C-reactive protein as a predictor of disease in smokers and former smokers: a review

Childhood Racism and Cardiometabolic Risk in Latina Mothers Across the First Postpartum Year

OBJECTIVE

Immigrant Latinas, particularly of Mexican descent, initially achieve healthy perinatal outcomes. Although this advantage wears off across generations in the United States (US), the early life psychosocial mechanisms that may initiate a cascade of biological vulnerabilities remain elusive. The current investigation aimed to understand the extent to which childhood experiences of racism may contribute to elevated levels of C-reactive protein (CRP), an early indicator of cardiometabolic risk, during the first postpartum year.

METHODS

Latinas from the Community and Child Health Network ( N = 457) retrospectively reported experiences of childhood racism and childhood country of residence via structured questionnaires. Interviewers collected CRP bloodspots and height and weight measurements for body mass index at 6 months and 1 year postpartum.

RESULTS

Latinas who grew up in the US experienced a steeper increase of CRP levels across the first postpartum year ( β = 0.131, p = .009) and had higher CRP levels 1 year postpartum than Latinas who grew up in Latin America. Based on Bayesian path analyses, Latinas who grew up in the US reported higher levels of childhood racism than Latinas who immigrated after childhood ( β = 0.27; 95% credible interval = 0.16-0.37). In turn, childhood racism mediated the relationship between country of childhood residence and elevated CRP at 6 months and 1 year postpartum, even after adjusting for sociodemographic and behavioral covariates. After adjusting for body mass index, mediational relationships became nonsignificant.

CONCLUSIONS

This study is an important first step toward understanding how childhood racism may contribute to postmigratory health patterns among Latinas, particularly cardiometabolic risk 1 year after childbirth.

Evaluation on the Sex-Specific Association Between Cigarette Smoke Exposure and Inflammation Markers-C-Reactive Protein and White Blood Cell Count

INTRODUCTION

Cigarette smoke increases peripheral white blood cell (WBC) count. However, the dose-dependent association between smoking and C-reactive protein (CRP), an important inflammatory marker, has been reported as inconsistent.

AIMS AND METHODS

Here, we evaluated the associations between smoking and CRP using both smoking questionnaires and urine cotinine as exposure markers. The Korea National Health and Nutrition Examination Survey data were used for analyzing the associations. Multiple regression analyses were performed to examine the associations between cigarette smoke exposure, as assessed by questionnaires and urine cotinine, and health effects, as measured by CRP and WBC count, controlling for potential confounders. The confounders, including age, sex, body mass index, blood pressure, cholesterol, glucose, alanine aminotransferase, and uric acid, were selected a priori based on the literature.

RESULTS

A total of 11 435 participants were included for analysis. For the exposure-response relationship, the results indicated a significant increase in CRP levels in male smokers compared to male nonsmokers (p = .002), whereas no significant increase was found in female smokers compared to female nonsmokers (p = .680). For the dose-response relationship, a significant positive association was observed between urine cotinine and CRP in male smokers (p = .018), whereas no significant association was found in female smokers (p = .508). WBC count consistently showed significant exposure-response and dose-response relationships in both sexes.

CONCLUSIONS

WBC count was found to be a consistent effect marker of cigarette smoke exposure, while the association between CRP level and smoking was inconsistent and varied by sex. The sex-specific response to cigarette smoke exposure warrants further exploration in future studies.

IMPLICATIONS

Cigarette smoke exposure is known to increase inflammation and has been thought to increase CRP, a significant inflammation marker. However, recent studies have reported conflicting results regarding the dose-dependent association between cigarette smoke exposure and CRP. This study found that the association between smoking and CRP is inconsistent and varies by sex, showing significant exposure response in men but not in women. Furthermore, the study suggests that WBC count is a more consistent marker for cigarette smoke exposure.

Oral supplementation with crocin (a constituent of saffron) in subjects with cigarette smoking: a clinical trial

Smoking is one of the main causes of death in the world. Cigarette use is related with various components of metabolic syndrome (e.g., insulin resistance, raised blood pressure, dyslipidemia, oxidative stress, inflammation state) and psychiatric disorders. This study was conducted to determine the effect of crocin (Cro) supplementation on nicotine dependence, anxiety, depression, and metabolic indices in smokers. A total of 50 smokers were selected and randomly categorized into two groups (crocin and placebo). The intervention group received crocin (30 mg per day; n = 25) and placebo (containing Avicel; n = 25) once a day. The primary (nicotine dependence, depression, and anxiety inventory) and secondary (metabolic indices) outcomes were assessed at the start of the intervention and after the 3 months. Multiple linear regression models were used to assess the treatment effects on the outcomes adjusting for confounding variables. The primary outcome results such as nicotine dependence, depression, and anxiety inventory did not have a significant difference among the intervention groups (P > 0.05). Also in the secondary outcomes, fasting plasma glucose (FPG), insulin, and homeostasis model of assessment-insulin resistance (HOMA-IR) levels did indicate a significant difference by Cro intervention (β - 3.27 mg/dL; 95% CI, - 5.23, - 1.31; P = 0.002; β - 0.76 μIU/mL; 95% CI, - 1.38, - 0.15; P = 0.01; β - 0.18; 95% CI, - 0.29, - 0.07; P = 0.002), respectively. There were also significant reductions in serum levels of high-sensitivity C-reactive protein (hs-CRP) (β - 0.72 mg/L; 95% CI, - 1.37, - 0.07; P = 0.03), compared with the placebo. Cro intake may have favorable effects on the level of FPG, insulin, HOMA-IR, and hs-CRP in smokers. However, due to the small sample size and limited scientific reports on smokers, further studies are necessary. ClinicalTrial.gov Identifier: IRCT20170420033551N11.

Cardiac function, myocardial fat deposition, and lipid profile in young smokers: a cross-sectional study

Background

There is a possibility that cardiac morphometric characteristics are associated with the lipid profile, that is, the composition and concentration of triglycerides, total cholesterol, HDL, LDL, and others lipoproteins in young smokers without comorbidities. Thus, this study aimed to evaluate the association of cardiac morphometric characteristics, myocardial fat deposition, and smoking cessation with the lipid profile of young smokers.

Methods

A clinical and laboratory evaluation of lipids and the smoking status was performed on 57 individuals, including both a smoker group and a control group. Cardiac magnetic resonance imaging (MRI) with proton spectroscopy was performed to identify cardiac changes and triglyceride (TG) deposition in myocardial tissue.

Results

No differences were observed between the groups (control vs. smokers) in relation to the amount of myocardial TG deposition (p = 0.47); however, when TG deposition was correlated with cardiac MRI variables, a positive correlation was identified between smoking history and myocardial TG deposition [hazard ratio (95% CI), 0.07 (0.03-0.12); p = 0.002]. Furthermore, it was observed that the smoking group had lower high-density lipoprotein cholesterol [51 (45.5-59.5) mg/dl vs. 43 (36-49.5) mg/dl, p = 0.003] and higher TG [73 (58-110) mg/dl vs. 122 (73.5-133) mg/dl, p = 0.01] and very-low-density lipoprotein cholesterol [14.6 (11.6-22.2) mg/dl vs. 24.4 (14.7-26.6) mg/dl, p = 0.01] values. In the control and smoking groups, a negative correlation between TGs and the diameter of the aortic root lumen and positive correlation with the thickness of the interventricular septum and end-diastolic volume (EDV) of both the right ventricle (RV) and left ventricle (LV) were noted. Moreover, in the RV, positive correlations with the end-systolic volume (ESV) index (ESVI), stroke volume (SV), ESV, and EDV were observed. Regarding serum free fatty acids, we found a negative correlation between their values and the diameter of the lumen of the ascending aortic vessel. Lipoprotein lipase showed a positive correlation with the SV index of the RV and negative correlation with the diameter of the lumen of the ascending aortic vessel.

Conclusion

Several associations were observed regarding cardiac morphometric characteristics, myocardial fat deposition, and smoking cessation with the lipid profile of young smokers.

A wireless patch for the monitoring of C-reactive protein in sweat

The quantification of protein biomarkers in blood at picomolar-level sensitivity requires labour-intensive incubation and washing steps. Sensing proteins in sweat, which would allow for point-of-care monitoring, is hindered by the typically large interpersonal and intrapersonal variations in its composition. Here we report the design and performance of a wearable and wireless patch for the real-time electrochemical detection of the inflammatory biomarker C-reactive (CRP) protein in sweat. The device integrates iontophoretic sweat extraction, microfluidic channels for sweat sampling and for reagent routing and replacement, and a graphene-based sensor array for quantifying CRP (via an electrode functionalized with anti-CRP capture antibodies-conjugated gold nanoparticles), ionic strength, pH and temperature for the real-time calibration of the CRP sensor. In patients with chronic obstructive pulmonary disease, with active or past infections or who had heart failure, the elevated concentrations of CRP measured via the patch correlated well with the protein's levels in serum. Wearable biosensors for the real-time sensitive analysis of inflammatory proteins in sweat may facilitate the management of chronic diseases.

A prospective hospital-based study on C-reactive protein as a response predictor of antidepressant treatment in drug naïve patients with major depressive disorder

Background

C-reactive protein (CRP) is an acute phase reactant that is implicated in the pathogenesis of major depressive disorder (MDD), due to its role in the execution of various important neurological events, including neurogenesis, mediation of neural plasticity, and synaptic transmission.

Aims

This study was conducted to determine the relationship between the level of CRP to remission rates after antidepressant therapy.

Methods

Fifty patients of first episode MDD with no past history of antidepressant exposure and other medical comorbidity were recruited after obtaining consent for Escitalopram therapy. The CRP levels of the patients were evaluated on the day of recruitment and depressive symptoms were monitored using Montgomery-Asberg Depression Rating Scale at weeks 0, 3, 6, and 12. The patients with low (≤10 mg/l) and high (>10 mg/l) CRP levels were compared for time taken to achieve remission using Kaplan-Meier survival analysis.

Results

The Kaplan-Meier survival analysis showed a significantly higher proportion of patients with low CRP levels attained remission than patients with higher CRP levels (Log-rank = 7.594; dF = 1; P = 0.006). The age, compliance to pharmacotherapy, and disability did not significantly affect the remission rates of the patients.

Conclusion

Our study confirms that higher levels of CRP can lead to poorer remission rates in patients with MDD after antidepressant therapy and can predict treatment resistance.

Coffee or tea: Anti-inflammatory properties in the context of atherosclerotic cardiovascular disease prevention

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of premature death worldwide. Inflammation and its biomarkers, like C-reactive protein (CRP), among the risk factors, such as hypertension, lipid disorders, and diabetes, may be also responsible for the residual cardiovascular disease (CVD) risk. Modern lipid-lowering treatment with statins, ezetimibe, PCSK9 inhibitors, or bempedoic acid does not fully protect against inflammation. The recommendations of the International Lipid Expert Panel (ILEP) indicate selected nutraceuticals with anti-inflammatory properties. Diet may have a significant impact on inflammation. Especially interesting in the context of inflammation is the consumption of coffee and tea. These drinks in many observational studies significantly reduced cardiovascular risk and mortality. The question is whether the anti-inflammatory effects of these drinks contribute significantly to the observed clinical effects. Thus, in this narrative review, we primarily discuss the anti-inflammatory properties of consuming tea and coffee. Based on a comprehensive analysis of the studies and their meta-analyses, inconsistent results were obtained, which makes it impossible to conclusively state how clinically significant the potential anti-inflammatory properties of black and green tea and coffee are. A number of confounding factors can cause the inconsistency of the available results. Consumption of tea and coffee appears to increase adiponectin concentrations, decrease reactive oxygen species, decrease low density lipoprotein (LDL) cholesterol concentrations (effect of green tea, etc.). Despite the still uncertain anti-inflammatory effect of tea and coffee, we recommend their consumption as a part of the healthy diet.

Association between C-Reactive Protein Levels and Functional Disability in the General Older-Population: The Takashima Study

AIMS

High-sensitivity C-reactive protein (hsCRP) associates with atherosclerotic diseases such as stroke. However, previous results on the association between hsCRP levels and functional disability were controversial.

METHODS

We analyzed 2,610 men and women who did not exhibit functional disability or death within the first 3 years of the baseline survey and those aged 65 years or older at the end of follow-up. The levels of hsCRP were assessed using latex agglutination assay at baseline survey from 2006 to 2014. Functional disability was followed up using the long-term care insurance (LTCI) program until November 1, 2019. Functional disability was defined as a new LTCI program certification. Cox proportional hazards model with competing risk analysis for death was used to evaluate the association between hsCRP levels and future functional disability.

RESULTS

During a 9-year follow-up period, we observed 328 cases of functional disability and 67 deaths without prior functional disability incidence. The multivariable-adjusted hazard ratio (HR, 95% confidence interval [CI]) of functional disability in log-transferred hsCRP levels was 1.43 (1.22-1.67) in men and 0.97 (0.81-1.15) in women. When hsCRP level was analyzed as a categorical variable, low hsCRP levels (＜1.0 mg/l) as the reference, the multivariable-adjusted HR (95% CI) of functional disability in high hsCRP levels (≥ 3.0 mg/l) was 2.37 (1.56-3.62). Similar results were observed when stratified by sex, but it was not significant in women.

CONCLUSIONS

This study demonstrates that low-grade systemic inflammation to assess hsCRP might predict the future incidence of functional disability, especially in men.

Association of Duration of Smoking Cessation or Cumulative Smoking Amount with Serum hs-CRP Level in Korean Adults: A Nationwide Population-Based Cross-Sectional Study

This study investigates the association between the duration of smoking cessation or cumulative smoking amount with serum high-sensitivity C-reactive protein (hs-CRP) levels. We assessed the decreasing risk for cardiovascular disease (CVD) and cancer following smoking cessation in Korean adults who were former smokers compared with current smokers. This study used data from the 2016−2018 Korea National Health and Nutrition Examination Survey. A total of 5411 participants were included. The duration of smoking cessation and cumulative smoking amount were classified into cut-offs for 6 and 17 months, and 5 and 20 pack-years, respectively, using tertile values. Elevated serum hs-CRP level was defined as ≥1 mg/L. Multivariate logistic regression analysis was performed. The odds ratio (OR) for elevated serum hs-CRP level was 0.73 times lower in the group whose duration of smoking cessation was 17 months or more than that in the group who were current smokers after adjusting for confounding variables (95% confidence interval (CI): 0.57−0.92; p < 0.01). The OR for elevated serum hs-CRP level was 0.71 and 0.67 times lower in the groups whose cumulative smoking amounts were less than 5 and 5−20 pack-years than that in the group who were current smokers (95% CI: 0.50−0.99 and 0.50−0.92, respectively; both p < 0.05). This study reveals that a duration of smoking cessation of more than 17 months and a cumulative smoking amount of less than 20 pack-years were significantly associated with a decreased risk of elevated serum hs-CRP levels in Korean adults who were former smokers. Therefore, quitting smoking early and a low cumulative smoking amount are a potential preventive strategy for CVD and cancer that can be easily accessible using serum hs-CRP.

Applying Mendelian randomization to appraise causality in relationships between smoking, depression and inflammation

Smoking, inflammation and depression commonly co-occur and may be mechanistically linked. However, key questions remain around the direction of association and the influence of residual confounding. We aimed to characterize the association between lifetime smoking and depression, as well as to assess the role that genetically-predicted C-reactive protein (CRP) level, (an archetypal generalized inflammatory marker) and/or IL-6 activity, as a potential explanation for this association. We performed inverse variance weighted Mendelian randomization (MR) analyses using recently published summary-level GWAS data for lifetime smoking index, CRP levels, and depression. A subset of inflammatory-related genetic variants from the lifetime smoking GWAS were also used to assess the potential inflammatory causal pathways between smoking and depression. The analysis indicated reciprocal relationships of lifetime smoking with depression (ORSmk-Dep = 2.01, 95% CI 1.71-2.37, p < 0.001; ORDep-Smk = 1.09, 95% CI 1.06-1.13, p < 0.001), CRP levels and IL-6 activity (ORSmk-CRP = 1.40, 95% CI 1.21-1.55, p < 0.001; ORCRP-Smk = 1.03, 95% CI 1.02-1.05, p < 0.001, ORIL-6/CRP-Smk = 1.06 (1.03-1.09), p < 0.001). These associations were also supported by the majority of the robust MR methods performed. We did not find evidence for a reciprocal relationship between CRP levels (using > 500 genetic instruments for CRP) and depression (ORCRP-Dep = 1.01, 95% CI 0.99-1.04; ORDep-CRP = 1.03, 95% CI 0.99-1.07). We observed little variation in the IVW estimates between smoking and depression when we limited the genetic variants assessed to those related to measures of generalized inflammation, but we found evidence for an attenuation of the smoking-depression association in multivariable mendelian randomization when adjusting for IL-6 activity, suggesting that the IL-6 pathway may be at least in part responsible for the association of smoking and depression. Our study supports potential bidirectional causal associations between lifetime smoking and depression which may be at least in part explained by the IL-6 signalling pathway. The IL-6 pathway may represent a putative therapeutic target for smoking and to mitigate the effects of smoking on depression.

The role of smoking history in longitudinal changes in C-reactive protein between Black and White older adults in the US

•

This study is the first to examine the effect of race and smoking history on changes in CRP.

•

Overall, there were no significant effects of race or current cigarette smoking on CRP change.

•

In NHWs only, smoking history, education, sex, and BMI were predictive of CRP.

•

In NHBs only, only BMI was predictive of CRP.

•

NHBs may not experience the same reductions in CRP with smoking cessation as NHWs.

Smoking cessation is associated with decreases in C-reactive protein (CRP), a biomarker of systemic inflammation and cancer risk; yet CRP levels remain higher long-term in individuals who quit vs. those who never smoked. While non-Hispanic, Black/African American (NHB) have higher levels of CRP vs. non-Hispanic, White/Caucasian (NHW) adults, the association between CRP and race has not been examined in individuals with smoking history. Utilizing longitudinal data from the Health and Retirement Study (HRS), the current study examined the effects of race and smoking history on CRP in older adults. NHB (n = 242) and NHW (n = 1529) participants completed HRS assessments in 2006, 2010, and 2014. Dried blood spots collected at each wave were assayed for CRP. Linear mixed models were used to examine the effect of race and smoking history on CRP across waves – controlling for sociodemographics, physical activity, body mass index (BMI), and current smoking. Overall, results showed no significant effects of race or current smoking on CRP; rather age, sex, education, BMI, physical activity, smoking history, and time × race predicted CRP (ps<.04). However, while age, sex, education, BMI, physical activity, and smoking history were also predictive of CRP in NHWs (ps<.04) in race-stratified models, only BMI was a significant predictor of CRP in NHBs (p=.012). BMI may be important in explaining inflammation-related disease risk in NHBs with a history of smoking. NHBs may not experience the same reductions in CRP with smoking cessation as NHWs – potentially contributing to tobacco-related health disparities.

Association of Allostatic Load and All Cancer Risk in the SWAN Cohort

Elevated chronic stress is thought to increase cancer risk, though the results so far have been inconsistent. In this study, we assessed the relationship between allostatic load (AL), a biological indicator of chronic stress, and overall cancer risk in 3015 women who participated in the Study of Women’s Health Across the Nation (SWAN). Based on the distribution of AL, the study population was categorized into four groups, from the lowest (1st category) to the highest AL group (4th category). At baseline, African American and Hispanic women were more likely to be in the higher AL categories than White women (p < 0.001). In addition, women who smoked regularly, drank alcohol regularly, had no leisure physical activity, and had restless sleep were also more likely to be in the higher AL categories than their relative counterparts (p < 0.001). We also observed that women in the lower-income category with no health insurance were more likely to be in the higher AL category (p < 0.001). The study then found that women in the 4th category of AL (the highest AL group) had a 1.64-fold increased risk of overall cancer (Hazard ratio (HR): 1.64, 95% confidence interval (CI): 1.04, 2.59). The risk association was further strengthened after adjusting demographics, healthy behaviors, and socioeconomic factors with an HR of 2.08. In further analysis of individual biomarkers of AL score, we found that higher levels of triglyceride and CRP were associated with increased risk of cancer, highlighting the role of metabolic dysfunction and inflammation in the etiology of cancer development. In summary, we report that higher AL is associated with increased cancer risk.

Changes in leukocytes and CRP in different stages of major depression

Background

We recently reported increased levels of neutrophils, monocytes and C-reactive protein (CRP) correlated with symptom severity in acute schizophrenia. Here, we investigated if a similar pattern of innate immune system activation occurs in major depression (MD).

Methods

We assessed differential blood counts, CRP, depression symptoms (HAMD-21) and psychosocial functioning (GAF) in controls (n = 129) and patients with first (FEMD: n = 82) or recurrent (RMD: n = 47) disease episodes of MD at baseline (T0; hospital admission) and after 6-weeks treatment (T6).

Results

Considering smoking, BMI and gender as covariates, neutrophils (FEMD: p = 0.034, RMD: p = 0.034) and CRP (FEMD: p < 0.001, RMD: p = 0.021) were higher, and eosinophils (FEMD: p = 0.005, RMD: p = 0.004) lower in patients versus controls at T0. Baseline lymphocyte counts were elevated in RMD (p = 0.003) but not FEMD. Results were confirmed by analyses of nonsmokers. At follow-up, eosinophils rose significantly in FEMD (p = 0.011) but no significant changes were observed in RMD. Improvement in HAMD-21 correlated with T0–T6 changes of neutrophil counts in FEMD (r = 0.364, p = 0.024). Compared with our previous schizophrenia study, raised baseline neutrophil and reduced eosinophil counts in MD had smaller effect sizes and treatment had a weaker association with T0-T6 changes in neutrophils. In addition, lymphocytes were elevated at T0 in recurrent MD but not in schizophrenia patients.

Conclusions

These findings suggest that innate immunity may be involved in early stages of MD, and adaptive immunity may be involved in chronic disease. Thus, further studies may lead to new disease stage-dependent MD treatment strategies targeting different aspects of immune system activation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02429-7.

C-reactive protein in adult Samoans: Population variation and physiological correlates

OBJECTIVES

C-reactive protein (CRP) has been associated with adiposity and cardiometabolic disease risk in many populations but remains remarkably understudied in Pacific Islander populations. Here, we provide the first examination of correlates of CRP in adult Samoans (n = 108, ages 35-55 years) to test the hypotheses that CRP exhibits sex-dependent associations with measures of BMI, adiposity, and cardiometabolic disease risks.

METHODS

We analyzed associations between measures of adiposity (total fat mass, visceral fat mass, percent total body fat), body mass index (BMI), cardiometabolic risks, behaviors, demographics, and CRP. Unadjusted analyses of CRP were undertaken using Pearson's pairwise, and Spearman's rank correlations; one-way analysis of variance and Kruskal-Wallis tests assessed variables by CRP quartiles. Adjusted analyses of CRP correlates were examined using generalized linear regression.

RESULTS

Serum CRP ranged from 0.08 to 13.3 mg/L (median 1.4 mg/L) and varied significantly by sex t (108) = -2.47, p = .015. CRP was weakly to moderately associated with measures of adiposity and BMI (r and ρ ranged between 0.25 and 0.50, p < .05) and some cardiometabolic markers (including HbA1c, fasting insulin, and insulin resistance). CRP was significantly associated with percent body fat in women and men, adjusting for other variables.

CONCLUSIONS

These data are among the first to demonstrate CRP correlates in a sample of adult Samoans. CRP differed by sex and was associated with BMI, adiposity, and some cardiometabolic risk markers. These data align with findings in other populations.

Different associations of specific non-alcoholic beverages with elevated high-sensitivity C-reactive protein in Korean adults: results from the Korea National Health and Nutrition Examination Survey (2015-2016)

This study examined the associations between specific non-alcoholic beverages and high-sensitivity C-reactive protein (hs-CRP) and their interactions with obesity. The study participants were 4,999 adults aged 19-64 years from the 2015-2016 Korean National Health and Nutrition Examination Survey. The odds ratios (ORs) and 95% confidence intervals (CIs) were obtained using multivariable logistic regression analyses. In women, there was an inverse linear trend between coffee and hs-CRP status (p trend = 0.0137), and a positive linear trend for soda was also found (≥1/week vs never or almost never, OR = 1.79, 95% CI 1.23-2.61, p trend = 0.0127). In the stratification analyses, the associa-tions were only observed in obese women. The associations were inverse for coffee and tea but linearly positive for soda in obese women (p trend<0.05). In men, an inverted J-shaped association between commercial fruit juice/drink and hs-CRP status was found; but after stratification by obesity, the association was linear only in obese men (p trend<0.05, OR = 2.44, 95% CI 1.44-4.16 in ≥1/week vs never or almost never). Coffee and tea in women may be beneficially associated with hs-CRP status, but soda in women and commercial fruit juice/drink in men may be adversely, particularly for obese adults.

Biomarkers of Inflammation and Oxidative Stress among Adult Former Smoker, Current E-Cigarette Users-Results from Wave 1 PATH Study

BACKGROUND

Former smokers who currently use e-cigarettes have lower concentrations of biomarkers of tobacco toxicant exposure than current smokers. It is unclear whether tobacco toxicant exposure reductions may lead to health risk reductions.

METHODS

We compared inflammatory biomarkers (high-sensitivity C-reactive protein, IL6, fibrinogen, soluble intercellular adhesion molecule-1) and an oxidative stress marker (F2-isoprostane) among 3,712 adult participants in Wave 1 (2013-2014) of the Population Assessment of Tobacco and Health Study by tobacco user groups: dual users of cigarettes and e-cigarettes; former smokers who currently use e-cigarettes-only; current cigarette-only smokers; former smokers who do not currently use any tobacco; and never tobacco users. We calculated geometric means (GM) and estimated adjusted GM ratios (GMR).

RESULTS

Dual users experienced greater concentration of F2-isoprostane than current cigarette-only smokers [GMR 1.09 (95% confidence interval, CI, 1.03-1.15)]. Biomarkers were similar between former smokers who currently use e-cigarettes and both former smokers who do not use any tobacco and never tobacco users, but among these groups most biomarkers were lower than those of current cigarette-only smokers. The concentration of F2-isoprostane decreased by time since smoking cessation among both exclusive e-cigarette users (P _trend = 0.03) and former smokers who do not currently use any tobacco (P _trend = 0.0001).

CONCLUSIONS

Dual users have greater concentration of F2-isoprostane than smokers. Exclusive e-cigarette users have biomarker concentrations that are similar to those of former smokers who do not currently use tobacco, and lower than those of exclusive cigarette smokers.

IMPACT

This study contributes to an understanding of the health effects of e-cigarettes.

Depression: Biological markers and treatment

Nowadays depression is considered as a systemic illness with different biological mechanisms involved in its etiology, including inflammatory response, hypothalamic-pituitary-adrenal (HPA) axis dysregulation and neurotransmitter and neurotrophic systems imbalance. Novel "omics" approaches, such as metabolomics and glycomics provide information about altered metabolic pathways and metabolites, as well as disturbances in glycosylation processes affected by or causing the development of depression. The clinical diagnosis of depression continues to be established based on the presence of the specific symptoms, but due to its heterogeneous underlying biological background, that differs according to the disease stage, there is an unmet need for treatment response biomarkers which would facilitate the process of appropriate treatment selection. This paper provides an overview of the role of major stress response system, the HPA axis, and its dysregulation in depression, possible involvement of neurotrophins, especially brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor and insulin-like growth factor-1, in the development of depression. Article discusses how activated inflammation processes and increased cytokine levels, as well as disturbed neurotransmitter systems can contribute to different stages of depression and could specific metabolomic and glycomic species be considered as potential biomarkers of depression. The second part of the paper includes the most recent findings about available medical treatment of depression. The described biological factors impose an optimistic conclusion that they could represent easy obtainable biomarkers potentially predicting more personalized treatment and diagnostic options.

Developing an Internally Validated Veterans Affairs Women Cardiovascular Disease Risk Score Using Veterans Affairs National Electronic Health Records

Background

The current American College of Cardiology/American Heart Association women cardiovascular disease (CVD) risk score suboptimally estimates CVD risk for young and minority women in the military. The current study developed an internally validated CVD risk score for women military service members and veterans using the Veterans Affairs (VA) national electronic health records data.

Methods and Results

The study cohort included 69 574 White, Black, and Hispanic women service members and veterans aged 30 to 79 years in 2007 treated in the VA Health Care System between January 1, 2007 and December 31, 2017 (henceforth, VA women). Stratified by race and ethnicity, the new VA women CVD risk model estimated risk coefficients and 10‐year CVD risk using a time‐variant covariate Cox model. Harrell C‐statistics, calibration plots, and net classification index were used to assess accuracy and prognostic performance of the new VA women CVD risk model. The new internally validated VA women CVD risk score performed better in predicting VA women 10‐year atherosclerosis cardiovascular disease risk than the pooled cohort American College of Cardiology/American Heart Association risk score in both accuracy (White Harrell C‐statistics, 70% versus 61%; Black, 68% versus 63%) and prognostic performance (White net classification index, 0.31; 95% CI, 0.26–0.33; Black net classification index, 0.06; 95% CI, 0.03–0.09).

Conclusions

The proposed VA women CVD risk score improves accuracy of the existing American College of Cardiology/American Heart Association CVD risk assessment tool in predicting long‐term CVD risk for VA women, particularly in young and racial/ethnic minority women.

Allostatic score and its associations with demographics, healthy behaviors, tumor characteristics, and mitochondrial DNA among breast cancer patients

INTRODUCTION

Allostatic load (AL), a composite index, has been used to capture variation in life-course stresses. However, few studies have been carried out among breast cancer patients.

METHODS

In this study, we examined the cross-sectional association of AL with demographics, healthy behaviors, tumor characteristics, and mitochondrial DNA copy number in breast cancer patients. The study used a sub-sample of 934 women with newly diagnosed breast cancer at M.D. Anderson from 2013 to 2018. To construct the AL score, the study used a battery of seventeen factors that represents the activity of five physiological systems: metabolic, cardiovascular, immunological, renal, and liver.

RESULTS

AL was positively associated with the age of disease diagnosis (P = 0.002), and was higher in Black and Hispanic populations than White (P = 0.001 and 0.032, respectively). AL was also found more abundant in those who experienced marital dissolution (P = 0.006), lacked a college education (P = 0.045), currently smoked (P = 0.011), and had low levels of physical activity (P = 0.037) than their counterparts. The study then found that higher AL was associated with increased odds of having poorly differentiated tumors (Odds ratio (OR): 1.40, 95% confidence interval (CI): 1.28, 1.62). An additional significant association was observed between AL with estrogen receptor negative (ER-) (OR = 1.56, 95%CI: 1.02, 2.36) among Black patients. Finally, we observed a significant positive correlation between AL with leukocyte mitochondrial DNA copy number variation (P < 0.001).

CONCLUSIONS

We conclude AL is influenced by selected demographics and healthy behaviors, and further is correlated with tumor characteristics and mitochondrial DNA copy number in breast cancer patients.

The association between residential proximity to brownfield sites and high-traffic areas and measures of immunity

The mechanisms by which neighborhood environmental exposures influence health are poorly understood, although immune system dysregulation represents a potential biological pathway. While many neighborhood exposures have been investigated, there is little research on residential proximity to brownfield waste. Using biomarker data from 262 participants in the Detroit Neighborhood Health Study, we estimated the association between proximity to brownfields and heavy traffic and signal joint T-cell receptor excision circles (sjTRECs, a measure of naive T-cell production), C-reactive protein (CRP, a measure of systemic inflammation), and interleukin-6 (IL-6, a pro-inflammatory cytokine). We assessed residential proximity ≤200 m from brownfields and highways on all three biomarkers using multivariate regression. We demonstrated that living ≤200 m from a brownfield site was associated with a 0.30 (95% CI = 0.59, 0.02, p = 0.04) log_e-unit decrease in sjTRECs per million whole blood cells, as well as non-significantly elevated levels of CRP and IL-6. Heavy traffic was not associated with any biomarker. Persons living in close proximity to brownfield sites had significantly lower naive T-cell production, suggesting accelerated immune aging. Decreased T-cell production associated with brownfield proximity may be caused by toxicant exposure in brownfield sites, or may serve as a marker of other neighborhood stressors.

Impacts of Preoperative Smoking and Smoking Cessation Time on Preoperative Peripheral Blood Inflammatory Indexes and Postoperative Hospitalization Outcome in Male Patients with Lung Cancer and Surgery Treatment

Objective s To investigate the effects of preoperative smoking and smoking cessation time on preoperative peripheral blood inflammatory indexes and postoperative hospitalization outcomes in male patients with lung cancer and surgery therapy.Methods We retrospectively enrolled 637 male patients who underwent curative-intent lung cancer resection between January 2014 and December 2016. Patients were classified as the current smokers, the never smokers, and the ex-smokers based on their smoking history, and the ex-smokers were allocated into five subgroups according to their smoking cessation times (CeT): CeT≤6 weeks, 6weeks<CeT≤1year, 1year<CeT≤5years, 5years<CeT≤10years, CeT>10years. The preoperative peripheral blood white blood cells (WBCs), albumin, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), intraoperative blood loss, 30-day mortality, in-hospital days, hospitalization costs, intensive care unit (ICU), admission days and placement time of closed thoracic drainage tube were compared among different groups.Results There were significant differences in WBC (F=5.275, P<0.001) and albumin (F=2.470, P<0.05) among patients of current smokers, ex-smokers with different smoking cessation time, and never-smokers. The blood WBC count in current smokers (7.7×10 ⁹/L) was significantly higher than that in ex-smokers (7.0×10 ⁹/L)and never-smokers (5.9×10 ⁹/L) (t=-2.145, P<0.05; t=-6.073, P<0.01, respectively). The level of peripheral blood albumin in current smokers (41.1 g/L) was lower than that in ex-smokers (42.1 g/L) and never-smokers (43.2 g/L) (t=2.323, P<0.05; t=3.995, P<0.01, respectively). The level of peripheral blood NLR in current smokers (3.7) was higher than that in ex-smokers (3.1) and never smokers (2.8) (t=-1.836, P<0.05; t=-2.889, P<0.01, respectively). There was no significant difference in WBC, albumin and NLR among five subgroups of different smoking cessation time. No significant difference was observed in intraoperative blood loss, 30-day mortality, hospitalization costs, hospital stay, ICU stay and placement time of closed thoracic drainage tube among groups either. Conclusion Smoking increases the preoperative inflammatory indexes in peripheral blood of lung cancer patients. Smoking cessation has beneficial effect on reducing levels of these inflammatory indexes, which may be not impacted by the time length of smoking cessation. Therefore, lung cancer patients should be encouraged to quit smoking at any time.

Smoking and Physical Activity Explain the Increased Mortality Risk Following Marital Separation and Divorce: Evidence From the English Longitudinal Study of Ageing

BACKGROUND

Marital separation and divorce are associated with an increased risk of early mortality, but the specific biobehavioral pathways that explain this association remain largely unknown.

PURPOSE

This study sought to identify the putative psychological, behavioral, and biomarker variables that can help explain the association of being separated or divorced and increased risk for early mortality.

METHODS

Using data from the English Longitudinal Study of Ageing, a representative community sample of aging adults (N = 5,786), we examined the association of marital status and life satisfaction, health behaviors measured 2 years later, biomarkers measured 4 years later, and mortality outcomes from the subsequent 4 years.

RESULTS

Consistent with prior literature, older adults who were separated/divorced evidenced greater risk of mortality relative to those in intact marriages over the study period, OR = 1.46, 95% CI [1.15, 1.86]. Marital status was associated with lower levels of life satisfaction, β = -0.22 [-0.25, -0.19] and greater likelihood of smoking 2 years later β = 0.17 [0.13, 0.21]. Lower life satisfaction predicted less frequent physical activity 2 years later, β = 0.07 [0.03, 0.10]. Smoking, but not physical activity, predicted poorer lung functioning 2 years later, β = -0.43 [-0.51, -0.35], and poorer lung function predicted increased likelihood of mortality over the following 4 years, β = -0.15 [-0.27, -0.03]. There was a significant total indirect effect of marital status on mortality through these psychological, behavioral, and biomarker variables, β = 0.03 [0.01, 0.05], which fully explained this mortality risk.

CONCLUSIONS

For separated/divorced adults, differences in life satisfaction predict health behaviors associated with poorer long-term lung function, and these intermediate variables help explain the association between marital dissolution and increased risk of earlier mortality.

Exposure to harmful and potentially harmful constituents decreased in smokers switching to Carbon-Heated Tobacco Product

BACKGROUND

"Heat-not-burn" tobacco products are designed to heat processed tobacco instead of combusting it, thus significantly reducing the formation of harmful and potentially harmful constituents (HPHCs) found in cigarette smoke, and ultimately reducing the risk of smoking-related diseases. The Carbon-Heated Tobacco Product (CHTP), a heat-not-burn tobacco product similar in appearance and use ritual to cigarettes, has been developed for smokers who would otherwise continue smoking as an alternative to cigarettes. To evaluate reduced risk of harm potential of CHTP, it is critical to quantify exposure to HPHCs and consequent biological pathway disturbances involved in disease onset in smokers who switch to CHTP.

METHODS

In this 2-arm, parallel-group study, adult healthy smokers, not willing to quit, were randomized to switch to CHTP 1.2 (n = 80) or to continue using cigarettes (n = 40) for 5 days in confinement followed by 85 days in an ambulatory setting. Endpoints included biomarkers of exposure (BoExp) to HPHCs, and to nicotine, urinary excretion of mutagenic constituents (Ames assay), CYP1A2 activity, biomarkers of effect, and safety.

RESULTS

In switchers to CHTP, BoExp were 40%-95% lower compared to smokers after 5 days of product use, with sustained reductions (36%-93%) observed on Day 90. Urine mutagenicity and CYP1A2 activity were also lower in the CHTP group. Exposure to nicotine was higher in the CHTP group at Day 5, but was similar between the two groups at Day 90. Favorable changes in some biomarkers of effect were observed in the CHTP group showing reductions in white blood cell count, soluble intracellular adhesion molecule-1, and 11-dehydro-thromboxane B2, respectively, indicative of reduced inflammation, endothelial dysfunction, and platelet activation.

CONCLUSIONS

Switching from cigarettes to CHTP resulted in significantly reduced exposure to HPHCs and was associated with observed improvements in some biomarkers of effect representative of pathomechanistic pathways underlying the development of smoking-related diseases.

Olfactory dysfunction persists after smoking cessation and signals increased cardiovascular risk

BACKGROUND

Olfaction plays a critical role in health and function in older adults, and impaired sense of smell is a strong predictor of morbidity and mortality. Smoking cigarettes causes olfactory impairment, but the mechanism of damage and ability to recover after cessation are unknown. We investigated the relationship between time since quitting and olfactory dysfunction in order to elucidate the mechanism(s) by which smoking damages the olfactory system and to inform patient counseling.

METHODS

Using longitudinal data from the National Social Life Health and Aging Project (n = 3528 older adults, including 1526 former smokers), we analyzed the association between odor identification performance and time since smoking cessation using multivariate ordinal logistic regression, adjusting for cognition and demographic variables. To test whether vascular disease plays a role, we also assessed the relationship between olfactory decline and incidence of heart attack and heart disease.

RESULTS

Former smokers who quit ≤15 years before testing had significantly impaired olfaction compared to never smokers (p = 0.04), but those who quit >15 years prior did not. Olfactory decline over 5 years showed modest evidence toward predicting increased incidence of heart attack or heart disease (p = 0.08).

CONCLUSION

Olfactory impairment in smokers persists 15 years after quitting, which is consistent with a vascular mechanism of impairment. Indeed, olfactory decline is a predictor of the development of cardiovascular disease. Taken together, these data suggest that olfactory loss may be a useful sign of underlying vascular pathology. Further investigation of olfactory loss as an early biomarker for cardiovascular disease is warranted.

Acute exposure to e-cigarettes causes inflammation and pulmonary endothelial oxidative stress in nonsmoking, healthy young subjects

The effects of e-cigarette (e-cig) aerosol inhalation by nonsmokers have not been examined to date. The present study was designed to evaluate the acute response to aerosol inhalation of non-nicotinized e-cigarettes in terms of oxidative stress and indices of endothelial activation in human pulmonary microvascular endothelial cells (HPMVEC). Ten smoking-naïve healthy subjects (mean age ± SD = 28.7 ± 5.5 yr) were subjected to an e-cig challenge, following which their serum was monitored for markers of inflammation [C-reactive protein (CRP) and soluble intercellular adhesion molecule (sICAM)] and nitric oxide metabolites (NOx). The oxidative stress and inflammation burden of the circulating serum on the vascular network was also assessed by measuring reactive oxygen species (ROS) production and induction of ICAM-1 expression on HPMVEC. Our results show that serum indices of oxidative stress and inflammation increased significantly (P < 0.05 as compared with baseline), reaching a peak at approximately 1-2 h post-e-cig aerosol inhalation and returning to baseline levels at 6 h. The circulatory burden of the serum (ICAM-1 and ROS) increased significantly at 2 h and returned to baseline values 6 h post-e-cig challenge. ROS production by HPMVEC was found to occur via activation of the NADPH oxidase 2 (NOX2) pathways. These findings suggest that even in the absence of nicotine, acute e-cig aerosol inhalation leads to a transient increase in oxidative stress and inflammation. This can adversely affect the vascular endothelial network by promoting oxidative stress and immune cell adhesion. Thus e-cig inhalation has the potential to drive the onset of vascular pathologies.

Extreme-value sampling design is cost-beneficial only with a valid statistical approach for exposure-secondary outcome association analyses

In epidemiology cohort studies, exposure data are collected in sub-studies based on a primary outcome (PO) of interest, as with the extreme-value sampling design (EVSD), to investigate their correlation. Secondary outcomes (SOs) data are also readily available, enabling researchers to assess the correlations between the exposure and the SOs. However, when the EVSD is used, the data for SOs are not representative samples of a general population; thus, many commonly used statistical methods, such as the generalized linear model (GLM), are not valid. A prospective likelihood method has been developed to associate SOs with single-nucleotide polymorphisms under an extreme phenotype sequencing design. In this paper, we describe the application of the prospective likelihood method (ST_EVSD) to exposure-SO association analysis under an EVSD. We undertook extensive simulations to assess the performance of the ST_EVSD method in associating binary and continuous exposures with SOs, comparing it to the simple GLM method that ignores the EVSD. To demonstrate the cost-benefit of the ST_EVSD method, we also mimicked the design of two new retrospective studies, as would be done in actual practice, based on the PO of interest, which was the same as the SO in the EVSD study. We then analyzed these data by using the GLM method and compared its power to that of the ST_EVSD method. We demonstrated the usefulness of the ST_EVSD method by applying it to a benign ethnic neutropenia dataset. Our results indicate that the ST_EVSD method can control type I error well, whereas the GLM method cannot do so owing to its ignorance of EVSD, and that the ST_EVSD method is cost-effective because it has statistical power similar to that of two new retrospective studies that require collecting new exposure data for selected individuals.

Pregnancy-Associated Plasma Protein A (PAPP-A) Concentration in Population of Healthy Young People: Interactions with Tobacco Smoke and Anti-oxidative Status

Pregnancy-associated plasma protein A (PAPP-A) is a high-molecular zinc-binding metalloproteinase that was first detected in the serum of pregnant women. It can also be detected in men and non-pregnant women. Recently, a growing interest in determining the concentration of PAPP-A as a marker of oxidative stress and atherosclerotic processes has been observed. Among the factors that could potentially influence the PAPP-A formation is the exposure to tobacco smoke. Some components of tobacco smoke have an immediate effect on the body and also direct influence on the cardiovascular system. The aim of this study was to evaluate the relation between PAPP-A concentration and either passive or active exposure to tobacco smoke in the population of medicine students (n = 152). The relation between PAPP-A concentration and chosen markers of inflammatory response and anti-oxidative processes was analyzed. The samples of serum, urine, and saliva were collected and main nicotine metabolites in urine samples were determined using ELISA technique. Comparison of the PAPP-A concentrations in the study group revealed that in the group of active smokers, the concentration of the protein was significantly higher than in the group of passive smokers (p = .04) and the group of not-exposed students (p = .006). PAPP-A concentration showed significant positive correlation with the values of FRAP and main nicotine metabolites. The evident influence of both active and passive tobacco smoke exposure on PAPP-A levels in the studied population of young people who in general are not included in the group of high-risk cardiovascular incidents, shows how important early prevention of anti-health behaviors is.

Modeling Gene-Environment Interaction for the Risk of Non-hodgkin Lymphoma

Background: Non-hodgkin lymphoma (NHL) is one of the most common and deadly cancers. There is limited analysis of gene-environment interactions for the risk of NHL. This study intends to explore the interactions between genetic variants and environmental factors, and how they contribute to NHL risk.

Methods: A case-control study was performed in Shanghai, China. The cases were diagnosed between 2003 and 2008 with patients aged 18 years or older. Samples and SNPs which did not satisfy quality control were excluded from the analysis. Weighted and unweighted genetic risk scores (GRS) and environmental risk scores were generated using clustering analysis algorithm. Univariate and multivariable logistic regression analyses were conducted. Moreover, genetics and environment interactions (G × E) were tested on the NHL cases and controls.

Results: After quality control, there are 22 SNPs, 11 environmental variables and 5 demographical variables to be explored. For logistic regression analyses, 5 SNPs (rs1800893, rs4251961, rs1800630, rs13306698, rs1799931) and environmental tobacco smoking showed statistically significant associations with the risk of NHL. Odds ratio (OR) and 95% confidence interval (CI) was 10.82 (4.34–28.88) for rs13306698, 2.84 (1.66–4.95) for rs1800893, and 2.54 (1.43–4.58) for rs4251961. For G × E analysis, the interaction between smoking and dichotomized weighted GRS showed statistically significant association with NHL (OR = 0.23, 95% CI = [0.09, 0.61]).

Conclusions: Several genetic and environmental risk factors and their interactions associated with the risk of NHL have been identified. Replication in other cohorts is needed to validate the results.

Effect of Tobacco Smoking Cessation on C-Reactive Protein Levels in A Cohort of Low-Dose Computed Tomography Screening Participants

Smokers have higher levels of C-Reactive Protein (CRP) compared to never smokers. The role of smoking cessation on CRP is still under debate. Using data from two screening studies conducted in Italy in 2000–2010 on 3050 heavy smokers (including 777 ex-smokers), we estimated multivariate odds ratios (OR) for high CRP (i.e. ≥2 mg/L) according to smoking status. Moreover, in a longitudinal analysis based on 975 current smokers, with a second measurement of CRP after an average study period of 3.4 years, we estimated the changes in CRP according to smoking cessation. Prevalence of high CRP at baseline was 35.8% among ex-smokers and 41.1% among current smokers (significant OR for ex- vs. current smokers: 0.79). After four years since smoking cessation, CRP levels significantly decreased with increasing years of cessation (significant OR for ex-smokers since more than 8 years: 0.55). In the longitudinal analysis, no significant reduction in CRP was found for time since smoking cessation (ORs: 1.21, 1.04, and 0.91 for ex-smokers since 1 year, 2–3 years, and ≥4 years, respectively). In the largest prospective study available so far, we found that smoking cessation has a favourable effect on CRP, but this benefit is not evident in the short-term.

Review of biomarkers to assess the effects of switching from cigarettes to modified risk tobacco products

Context: One approach to reducing the harm caused by cigarette smoking, at both individual and population level, is to develop, assess and commercialize modified risk alternatives that adult smokers can switch to. Studies to demonstrate the exposure and risk reduction potential of such products generally involve the measuring of biomarkers, of both exposure and effect, sampled in various biological matrices.Objective: In this review, we detail the pros and cons for using several biomarkers as indicators of effects of changing from conventional cigarettes to modified risk products.Materials and methods: English language publications between 2008 and 2017 were retrieved from PubMed using the same search criteria for each of the 25 assessed biomarkers. Nine exclusion criteria were applied to exclude non-relevant publications.Results: A total of 8876 articles were retrieved (of which 7476 were excluded according to the exclusion criteria). The literature indicates that not all assessed biomarkers return to baseline levels following smoking cessation during the study periods but that nine had potential for use in medium to long-term studies.Discussion and conclusion: In clinical studies, it is important to choose biomarkers that show the biological effect of cessation within the duration of the study.

Time From Smoking Cessation and Inflammatory Markers: New Evidence From a Cross-Sectional Analysis of ELSA-Brasil

Introduction

The time for inflammatory markers of former smokers to revert to never smoker levels is still controversial, ranging from 5 to 20 years. We aimed to determine the time from smoking cessation for white blood cell (WBC) count and serum C-reactive protein (CRP) levels to return to those of never-smokers, after adjusting for confounding factors and for secondhand smoke (SHS) exposure among participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

Methods

Cross-sectional analysis of baseline participants of ELSA-Brasil. We used linear regression analysis and generalized linear models with gamma distribution and logarithmic link function to estimate the association of WBC count and CRP levels with time from smoking cessation. The following confounding factors were considered: sex, age, education, SHS, alcohol consumption, leisure-time physical activity, BMI, total cholesterol/HDL ratio, hypertension, diabetes, cardiovascular disease, and chronic obstructive pulmonary disease (COPD). Results: After all adjustments, time from smoking cessation <10 years remained associated with higher WBC count (eg, time from smoking cessation ≥ 5 and <10 years: β: 167.92; 95%CI: 23.52 312.31), while only time from smoking cessation <1 year remained associated with higher arithmetic mean of CRP (AMR: 1.26, 95%CI: 1.03‒1.54).

Conclusions

Levels of inflammatory markers were similar to those of never-smokers 1 year after smoking cessation for CRP and 10 years after for WBC.

Implications

The results may add to the arsenal health professionals have to encourage their patients to quit smoking, as some harms from smoking appear to revert to never-smokers' level sooner than previously reported. Longitudinal studies should confirm our findings.

Tumor necrosis factor receptor 2 as a possible marker of COPD in smokers and ex-smokers

Introduction

Oxidative stress and systemic inflammation are higher in smokers and patients with COPD; however, markers that may help differentiate between smokers and patients with COPD have not yet been identified. We hypothesized that tumor necrosis factor-alpha receptor (TNFR) and soluble form of the receptor for advanced glycation end products (sRAGE) can be indicators of COPD in asymptomatic patients.

Patients and methods

We evaluated 32 smokers (smoking history >10 pack-years), 32 patients with mild/moderate COPD (smokers and ex-smokers), and 32 never smokers. Concentrations of C-reactive protein (CRP), interleukin (IL)-6, TNFR1 and TNFR2, advanced glycation end products (AGEs), and the sRAGE were measured in serum.

Results

There were higher CRP and AGEs concentrations in smokers and in patients with COPD (P<0.001 and P=0.01, respectively) compared to controls, without statistical difference between smokers and patients with COPD. Concentrations of sRAGE, IL-6, and TNFR1 did not differ between study groups. TNFR2 was significantly higher in patients with COPD than in smokers (P=0.004) and controls (P=0.004), and the presence of COPD (P=0.02) and CRP (P=0.001) showed a positive association with TNFR2. Positive associations for smoking (P=0.04), CRP (P=0.03), and IL-6 (P=0.03) with AGEs were also found. The interaction variable (smoking × COPD) showed a positive association with IL-6.

Conclusion

Our data suggest that TNFR2 may be a possible marker of COPD in asymptomatic smokers and ex-smokers. Although smokers and patients with early COPD presented other increased systemic inflammation markers (eg, CRP) and oxidative stress (measured by AGEs), they did not differentiate smokers from COPD.

Association between C-reactive protein (CRP) with depression symptom severity and specific depressive symptoms in major depression

INTRODUCTION

Population-based studies have associated inflammation, particularly higher C-reactive protein (CRP), with depressive severity, but clinical trials in major depressive disorder were rather non-specific without examining the role of gender. We aimed to investigate the association between CRP and overall depression severity including specific depressive symptoms and to examine potential gender differences.

METHODS

We included 231 individuals with major depressive disorder from the Genome-Based Therapeutics Drugs for Depression (GENDEP) study. At baseline, we assessed high-sensitivity CRP levels and psychopathology with the Montgomery Aasberg Depression Rating Scale (MADRS). We performed linear regression analyses to investigate the association between baseline CRP levels with overall MADRS severity and specific symptoms at baseline and adjusted for age, gender, anti-inflammatory and psychotropic drug treatment, body mass index, smoking, inflammatory diseases, and recruitment center.

RESULTS

Higher CRP levels were significantly associated with greater overall MADRS symptom severity (p=0.02), which was significant among women (p=0.02) but not among men (p=0.68). Among women, higher CRP was associated with increased severity on observed mood, cognitive symptoms, interest-activity, and suicidality, but we found no significant associations among men. Interaction analyses showed no significant gender differences on the overall MADRS score or specific symptoms.

DISCUSSION

Our results support the sickness syndrome theory suggesting that chronic low-grade inflammation may be associated with a subtype of depression. The potential gender differences in psychopathology may be explained by biological and/or psychosocial factors, e.g. differential modulation of immune responses by sex hormones. Clinical studies should investigate symptom-specific and/or gender-specific treatment guided by peripheral inflammatory markers.

High-Sensitive C-Reactive Protein Levels in a Group of Syrian University Male Students and Its Associations with Smoking, Physical Activity, Anthropometric Measurements, and Some Hematologic Inflammation Biomarkers

In Syria, health risk data on young males are limited. Hence, the aim of the present study was to evaluate cardiovascular disease (CVD) risk factors along with C-reactive protein levels measured by high-sensitive method (hsCRP) in a group of healthy males of university students (n = 101, 18–25 years old). Participants' anthropometric characteristics; alcohol drinking, smoking, and physical activity habits; parents medical history; and some inflammatory biomarkers were inspected for their associations with hsCRP. Results. Regarding hsCRP level, 19 participants were at average (1–3 mg/L) and 13 were at high (>3 mg/L) risk of CVD. Nonparametric statistical tests (p value < 0.05) revealed that hsCRP level was higher in participants who had high body mass index (BMI), had high BMI with high waist-to-hip ratio (WHR), or did not practice sport frequently. Unexpectedly, it did not vary between smokers and nonsmokers. In general, it correlated positively with anthropometric and erythrocyte sedimentation rate (ESR) measurements. Nevertheless, it negatively correlated with sports practicing in overall and nonsmoker groups and in participants whose parents were without medical history. Finally, when participants with high BMI were smokers, did not practice sport frequently, or had a parent with medical history, their hsCRP levels were higher than others who had the same circumstances but with low BMI.

The Inflammatory Potential of the Diet Is Associated with Depressive Symptoms in Different Subgroups of the General Population

Background: Low-grade chronic inflammation, which can be modulated by diet, has been suggested as an important risk factor for depression, but few studies have investigated the association between the inflammatory potential of the diet and depression.Objective: We investigated the prospective association between the inflammatory potential of the diet, measured by the Dietary Inflammatory Index (DII), and incident depressive symptoms and tested the potential modulating effect of sex, age, physical activity, and smoking status.Methods: This study included 3523 participants (aged 35-60 y) from the SU.VI.MAX (Supplémentation en Vitamines et Minéraux Antioxydants) cohort, who were initially free of depressive symptoms. Baseline DII (1994-1996) was computed by using repeated 24-h dietary records. Incident depressive symptoms were defined by a Center for Epidemiologic Studies-Depression Scale score ≥17 for men and ≥23 for women in 2007-2009. We used multivariable logistic regression models to estimate ORs and 95% CIs, and modeled the DII as a continuous variable and as sex-specific quartiles.Results: A total of 172 cases of incident depressive symptoms were identified over a mean follow-up of 12.6 y. The DII was not associated with incident depressive symptoms in the full sample. In sex-specific models, men with a higher DII had a higher risk of incident depressive symptoms (quartile 4 compared with quartile 1-OR: 2.32; 95% CI: 1.01, 5.35), but the association was only marginally significant (P-trend = 0.06). When analyses were performed across smoking status, current and former smokers with a higher DII had a higher risk of incident depressive symptoms (quartile 4 compared with quartile 1-OR: 2.21; 95% CI: 1.08, 4.52). A positive association was also observed among less physically active participants (quartile 4 compared with quartile 1-OR: 2.07; 95% CI: 1.05, 4.07).Conclusion: The promotion of a healthy diet with anti-inflammatory properties may help to prevent depressive symptoms, particularly among men, smokers, or physically inactive individuals. This trial was registered at clinicaltrials.gov as NCT0027242.

Markers of systemic inflammation and colorectal adenoma risk: Meta-analysis of observational studies

AIM

To perform a meta-analysis of observational studies on inflammatory markers levels and occurrence of colorectal adenoma.

METHODS

PubMed and EMBASE databases were searched until March 2016 for the articles reporting on the circulating levels of inflammatory markers, including: C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) and risk of colorectal adenoma. Random-effects models were used to calculate summary odds ratios (ORs) with 95%CIs for the highest vs lowest category of exposure. Heterogeneity was assessed by using the Q test and I² statistic. Subgroup analyses were also performed to test for potential source of heterogeneity.

RESULTS

A total of 14 case-control studies were included. Ten studies on CRP including a total of 3350 cases and 4168 controls showed non-significant summary (OR = 1.23, 95%CI: 0.98-1.54; I² = 54%, P_{heterogeneity} = 0.01) in the general analysis, but significant increased odds when considering only advanced adenoma (OR = 1.59, 95%CI: 1.09-2.32; I² = 44%, P_{heterogeneity} = 0.15). Subgroup and stratified analyses revealed a potential influence of smoking status and aspirin use on the association between CRP levels and colorectal adenoma. Five studies examined the association between circulating levels of TNF-α and colorectal adenoma risk, including a total of 1,568 cases and 2,832 controls. The summary OR for the highest vs the lowest category of exposure was 1.00 (95%CI: 0.77-1.29). The relationship between circulating IL-6 levels and colorectal adenoma risk was investigated in 7 studies including a total of 1936 cases and 3611 controls. The summary OR for the highest vs the lowest category of exposure was 1.19 (95%CI: 0.92-1.55).

CONCLUSION

Summary of current evidence suggests a positive association of CRP levels and advanced colorectal adenoma risk. The role of potential confounding factors should be further evaluated.

The prevalence of metabolic syndrome increases with serum high sensitivity C-reactive protein concentration in individuals without a history of cardiovascular disease: a report from a large Persian cohort

Background

Metabolic syndrome is defined by a clustering of cardiovascular risk factors and is associated with a heightened inflammatory state. A raised serum high-sensitivity C-reactive protein, a marker of inflammation, is also known to associate with cardiovascular risk. We have investigated the relationship between the presence of metabolic syndrome and serum high-sensitivity C-reactive protein concentration in a large representative Persian population cohort without a history of cardiovascular disease.

Methods

The MASHAD study population cohort comprised 9778 subjects, who were recruited from the city of Mashhad, Iran, between 2007 and 2008. Several cardiovascular risk factors were measured in this population without cardiovascular disease. Individuals were categorized into quartiles of serum high-sensitivity C-reactive protein concentration: first quartile – 0.72 (0.59–0.85) (median [range]) mg/L, second quartile – 1.30 (1.14–1.4) mg/L, third quartile – 2.29 (1.92–2.81) mg/L and fourth quartile – 6.63 (4.61–11.95) mg/L, respectively. The prevalence of metabolic syndrome in each quartile was determined using either International Diabetes Federation or Adult Treatment Panel III criteria.

Results

The prevalence of metabolic syndrome was highest in the fourth quartile for serum high-sensitivity C-reactive protein (1220 subjects [50.0%]), and significantly higher than that in the first quartile (reference group) (634 subjects [25.9%]) ( P < 0.001). A positive smoking habit (OR, 1.47 [1.26–1.70], P < 0.001) and the presence of either metabolic syndrome-International Diabetes Federation (OR, 1.35 [1.18–1.55], P < 0.001) or metabolic syndrome-ATPIII (OR, 1.40 [1.18–1.50], P < 0.001) were strong predictors of a fourth quartile for serum high-sensitivity C-reactive protein concentration.

Conclusions

There was a significant association between high concentrations of serum high-sensitivity C-reactive protein and the presence of metabolic syndrome among individuals without a history of cardiovascular disease in our Persian cohort.

Blood Pressure Control in Smokers with Arterial Hypertension Who Switched to Electronic Cigarettes

Electronic cigarettes (ECs) are battery-operated devices designed to vaporise nicotine, which may help smokers with quitting or reducing their tobacco consumption. No data is available regarding the health effects of ECs use among smokers with arterial hypertension and whether regular use results in blood pressure (BP) changes. We investigated long-term changes in resting BP and level of BP control in hypertensive smokers who quit or reduced substantially their tobacco consumption by switching to ECs. A medical records review of patients with hypertension was conducted to identify patients reporting regular daily use of ECs on at least two consecutive follow-up visits. Regularly smoking hypertensive patients were included as a reference group. A marked reduction in cigarette consumption was observed in ECs users (n = 43) though consumption remained unchanged in the control group (n = 46). Compared to baseline, at 12 months (follow-up visit 2) decline in cigarette consumption was associated with significant reductions in median (25th-, 75th-centile) systolic BP (140 (134.5, 144) to 130 (123.5, 138.5) mmHg; p < 0.001) and diastolic BP (86 (78, 90) to 80 (74.5, 90) mmHg; p = 0.006). No significant changes were observed in the control group. As expected, decline in cigarette consumption in the ECs users was also associated with improved BP control. The study concludes that regular ECs use may aid smokers with arterial hypertension reduce or abstain from cigarette smoking, with only trivial post-cessation weight gain. This resulted in improvements in systolic and diastolic BP as well as better BP control.

S100A12 is up-regulated in pulmonary tuberculosis and predicts the extent of alveolar infiltration on chest radiography: an observational study

Pulmonary tuberculosis (PTB) results in lung functional impairment and there are no surrogate markers to monitor the extent of lung involvement. We investigated the clinical significance of S100A12 and soluble receptor for advanced glycation end-products (sRAGE) for predicting the extent of lung involvement. We performed an observational study in India with 119 newly diagnosed, treatment naïve, sputum smear positive, HIV-negative PTB patients and 163 healthy controls. All patients were followed-up for six months. Sociodemographic variables and the serum levels of S100A12, sRAGE, esRAGE, HMGB-1, TNF-α, IFN-γ and CRP were measured. Lung involvement in PTB patients was assessed by chest radiography. Compared with healthy controls, PTB patients had increased serum concentrations of S100A12 while sRAGE was decreased. S100A12 was an independent predictor of disease occurrence (OR 1.873, 95%CI 1.212-2.891, p = 0.004). Under DOTS therapy, S100A12 decreased significantly after 4 months whereas CRP significantly decreased after 2 months (p < 0.0001). Importantly, although CRP was also an independent predictor of disease occurrence, only S100A12 was a significant predictor of lung alveolar infiltration (OR 2.60, 95%CI 1.35-5.00, p = 0.004). These results suggest that S100A12 has the potential to assess the extent of alveolar infiltration in PTB.

Health Behavior Combinations and Their Association With Inflammation

Purpose:

Studies have examined the independent and additive effects of health behaviors (e.g., physical activity, diet, sleep, and smoking) on systemic inflammation, but we know little about whether different pairs of these behaviors differentially influence inflammation, which was the purpose of this study.

Design:

Cross-sectional.

Setting:

The National Health and Nutrition Examination Survey (NHANES) 2005–2006.

Subjects:

A total of 2051 adults (≥20 years).

Measures:

A questionnaire/interview was used to assess sleep and dietary behavior; physical activity was assessed via accelerometry; smoking was assessed via cotinine levels; and a blood sample was taken to assess systemic inflammation (C-reactive protein; [CRP]).

Analysis:

Multivariable linear regression analysis.

Results:

Six health behavior pairs were evaluated: (1) active and healthy diet, (2) active and adequate sleep, (3) active and nonsmoker, (4) healthy diet and adequate sleep, (5) healthy diet and nonsmoker, and (6) adequate sleep and nonsmoker. After adjusting for age, gender, race-ethnicity, poverty level, and chronic disease, only active and nonsmoker (β = −.15) and healthy diet and adequate sleep (β = −.16) were associated with CRP.

Conclusion:

Regular physical activity and smoking avoidance and healthy eating and adequate sleep were the two health behavior pairs associated with less inflammation. This suggests that certain health behaviors may act synergistically on reducing systemic inflammation, whereas other health behavior combinations may not. Such knowledge may help to develop and implement tailored health behavior interventions.

Cigarette smoke compounds induce cellular redox imbalance, activate NF-κB, and increase TNF-α/CRP secretion: a possible pathway in the pathogenesis of COPD

Cigarette smoke has always been considered as a risk factor for chronic obstructive pulmonary diseases (COPD). In this study, we have examined the effect of ten individual cigarette smoke compounds (nicotine, benzo[a]pyrene, naphthalene, formaldehyde, ammonia, acrylic acid, toluene, benzene, m-xylene, and hexamine) on glutathione S transferase (GST) activity, an important Phase II metabolic enzyme and their possible role in inflammatory pathophysiology leading to COPD. Lower Glutathione (GSH) levels and GST activity and higher CRP, TNF-α, and IL-6 levels were observed in COPD patients compared to age and gender-matched controls. Using human recombinant GST and plasma as well as erythrocytes collected from normal subjects this study demonstrates that out of the ten compounds, nicotine (5 mg mL^-1), benzo[a]pyrene (10 ng mL^-1), naphthalene (250 μg mL^-1), and formaldehyde (5 pg mL^-1) caused a significant decrease in recombinant, plasma, and erythrocyte GST activity. Further cell culture studies show that exposure to nicotine, benzo[a]pyrene, naphthalene, and formaldehyde caused a significant decrease in GSH levels and GST activity and its protein expression and an increase in intracellular ROS production in THP-1 monocytes. Interestingly, treatment with benzo[a]pyrene and naphthalene significantly up regulated the phosphorylation of the p65 subunit of NF-κB and increased the secretion of TNF-α and CRP compared to control. This study suggests the potential role of benzo[a]pyrene and naphthalene in the activation of the inflammatory signaling pathway leading to cigarette smoke-induced COPD.

Association between C-reactive protein and physical performance in older populations: results from the International Mobility in Aging Study (IMIAS)

BACKGROUND AND OBJECTIVE

C-reactive protein (CRP) is a widely used cardiovascular risk marker, but questions remain about its role in the disability process in old age. This study examines the associations between CRP levels and physical performance in old age in different societies.

METHODS

data were collected during the baseline survey of IMIAS in 2012 in Kingston (Canada), Saint-Hyacinthe (Canada), Manizales (Colombia) and Natal (Brazil). Approximately 200 men and 200 women aged 65-74 were recruited at each site. CRP was assessed using a high sensitivity assay and categorised as low (<1 mg/l), moderate (1-3 mg/l), high (3-10 mg/l) and very high (≥10 mg/l). Participants were interviewed at home; blood pressure, weight and height were measured. Physical function was assessed with the Short Physical Performance Battery (SPPB) and hand grip strength. Data were analysed using descriptive statistics, bivariate analysis (χ²) and linear or logistic regression.

RESULTS

CRP was significantly associated with low hand grip strength and poor physical performance in bivariate analyses. Hand grip strength association with CRP disappeared after adjustment by socioeconomic factors and health behaviours. The odds of poor physical function was OR = 2.67 [95% CI 1.43-4.99] comparing the highest and lowest CRP categories after adjustment by relevant covariates. The three SPPB components were assessed separately. Graded associations between low CRP and faster gait speed and shorter time to rise from a chair were observed in adjusted models. Association between impaired balance and CRP was attenuated after adjustment by relevant covariates, OR = 1.15 [0.65-2.04].

CONCLUSIONS

CRP could be a possible pathway from inflammation to physical decline in older populations.

Switching from usual brand cigarettes to a tobacco-heating cigarette or snus: Part 3. Biomarkers of biological effect

A randomized, multi-center study of adult cigarette smokers switched to tobacco-heating cigarettes, snus or ultra-low machine yield tobacco-burning cigarettes (50/group) for 24 weeks was conducted. Evaluation of biomarkers of biological effect (e.g. inflammation, lipids, hypercoaguable state) indicated that the majority of consistent and statistically significant improvements over time within each group were observed in markers of inflammation. Consistent and statistically significant differences in pairwise comparisons between product groups were not observed. These findings are relevant to the understanding of biomarkers of biological effect related to cigarette smoking as well as the risk continuum across various tobacco products (ClinicalTrials.gov Identifier: NCT02061917).

C-reactive protein levels in stable COPD patients: a case-control study

Background

Previous studies have documented that C-reactive protein (CRP) levels are increased in stable COPD patients. However, most studies have also shown that higher CRP levels are observed in patients with comorbidities like diabetes mellitus and cardiovascular disease. We aimed to investigate if CRP levels are increased in stable COPD patients, and if there is an association between CRP levels and pulmonary function tests and clinical characteristics.

Methods

We conducted a case-control study in a tertiary care, university-affiliated hospital. COPD patients and controls were matched for sex and age in a 2:1 matching ratio. We included only those patients who had quit smoking. CRP levels were determined and pulmonary function tests were performed in both the groups.

Results

A total of 60 COPD patients and 30 controls were included in the analysis. The study subjects had a mean age of 64.8±8.5 years in COPD group and 64.3±9.2 years in control group (P=0.214). The median of CRP levels was 3.17 mg/L (interquartile range [IQR]: 1.73–5.99 mg/L) in COPD group and 2.13 mg/L (IQR: 1.18–7.69 mg/L) in control group (P=0.370). There were 34 (56.7%) patients in COPD group and 14 (46.7%) patients in control group with CRP levels greater than 3 mg/dL (P=0.382). Using bivariate correlations, we found significant positive correlations in COPD patients between body mass index (BMI) and CRP (r=0.3, P=0.045), and between CRP and forced vital capacity (FVC, % of predicted) (r=−0.3; P=0.023). In a multivariate model, female sex and FVC (% of predicted) were associated with a CRP value greater than 3 mg/dL in the COPD group.

Conclusion

The levels of CRP in the stable COPD patients were not significantly different when compared to those in the control subjects. Female sex and FVC (% predicted) were associated with CRP levels greater than 3 mg/dL in the COPD group.

Association between smoking habits and severity of coronary stenosis as assessed by coronary computed tomography angiography

Smoking promotes arteriosclerosis and is one of the most important coronary risk factors. However, few studies have investigated the association between smoking habits and the severity of coronary stenosis as assessed by coronary computed tomography angiography (CTA). We enrolled 416 patients [165/251 = smoker (past and current)/non-smoker)]. They had all undergone CTA and either were clinically suspected of having coronary artery disease (CAD) or had at least one cardiovascular risk factor. We divided the patients into smoking and non-smoking groups, and evaluated the presence of CAD, the number of significantly stenosed coronary vessels (VD), and the Gensini score as assessed by CTA in the two groups. The incidence of CAD, VD, the Gensini score, and coronary calcification score in the smoking group were all significantly greater than those in the non-smoking group (CAD, p = 0.009; VD, p = 0.003; Gensini score, p = 0.007; coronary calcification score, p = 0.01). Pack-year was significantly associated with VD and the Gensini score, and was strongly associated with multi-vessel disease (2- and 3-VD) (p < 0.05), whereas the duration of cessation in past smokers was not associated with VD or the Gensini score. Pack-year, but not the duration of cessation, may be the most important factor that was associated with the severity of coronary stenosis in terms of VD and the Gensini score.