergistic analgesia, and emphasizes transmission factors that participate in transforming acute injury into chronic pain. Expert commentary: This review examines current pain research, particularly in the context of identifying novel analgesics, highlighting interactions between analgesic transmission pathways, and discussing factors that may contribute to the development of chronic pain after an acute injury.

Quantification and regulation of the adipokines resistin and progranulin in human cerebrospinal fluid

BACKGROUND

Adipokines bearing the potential to cross the blood-brain barrier (BBB) are promising candidates for the endocrine regulation of central nervous processes and of a postulated fat-brain axis. Resistin and progranulin concentrations in paired serum and cerebrospinal fluid (CSF) samples of patients undergoing neurological evaluation and spinal puncture were investigated.

MATERIALS AND METHODS

Samples of n = 270 consecutive patients with various neurological diseases were collected without prior selection. Adipokine serum and CSF concentrations were measured by enzyme-linked immunosorbent assay and serum and CSF routine parameters by standard procedures. Anthropometric data, medication and patient history were available.

RESULTS

Serum levels of resistin and progranulin were positively correlated among each other, with respective CSF levels, low-density lipoprotein cholesterol levels and markers of systemic inflammation. CSF resistin concentrations were generally low. Progranulin CSF concentrations and CSF/serum progranulin ratio were significantly higher in patients with infectious diseases, with disturbed BBB function and with elevated CSF cell count and presence of oligoclonal bands. Both adipokines are able to cross the BBB depending on a differing patency that increases with increasing grade of barrier dysfunction. Whereas resistin represents a systemic marker of inflammation, CSF progranulin levels strongly depend on the underlying disease and dysfunction of blood-CSF barrier.

CONCLUSIONS

Resistin and progranulin represent novel and putative regulators of the fat-brain axis by their ability to cross the BBB under physiological and pathophysiological conditions. The presented data provide insight into the characteristics of BBB function regarding progranulin and resistin and the basis for future establishment of normal values for CSF concentrations and CSF/serum ratios.

Circulating leptin and pain perception among tobacco-dependent individuals

Recent preclinical evidence suggests that leptin may modulate the stress response and may increase nociception. In this study, we examined for the first time the extent to which cigarette smoking is associated with leptin levels during an extended rest period and in response to noxious stimuli. Repeated blood samples were collected during a laboratory session from smokers and nonsmokers and assayed for leptin. Pain experiences, as well as neuroendocrine and cardiovascular measures, were collected across cold pressor and thermal heat pain tests. Both analysis of variance and correlations confirmed that smokers demonstrated dysregulations in leptin responsivity and association with pain relative to nonsmokers. The flat pattern of leptin release and the weak associations of this hormone with pain in smokers suggest a long-term effect of tobacco dependence on this regulatory hormone. In light of leptin's influence on reward pathways, further investigation of leptin's involvement in nicotine dependence is warranted.