Serum levels of nitric oxide and cytokines in smokers at the beginning and after 4months of treatment for smoking cessation

Unveiling causal relationships between addiction phenotypes and inflammatory cytokines: insights from bidirectional mendelian randomization and bibliometric analysis

Observational studies have suggested associations between multiple inflammatory factors and tobacco and alcohol use, but establishing causation is challenging in epidemiological investigations. We employed genetic association data about the circulating levels of 41 cytokines obtained from the genome-wide association study (GWAS), which contained 8293 Finnish participants. Genetic data on 5 substance use phenotypes were obtained from the GWAS dataset containing 1.2 million European subjects. Then, we conducted a bidirectional mendelian randomization (MR) study. The forward results indicated that smoking cessation was positively correlated with hepatocyte growth factor (HGF), interleukin-10 (IL-10), and stem cell factor (SCF); cigarettes per day was a risk factor associated with high expression in stromal cell-derived factor 1α (SDF-1 A), interferon-γ (IFN-G), IL-4, and granulocyte colony-stimulating factor (G-CSF); drinks per week and smoking initiation were risk factors respectively correlated with reduced HGF and IL-2RA levels. During inverse MR analysis, the findings revealed that both IL-16 and IL-18 increased the risk of cigarettes per day; macrophage inflammatory protein-1β (MIP-1B) and tumor necrosis factor-β (TNF-B) inhibited and promoted smoking cessation, respectively; macrophage colony-stimulating factor (M-CSF) elevated the risk of drinks per week, while interferon inducible protein 10 (IP-10) had a contrary role; IL-7 and M-CSF respectively prolonged and shortened age of initiation of regular smoking. This study provides genetic proof supporting a causal relationship between various inflammatory factors and addiction phenotypes. Further comprehensive investigations are required to uncover underlying biological mechanisms. In addition, bibliometric studies have shown that oxidative stress is one of the most important orientations in alcohol and tobacco addiction research, where an in-depth investigation of its pro-inflammatory mechanisms would facilitate the development of potential therapeutic biological targets and drugs.

Evaluation of serum nitric oxide synthase levels in patients with coronary slow flow based on corrected TIMI frame count

Introduction

The coronary slow flow phenomenon (CSFP) finding in angiography is characterized by the delayed filling of the terminal vessels without significant epicardial coronary disease. The endothelium performs a vital role in cardiovascular homeostasis by releasing vasoactive substances. Endothelial cells produce nitric oxide (NO) as one of these essential compounds. Three isoforms of nitric oxide synthase (NOS) are endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), and induced nitric oxide synthase (iNOS). We aimed to determine the role of NOS in the development of CSFP as the first human study.

Material and methods

A total of 129 patients who met the inclusion criteria were enrolled in the study. The patients were classified into five groups based on the results of coronary angiography: Group 1 without coronary artery disease (CAD) and without CSF, group 2 without CAD and with CSF, group 3 with CAD (< 50%) and without CSF, group 4 with CAD (50-90%) and without CSF, and group 5 with CAD and CSF. The serum level of NOS was determined in the participants. Coronary flow was quantified in patients with CSFP using the corrected TIMI frame count (CTFC) method, and the correlation between the levels of this biomarker and CTFC was investigated.

Results

In this study, the NOS serum levels were not significantly correlated with the mean CTFC. Since the total amount of NOS was measured as a result of 3 isoforms of this enzyme, the lack of correlation could be related to increased iNOS level and decreased eNOS concentration.

Conclusions

These results should be confirmed by more human studies.

Peripheral blood cytokines as potential diagnostic biomarkers of suicidal ideation in patients with first-episode drug-naïve major depressive disorder

Objective

Major Depressive Disorder (MDD) is a leading cause of disability, with a high risk of suicidal ideation (SI). Few studies have evaluated the potential of multiple cytokines as biomarkers for SI in patients with MDD. In the present study, we examined the serum levels of multiple cytokines in patients with first-episode drug-naïve MDD, with the aim to discover and identify serum cytokines-based biomarkers for identification of SI in MDD.

Methods

A total of 55 patients with first-episode drug-naïve MDD were enrolled and divided into two groups: 26 MDD patients without SI and 29 MDD patients with SI. Beck Scale for Suicide Ideation was used to estimate SI. A total of 37 cytokines were measured using Multiplex Luminex Assays. The levels of serum cytokines between MDD patients without SI and MDD patients with SI were compared and diagnostic values of different cytokines were evaluated using the receiver operating characteristic (ROC) curve method for discriminating MDD patients with SI from MDD patients without SI. The relationship between the group and the abnormal cytokines were investigated in multiple linear regression models, with adjustments for age, gender, BMI, smoking, and Hamilton Depression Rating Scale-24 (HAMD-24) scores.

Results

The levels of CCL26 and VEGF in MDD patients with SI were significantly lower than those in MDD patients without SI (all P < 0.05). On the contrary, the levels of IL-17C, CXCL10, and TNF-β in MDD patients with SI were significantly higher than those in MDD patients without SI (all P < 0.05). Moreover, the results of multiple linear regression revealed that group was a significant independent predictor of serum IL-17C, CCL-26, VEGF, and TNF-β levels (all P < 0.05). In terms of CXC10, group was also likely to be a significant independent predictor (β = 0.257, P = 0.063). Furthermore, the AUC values of IL-17C and TNF-β were 0.728 and 0.732, respectively. Additionally, a combined panel of IL-17C and TNF-β achieved a high accuracy in discriminating MDD patients with SI from MDD patients without SI (AUC = 0.848, sensitivity = 75.9%, specificity = 72.7%).

Conclusions

These results suggested that circulating IL-17C and TNF-β may hold promise in the discovery of biomarkers for identification of SI in MDD.

Common Risk Factor Approach to Limit Noncommunicable Diseases and Periodontal Disease-The Molecular and Cellular Basis: A Narrative Review

Introduction

The link between periodontal disease and noncommunicable diseases (NCDs) has been the subject of major research over the past several years. The primary objective of this review is to understand the cellular and molecular components that link common risk factors (exposure) in adult patients (population) with periodontal disease and other NCDs (outcome). The secondary objective is to interpret from existing literature the possibility of identifying the molecular plausibility of the Common Risk Factor Approach (CRFA).

Materials and Methods

A literature search was performed in PubMed/MEDLINE, CINAHL, Web of Science, and Google Scholar for all published articles pertaining to the molecular and cellular basis of the risk factors between periodontal diseases and major NCDs. Data from all randomized and nonrandomized clinical trials, cross-sectional studies, case-control, cohort studies, literature, and systematic reviews were included.

Results

Periodontal pathogens, stress, obesity, smoking, and dietary factors are some of the common risk factors between periodontal disease and NCDs.

Conclusion

Understanding the molecular and cellular link of common risk factors between NCDs and periodontal disease would ensure the application of CRFA. The CRFA implies that controlling the risk factors associated with NCDs can have an incredible positive impact on regulating many chronic conditions, which would extend to periodontal health also.

Predictive Modeling of Thoracic Radiotherapy Toxicity and the Potential Role of Serum Alpha-2-Macroglobulin

Background: To investigate the impact of alpha-2-macroglobulin (A2M), a suspected intrinsic radioprotectant, on radiation pneumonitis and esophagitis using multifactorial predictive models. Materials and Methods: Baseline A2M levels were obtained for 258 patients prior to thoracic radiotherapy (RT). Dose-volume characteristics were extracted from treatment plans. Spearman's correlation (Rs) test was used to correlate clinical and dosimetric variables with toxicities. Toxicity prediction models were built using least absolute shrinkage and selection operator (LASSO) logistic regression on 1,000 bootstrapped datasets. Results: Grade ≥2 esophagitis and pneumonitis developed in 61 (23.6%) and 36 (14.0%) patients, respectively. The median A2M level was 191 mg/dL (range: 94-511). Never/former/current smoker status was 47 (18.2%)/179 (69.4%)/32 (12.4%). We found a significant negative univariate correlation between baseline A2M levels and esophagitis (Rs = -0.18/p = 0.003) and between A2M and smoking status (Rs = 0.13/p = 0.04). Further significant parameters for grade ≥2 esophagitis included age (Rs = -0.32/p < 0.0001), chemotherapy use (Rs = 0.56/p < 0.0001), dose per fraction (Rs = -0.57/p < 0.0001), total dose (Rs = 0.35/p < 0.0001), and several other dosimetric variables with Rs > 0.5 (p < 0.0001). The only significant non-dosimetric parameter for grade ≥2 pneumonitis was sex (Rs = -0.32/p = 0.037) with higher risk for women. For pneumonitis D15 (lung) (Rs = 0.19/p = 0.006) and D45 (heart) (Rs = 0.16/p = 0.016) had the highest correlation. LASSO models applied on the validation data were statistically significant and resulted in areas under the receiver operating characteristic curve of 0.84 (esophagitis) and 0.78 (pneumonitis). Multivariate predictive models did not require A2M to reach maximum predictive power. Conclusion: This is the first study showing a likely association of higher baseline A2M values with lower risk of radiation esophagitis and with smoking status. However, the baseline A2M level was not a significant risk factor for radiation pneumonitis.

Bidirectional Associations among Nicotine and Tobacco Smoke, NeuroHIV, and Antiretroviral Therapy

People living with HIV (PLWH) in the antiretroviral therapy (ART) era may lose more life-years to tobacco use than to HIV. Yet, smoking rates are more than twice as high among PLWH than the general population, contributing not just to mortality but to other adverse health outcomes, including neurocognitive deficits (neuroHIV). There is growing evidence that synergy with chronic inflammation and immune dysregulation that persists despite ART may be one mechanism by which tobacco smoking contributes to neuroHIV. This review will summarize the differential effects of nicotine vs tobacco smoking on inflammation in addition to the effects of tobacco smoke components on HIV disease progression. We will also discuss biomarkers of inflammation via neuroimaging as well as biomarkers of nicotine dependence (e.g., nicotine metabolite ratio). Tobacco smoking and nicotine may impact ART drug metabolism and conversely, certain ARTs may impact nicotine metabolism. Thus, we will review these bidirectional relationships and how they may contribute to neuroHIV and other adverse outcomes. We will also discuss the effects of tobacco use on the interaction between peripheral organs (lungs, heart, kidney) and subsequent CNS function in the context of HIV. Lastly, given the dramatic rise in the use of electronic nicotine delivery systems, we will discuss the implications of vaping on these processes. Despite the growing recognition of the importance of addressing tobacco use among PLWH, more research is necessary at both the preclinical and clinical level to disentangle the potentially synergistic effects of tobacco use, nicotine, HIV, cognition and immune dysregulation, as well as identify optimal approaches to reduce tobacco use. Graphical Abstract Proposed model of the relationships among HIV, ART, smoking, inflammation, and neurocognition. Solid lines represent relationships supported by evidence. Dashed lines represent relationships for which there is not enough evidence to make a conclusion. (a) HIV infection produces elevated levels of inflammation even among virally suppressed individuals. (b) HIV is associated with deficits in cognition function. (c) Smoking rates are higher among PLWH, compared to the general population. (d) The nicotine metabolite ratio (NMR) is associated with smoking behavior. (e) HIV and tobacco use are both associated with higher rates of psychiatric comorbidities, such as depression, and elevated levels of chronic stress. These factors may represent other mechanisms linking HIV and tobacco use. (f) The relationship between nicotine, tobacco smoking, and inflammation is complex, but it is well-established that smoking induces inflammation; the evidence for nicotine as anti-inflammatory is supported in some studies, but not others. (g) The relationship between tobacco use and neurocognition may differ for the effects of nicotine (acute nicotine use may have beneficial effects) vs. tobacco smoking (chronic use may impair cognition). (h) Elevated levels of inflammation may be associated with deficits in cognition. (i) PLWH may metabolize nicotine faster than those without HIV; the mechanism is not yet known and the finding needs validation in larger samples. We also hypothesize that if HIV-infection increases nicotine metabolism, then we should observe an attenuation effect once ART is initiated. (j) It is possible that the increase in NMR is due to ART effects on CYP2A6. (k) We hypothesize that faster nicotine metabolism may result in higher levels of inflammation since nicotine has anti-inflammatory properties.

Comparative assessment of individual RONS in serum of smokers compared with non-smokers and their correlation with the lipid profile and antioxidant status

Objective

Cigarette smoking generates free radicals, such as reactive oxygen and nitrogen species (RONS) that contribute to many diseases. The aim of this study was to compare the levels of individual RONS in serum from smokers and non-smokers, and to examine their impact on lipid profiles and the endogenous antioxidant status, which is represented by vitamins C and E.

Methods

Ninety-four healthy Egyptian volunteers (48 smokers and 46 non-smokers) were enrolled. Blood samples were collected and analysed for common haematological tests, lipid profiles, and serum antioxidants. Six reactive oxygen species and three reactive nitrogen species were measured.

Results

A significant increase in radical levels was observed, as well as significant increases in haemoglobin (Hb), haematocrit, platelet count, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very low-density lipoprotein cholesterol in smokers compared with non-smokers. In contrast, high-density lipoprotein cholesterol was significantly reduced in smokers compared with non-smokers. A moderate negative correlation was found between serum levels of vitamins C and E and O₂^–•, HO^•, H₂O₂, NO^•, and ONO^•, reflecting a negative impact of elevated RONS levels on the endogenous antioxidant status.

Conclusion

These results may increase our understanding of the pathological role of smoking in several diseases.

The Intersection of Sex Differences, Tobacco Use, and Inflammation: Implications for Psychiatric Disorders

PURPOSE OF REVIEW

Tobacco use, sex differences, and psychiatric disorders are associated with altered immune function. There are also sex differences in tobacco use and psychiatric disorders. This review summarizes findings from the small, but growing literature examining sex differences in the effects of tobacco use on inflammation and the implications for psychiatric disorders.

RECENT FINDINGS

We identified four studies that tested the interaction between sex and tobacco/nicotine on inflammation. Although males and females generally exhibited differential tobacco-induced immune responses, the pattern varied depending on the sample (rodents vs. humans) and the method to evaluate inflammation. Evidence suggests that sex modulates the effects of tobacco smoke on inflammation. Many inflammation markers associated with sex differences and tobacco use are related to psychiatric disorders. We propose a model in which sex, tobacco use, and inflammation interact to increase risk for psychiatric disorders. Future studies are needed to examine the mechanisms that explain this relationship.

Smoking and female sex as key risk factors associated with severe arthralgia in acute and chronic phases of Chikungunya virus infection

Arthralgia is a potentially incapacitating condition and a persistent symptom in chronic or acute episodes of Chikungunya fever caused by infection with the Chikungunya virus (CHIKV). To the best of our knowledge, there are no reports on risk factors associated with the intensity of arthralgias in typical acute episodes of the disease. Although a number of studies have reported on risk factors associated with the development of the chronic stage of the disease, smoking habits have not been analyzed. Smoking is an interesting factor to consider since it is the main environmental risk factor for the development of rheumatoid arthritis (RA), a similar disease to CHIKV in many aspects. In the present study, 140 patients infected with CHIKV were assessed for risk factors associated with severe arthralgia intensity in the acute phase (pain of 9/10 on the visual analog scale of 0-10) and moderate to severe intensity (according to the Routine Assessment of Patient Index Data 3) 3.5 months after infection in patients that experienced the chronic phase of the disease. Women and smokers were 2- to 3-times more likely to experience severe pain in the acute and chronic stages. Likewise, the presence of severe arthralgia during the acute disease phase resulted in a 4-fold increased risk for entering the chronic phase. Smoking was a more important risk factor in males compared with females. Smoking resulted in a 20-fold increased risk for severe arthralgia during the acute phase in men, as well as a 10-fold increased risk for developing chronic disease with moderate-to-severe pain 3.5 months after the acute stage. The presence of rash, headache, muscular weakness or conjunctivitis in the acute phase, the presence of diabetes and age >40 years were considered significant risk factors due to their influence on illness progression. In conclusion, smoking and female sex were the main risk factors associated with development of severe joint pain in the acute and chronic phases of Chikungunya fever. These risk factors are similar to those associated with the development and severity of RA, possibly because the two diseases share pathophysiological mechanisms, including elevated interleukin-6 levels.