Distribution and determinants of serum high-sensitive C-reactive protein in a population of young adults: The Cardiovascular Risk in Young Finns Study

Association between C10X polymorphism in the CARD8 gene and inflammatory markers in young healthy individuals in the LBA study

BACKGROUND

The Caspase activation and recruitment domain 8 (CARD8) protein is a component of innate immunity as a negative regulator of NF- ĸB, and has been associated with regulation of proteins involved in inflammation. Expression of CARD8 mRNA and protein has been identified in human atherosclerotic lesions, and the truncated T30A variant (rs2043211) of CARD8 has been associated with lower C-reactive (CRP) and MCP-1 levels in myocardial infarction patients. The present study examines the role of a genetic variation in the CARD8 gene in relation to a selection of markers of inflammation.

METHODS

In a cross-sectional study of young healthy individuals (18.0-25.9 yrs, n = 744) the association between the rs2043211 variant in the CARD8 gene and protein markers of inflammation was assessed. Genotyping of the CARD8 C10X (rs2043211) polymorphism was performed with TaqMan real time PCR on DNA from blood samples. Protein levels were studied via Olink inflammation panel ( https://olink.com/ ). Using linear models, we analyzed men and two groups of women with and without estrogen containing contraceptives separately, due to previous findings indicating differences between estrogen users and non-estrogen using women. Genotypes were analyzed by additive, recessive and dominant models.

RESULTS

The minor (A) allele of the rs2043211 polymorphism in the CARD8 gene was associated with lower levels of CCL20 and IL-6 in men (CCL20, Additive model: p = 0.023; Dominant model: p = 0.016. IL-6, Additive model: p = 0.042; Dominant model: p = 0.039). The associations remained significant also after adjustment for age and potential intermediate variables.

CONCLUSIONS

Our data indicate that CARD8 may be involved in the regulation of CCL20 and IL-6 in men. No such association was observed in women. These findings strengthen and support previous in vitro data on IL-6 and CCL20 and highlight the importance of CARD8 as a factor in the regulation of inflammatory proteins. The reason to the difference between sexes is however not clear, and the influence of estrogen as a possible factor important for the inflammatory response needs to be further explored.

Salivary biomarkers: novel noninvasive tools to diagnose chronic inflammation

Several chronic disorders including type 2 diabetes (T2D), obesity, heart disease and cancer are preceded by a state of chronic low-grade inflammation. Biomarkers for the early assessment of chronic disorders encompass acute phase proteins (APP), cytokines and chemokines, pro-inflammatory enzymes, lipids and oxidative stress mediators. These substances enter saliva through the blood flow and, in some cases, there is a close relation between their salivary and serum concentration. Saliva can be easily collected and stored with non-invasive and cost-saving procedures, and it is emerging the concept to use it for the detection of inflammatory biomarkers. To this purpose, the present review aims to discuss the advantages and challenges of using standard and cutting-edge techniques to discover salivary biomarkers which may be used in diagnosis/therapy of several chronic diseases with inflammatory consequences with the pursuit to possibly replace conventional paths with detectable soluble mediators in saliva. Specifically, the review describes the procedures used for saliva collection, the standard approaches for the measurement of salivary biomarkers and the novel methodological strategies such as biosensors to improve the quality of care for chronically affected patients.

Psychiatric symptoms are not associated with circulating CRP concentrations after controlling for medical, social, and demographic factors

Elevated serum concentrations (>3 mg/L) of the acute-phase protein, C-reactive protein (CRP), is used as a clinical marker of inflammation and is reported to be a strong risk factor for cardiovascular disease. In psychiatric populations, CRP concentration is reported to be higher in depressed versus healthy individuals. Positive associations between CRP and depression have been established in both clinical and community samples, but effect sizes are attenuated after controlling for confounding variables. Similarly, emerging research has begun to draw a link between inflammation, symptoms of anxiety, and substance abuse. Given the high level of comorbid anxiety and substance use disorders in many depressed populations, this study examined whether depression (Patient Health Questionnaire 9 [PHQ-9]) and substance use-related (Drug Abuse Screening Test [DAST]) symptoms were associated with CRP concentrations in the blood after adjusting for relevant medical, social, and demographic covariates in a large sample undergoing screening for several transdiagnostic psychiatric research studies. A total of 1,724 participants were analyzed for association of CRP with variables using multivariate linear regression. An unadjusted model with no covariates showed that PHQ-9 was significantly associated with CRP in All (β = 0.125), Female (β = 0.091), and Male (β = 0.154) participants, but DAST was significantly associated with CRP in males only (β = 0.120). For the adjusted model, in both males and females, mood-stabilizer treatment (β = 0.630), opioid medication (β = 0.360), body mass index (β = 0.244), percent body fat (β = 0.289), nicotine use (β = 0.063), and self-reported sleep disturbance (β = 0.061) were significantly associated with increased CRP concentrations. In females, oral contraceptive use (β = 0.576), and waist-to-hip ratio (β = 0.086), and in males, non-steroidal anti-inflammatory drug use (β = 0.367) were also associated with increased CRP concentrations. There was no significant association between CRP and individual depressive, anxiety, or substance use-related symptoms when covariates were included in the regression models. These results suggest that associations between circulating CRP and the severity of psychiatric symptoms are dependent on the type of covariates controlled for in statistical analyses.

CRP levels are significantly associated with CRP genotype and estrogen use in The Lifestyle, Biomarker and Atherosclerosis (LBA) study

Background

The C-reactive protein (CRP) is an important biomarker for atherosclerosis and single nucleotide polymorphisms (SNPs) in the CRP locus have been associated with altered CRP levels and associated with risk for cardiovascular disease. However, the association between genetic variations in the CRP gene, estrogen use and CRP levels or early signs of atherosclerosis in young healthy individuals is not fully characterized. We aimed to evaluate the influence of five genetic variants on both plasma CRP levels and carotid intima-media thickness (cIMT) values, including aspects on estrogen containing contraceptive use in females.

Methods

Genotyping was performed with TaqMan real time PCR and compared with high sensitivity CRP serum levels in 780 Swedish young, self-reported healthy individuals. Haplotypes of the SNPs were estimated with the PHASE v 2.1. The cIMT was measured by 12 MHz ultrasound. The contraceptive use was self-reported.

Results

Strong associations between CRP and genotype were observed for rs3091244, rs1800947, rs1130864, and rs1205 in women (all p < 0.001). In men, only rs1800947 was associated with CRP (p = 0.029). The independent effect of genotypes on CRP remained significant also after adjustment for established risk factors. Female carriers of the H1/ATGTG haplotype had higher CRP than non-carriers. This was specifically pronounced in the estrogen-using group (p < 0.001), and they had also higher cIMT (p = 0.002) than non-carriers but with a small cIMT difference between the haplotype groups (0.02 mm). In parallel, a significant correlation between CRP and cIMT in the estrogen using group was observed (r = 0.194; p = 0.026).

Conclusions

Estrogen use, genotypes and haplotypes in the CRP locus are significantly associated with CRP levels. Based on an observed interaction effect between sex/estrogen use and the H1/ATGTG haplotype on CRP, and a marginally thicker cIMT in the estrogen using group, our data suggest that both genotypes and estrogen usage could be involved in arterial wall structural differences. The causality between CRP levels and cIMT remains unclear, and the observed difference in cIMT is not clinically relevant in the present state. Future larger and longitudinal studies may shed further light on the role of more long-term estrogen use and early atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02610-z.

Perinatal factors and high-sensitive C-reactive protein levels during adolescence

Objective

To examine whether perinatal factors are associated with low-grade inflammation measured by high-sensitivity C-reactive protein levels during adolescence.

Methods

Nested case-control study of 125 teenagers who were born by Cesarean delivery and had high-sensitivity C-reactive protein levels determined at 15–17 years. Data on obstetric and perinatal factors were recorded prospectively at the time of their birth.

Results

Median values of high-sensitivity C-reactive protein were significantly higher in teenagers, who were born as large for gestational age or with maternal diabetes compared to others (2.54 vs 0.34 mg/L; p < 0.024), and born during spring or summer compared to those born during winter or autumn (0.48 vs 0.27 mg/L; p < 0.023). No other perinatal associations were detected (for ex. such as electivity of operation, onset of labor, rupture of fetal membranes, cervical dilatation at delivery, gestational age, Apgar scores at 5 min, umbilical blood pH value, administration of neonatal antibiotics or need of neonatal intensive care treatment) in CRP levels. Further, teenagers with current body mass index in the highest tertile, regular medication for chronic disease and girls using oral contraceptives had significantly higher high-sensitivity C-reactive protein levels than others.

Conclusion

Prenatal exposures such as maternal metabolic environment and seasonality may have longterm effects on the low-grade inflammation and later cardiometabolic risks. Seasonality might be partly explained by maternal vitamin D levels during pregnancy, and thus future efforts are warranted to ensure sufficient vitamin D availability during pregnancy. Surprisingly, no other significant associations were detected between perinatal characteristics and high-sensitivity C-reactive protein levels.

Insight into the longitudinal relationship between chronic subclinical inflammation and obesity from adolescence to early adulthood: a dual trajectory analysis

OBJECTIVES AND DESIGN

This study aimed to understand the longitudinal relationship between C-reactive protein (CRP) and body mass index (BMI) from adolescence to early adulthood.

METHODS

CRP and BMI were collected from participants of the Raine Study Gen2 at 14-, 17-, 20- and 22-year follow-ups (n = 1312). A dual trajectory analysis was conducted to assess the association between CRP and BMI trajectories, providing conditional probabilities of membership of CRP trajectory membership given BMI trajectory membership. Best model fit was assessed by systematically fitting two to eight trajectory groups with linear and quadratic terms and comparing models according to the Bayesian Information Criterion statistic.

RESULTS

The three CRP trajectories were; "stable-low" (71.0%), "low-to-high" (13.8%) and "stable-high" (15.2%). Participants in a "high-increasing" BMI trajectory had a higher probability of being in the "stable-high" CRP trajectory (60.4% of participants). In contrast, individuals in the "medium-increasing" BMI trajectory did not have a significantly increased probability of being in the "stable-high" CRP trajectory.

CONCLUSIONS

These findings support that chronic sub-clinical inflammation is present through adolescence into early adulthood in some individuals. Targeting chronic sub-clinical inflammation though obesity prevention strategies may be important for improving future health outcomes.

Distribution and determinants of serum high-sensitivity C-reactive protein in Ethiopian population

BACKGROUND

C-reactive protein (CRP) is an important inflammatory marker associated with different disease conditions, and its concentration differs among ethnicity. This study aimed to determine the distribution and determinants of serum high-sensitive method CRP (hsCRP) that can measure the typically low concentrations, among the Ethiopian population, for which there is no data.

METHODS

A cross-sectional community-based study was conducted in April-June 2015. A total of 5162 individuals aged 15-69 were included. Behavioral, physical, and biochemical measurements were taken using the WHO STEPS non-communicable diseases (NCDs) risk factors assessment tool. Serum hsCRP was determined using Cobas Integra 400 Plus (Roche). Factors associated with hsCRP levels were also considered.

RESULTS

median hsCRP was 0.80 mg/L (Interquartile range, 0.19-2.12) (males: 0.91 mg/L, females: 0.74 mg/L). More than 18% of the study participants had hsCRP greater than 3 mg/L according to the American Heart Association and Centers for Diseases Control and Preventions cut off value. Higher BMI, living in Somali and in Dire Dawa region, and not consuming of fruit or vegetables were independent risk factors for high hsCRP levels.

CONCLUSION

Serum hsCRP levels distribution is comparable to other studies. Until now, no data have been reported in the literature about the Ethiopian population.

Systemic low-grade inflammation-associated lifestyle, diet, and genetic factors: A population-based cross-sectional study

OBJECTIVES

Systemic low-grade inflammation (SLGI) is an intermediary common condition to the physiopathology of chronic noncommunicable diseases and targeting its determinants could lead to more efficient public health strategies. We aimed to investigate SLGI-independent associations with lifestyle, diet, and genetic factors in a population-based sample of adults using a systemic low-grade inflammation score (SIS).

METHODS

The study sample is composed of 269 participants from the cross-sectional population-based Health Survey of Sao Paulo (2008-2010), ages 20 to 59 y, whose data on socioeconomic variables, lifestyle, health parameters, and blood samples were available. Diet was assessed by two 24-h recalls, and the Brazilian Health Eating Index-Revised (BHEI-R) was scored. From blood samples, 30 single nucleotide polymorphisms on inflammatory genes were genotyped, and plasma eleven inflammatory biomarkers levels that composed the SIS were determined. A multiple, stepwise, linear regression was used to investigate SIS-independent associated factors.

RESULTS

Factors independently associated with SIS were BHEI-R score (partial R² = 5.1; β = -0.13; P = 0.003), body mass index (partial R² = 3.4; β = 0.19; P = 0.001), TLR4 rs5030728 GA + AA genotype (partial R² = 3.1; β = -1.37; P = 0.008), age 50 to 59 y (partial R² = 2.5; β = 1.93; P = 0.029) in comparison with the reference category (20 to 29 y), and commuting physical activity >150 min/wk (partial R² = 2.2; β = -1.29; P = 0.043) after adjustment for current smoking status, medication use, and dietary misreporting.

CONCLUSIONS

Eating a lower quality diet, having a higher body mass index score and age, being GG homozygous for TLR4 rs5030728, and spending <150 min/wk in transportation physical activity are independent determinants of SLGI.

Correlations of C-Reactive Protein and Folate with Smoking, Sport, Hematological Inflammation Biomarkers and Anthropometrics in Syrian University Female Students Cross-Sectional Study

In Syria, high-Sensitive C-Reactive (hsCRP), folate, and, other health risk data in young women are limited. This cross-sectional study evaluates hsCRP and folate levels along with anthropometric characteristics, lifestyle factors and some biomarkers linked to cardiovascular disease (CVD) risk factors in healthy female students (n = 207, 18-25 years old). Among participants, hsCRP level was at average or high risk of CVD in 20.7% and 2.5% respectively and it was significantly higher in participants who had high body mass index (BMI) (Nonparametric statistical tests, p value < 0.05). Unexpectedly, it did not vary significantly between smokers and nonsmokers. And, it correlated positively with anthropometric and erythrocyte sedimentation rate (ESR) measurements. While folate level was low in 3.4% of participants, no association between hsCRP and folate levels was found. Finally, low hemoglobin level and habit of waterpipe smoking are spreading; and, sport practicing is shrinking. After reviewing similar works, this study suggests that the possible correlation between hsCRP and folate could be displayed in patients older than 30 years. Also, the marked decrease in hemoglobin level needs more attention. Finally, young females in Syria are advised to consider a lifestyle free of smoking and packed with physical activity.

Elevation of Oxidized Lipoprotein of Low Density in Users of Combined Oral Contraceptives

Background

The use of combined oral contraceptive (COC) has been related to changes in glycemic, lipid metabolism, increased oxidative stress, and systemic blood pressure, which could suggest a higher oxidation of low-density lipoprotein cholesterol (LDL-cholesterol) in women on use of COC.

Objective

To test the hypothesis that there is a difference in the plasma values of oxidized LDL among women who use and do not use COC, as well as to evaluate the correlation between it and the lipid profile and high-sensitivity C-reactive protein (hs-CRP).

Methods

Forty-two women with ages between 18 and 35 years old, who were eutrophic, irregularly active, with triglycerides < 150 mg/dL, blood glucose < 100 mg/dL, and who used or did not use COC were selected. These women were allocated in the COC group, formed by 21 women on COC use for at least 1 year; and a control group (CG), consisting of 21 women who had not used any type of hormonal contraceptive for at least 1 year. A significance level of 5% was adopted for statistical analyses.

Results

It was observed that GCOC showed higher values of oxidized LDL than the CG, respectively 384 mU/mL versus 283 mU/mL (p < 0.01). A positive correlation between oxidized LDL and LDL-cholesterol (r = 0.3, p < 0.05), with total cholesterol (r = 0.47, p < 0.01) and with triglycerides (r = 0.32, p < 0.03) was observed, and there was no correlation with the hs-CRP. In the categorized analysis of oxidized LDL, 71.4% of GCOC women, and 28.6% of the CG remained above the established cutoff point.

Conclusion

Women who use COC have higher plasma levels of oxidized LDL, and there is a positive correlation between oxidized LDL and other lipid variables.

C-Reactive Protein Correlates with Negative Symptoms in Patients with Schizophrenia

Peripheral and CNS-localized inflammatory processes are hypothesized to contribute to the complex pathophysiology of schizophrenia. Elevated levels of the acute phase reactant C-reactive protein (CRP) have been observed in schizophrenia, yet relatively few studies have investigated the association between this inflammatory biomarker and psychotic symptoms in schizophrenia. This study is a pilot cross-sectional analysis investigating the relation of plasma CRP levels and the positive and negative symptoms of schizophrenia (the primary aim), assessed by the Positive and Negative Syndrome Scale (PANSS). A secondary analysis was also performed evaluating the potential association of CRP with cognitive function using the NIH Toolbox Cognitive Test Battery. After adjusting for age, sex, race, and body mass index, a positive correlation was observed between CRP and PANSS negative symptoms (rho = 0.37, p = 0.05). There was no correlation between plasma CRP and any of the NIH Toolbox measures of cognitive function in the unadjusted or adjusted analyses. Though limited by a relatively small sample size and the unavailability of longitudinal data, the correlation between CRP and psychopathology in this sample of patients supports a role for inflammation in the pathophysiology of schizophrenia.

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.

Association of lifestyle, inflammatory factors, and dietary patterns with the risk of suffering a stroke: A case-control study

BACKGROUND

Lifestyle, including dietary patterns, could involve specific factors participating in inflammation that confer a higher risk of suffering a stroke. However, little attention has been apparently given to habitual food consumption in patients suffering a cerebrovascular event.

OBJECTIVE

To assess the influence of dietary habits as well as other lifestyle-related variables on the risk of suffering a stroke.

DESIGN

A case-control study was designed. Fifty-one cases (age: 59.1 ± 9.1y.o; BMI; 30.8 ± 3.4 kg/m²) and 51 controls (age: 61.1 ± 9.1y.o; BMI; 30.4 ± 3.6 kg/m²) were enrolled in the study. Anthropometric and body composition variables were measured. Dietary information was obtained from a validated food frequency questionnaire. Physical activity and lifestyle-related factors were assessed. Blood samples were drawn.

RESULTS

Patients suffering a stroke showed higher prevalence of diabetes (30 vs. 7.7%; P = 0.020) and hypertension (74.5 vs. 40.3%; P < 0.001) and were less physically active (36.7 vs. 66.6%; P = 0.024) than controls. Patients registered worse glucose and lipid profiles, higher levels of hepatic biomarkers, and higher blood cell counts than controls. Stroked patients showed lower adherence to a statistically derived healthy dietary pattern than controls (23.5 vs. 42.3%; P = 0.017). A logistic regression model was built up considering hypertension, diabetes, smoking, physical activity, adherence to a 'healthy dietary pattern' and C-reactive protein concentration. The final model strongly associated with the risk of suffering a stroke (R²: 44.6%; P_model < 0.0001).

CONCLUSION

Lifestyle variables such as physical activity, smoking habit, and a dietary pattern including foods with low inflammatory potential play an important role in the reduction of the risk of suffering a stroke.

The Combined Impact of Neutrophil-to-Lymphocyte Ratio and Type 2 Diabetic Mellitus on Significant Coronary Artery Disease and Carotid Artery Atherosclerosis

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has recently emerged as a new important inflammatory marker for predicting cardiovascular events. This study aimed to evaluate the combined impact of NLR and type 2 diabetes mellitus (T2DM) on significant coronary artery disease (CAD) and carotid artery atherosclerosis.

METHODS

This study includes a total of 828 patients evaluated by coronary angiography and carotid ultrasonography. Significant CAD was defined as at least one vessel with stenosis greater than 50%. We employed logistic regression models to investigate the association of NLR and T2DM with significant CAD. The goodness-of-fit and discriminability of the models were assessed by the loglikelihood ratio test and C-index, respectively. Also, we investigated the clinical relevance of the categorized NLR that classifies patients into three risk groups (low, intermediate, high).

RESULTS

According to logistic regression analysis, both NLR {adjusted odds ratio (OR) 1.31, p < 0.001} and T2DM (adjusted OR 2.46, p = 0.006) were independent risk factors of significant CAD. The addition of NLR and T2DM into a logistic regression model including conventional cardiovascular risk factors significantly improved the goodness-of-fit (p < 0.001) and the discriminability of the model (p = 0.004). Also, T2DM patients assigned into the high risk group (NLR > 2) showed the greater prevalence of significant CAD and carotid artery atherosclerosis compared with patients without T2DM or type 2 diabetic patients assigned into the low risk group (NLR ≤ 1).

CONCLUSION

Our results suggest that type 2 diabetic patients with high inflammatory state would be more vulnerable to significant CAD and carotid artery atherosclerosis.

Combined oral contraception and obesity are strong predictors of low-grade inflammation in healthy individuals: results from the Danish Blood Donor Study (DBDS)

BACKGROUND

C-reactive protein (CRP) is a well-established marker of inflammation. The level of CRP is affected by several lifestyle factors. A slightly increased CRP level, also known as low-grade inflammation (LGI), is associated with increased risk of several diseases, especially cardiovascular disease. The aim of this study was to identify predictors of increased CRP levels in healthy individuals. We therefore assessed CRP in a large cohort of blood donors.

METHODS

We measured plasma CRP levels in 15,684 participants from the Danish Blood Donor Study. CRP was measured by a commercial assay. Furthermore, all participants completed a standard questionnaire on smoking status, alcohol consumption, physical activity, diet, and various body measurements. Female participants also reported the use of contraception, childbirth, and menopausal status. The relationship between LGI (defined here as a plasma CRP level between 3 mg/L and 10 mg/L) and predictors was explored by multivariable logistic regression analysis. Results were presented as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

We found LGI in a total of 1,561 (10.0%) participants. LGI was more frequent in women using combined oral contraception (OC) (29.9%) than in men (6.1%) and women not using OC (7.9%). Among premenopausal women, OC was the strongest predictor of LGI (odds ratio = 8.98, p<0.001). Additionally, body mass index (BMI) and waist circumference were positively associated with LGI.

CONCLUSION

High BMI and abdominal obesity strongly predicted LGI among healthy individuals. However, the most striking finding was the high prevalence of LGI among premenopausal women who used combined oral contraception. Although the significance of CRP as a marker of inflammation is well known, the role of CRP in pathogenesis is still uncertain. The impact of oral contraception on CRP levels should nevertheless be considered when CRP is used in risk assessment.

Distribution and determinants of C-reactive protein in the older adult population: European Prospective Investigation into Cancer-Norfolk study

BACKGROUND

C-reactive protein (CRP) is a well-documented predictor of cardiovascular diseases and mortality. We aimed to better understand the distribution and determinants of CRP in the population.

MATERIALS AND METHODS

Study participants were men and women aged 40-79 in the UK-based EPIC-Norfolk population-based cohort study. CRP was measured in 18 586 available serum samples (8334 men and 10 252 women) and remeasured in 6087 individuals on average 13 years later using a high-sensitivity assay.

RESULTS

In cross-sectional analyses, the range of serum CRP was 0.1-188.3 mg/L and the median 1.6 mg/L. A third of the population had serum CRP levels above 3 mg/L. Serum CRP levels were comparable in men and women who were not taking postmenopausal hormone replacement therapy (HRT). Women who were taking HRT had double CRP levels compared with HRT nonusers. Smoking was also strongly related to CRP in men and women. Serum CRP was positively and independently associated with age, body mass index and waist circumference and inversely with height. A stronger association with serum CRP measured concurrently than on average 13 years later indicated a short-term rather than long-term association with smoking and HRT use. Social class and alcohol intake were not independently related to CRP, but there was a strong inverse association with educational status.

CONCLUSION

The distribution of serum CRP in the population is similar in men and women after taking into account smoking and HRT use. Anthropometric factors as well as educational status are strongly related to serum CRP.

Basal, circadian, and acute inflammation in normal versus overweight men

Increased inflammation is present in obese compared with normal weight individuals, but inflammation characteristics of nonobese, overweight individuals are less clear.

PURPOSE

The objective of this study was to determine whether basal, circadian, and posteccentric exercise inflammation levels differ between normal and overweight men.

METHODS

Men (18-35 yr old) classified as normal weight (body mass index ≤25 kg·m, n = 20) and overweight (body mass index = 25-30 kg·m, n = 10) completed exercise (EX) and control (CON) conditions in random order. Maximal voluntary effort and eccentric actions (3 × 15) using the elbow flexor muscles of one arm were performed, and blood was collected preexercise and 4, 8, 12, and 24 h postexercise at 7:00 a.m., 12:00 p.m., 4:00 p.m., 8:00 p.m., and 7:00 a.m. Blood was collected on a time-matched schedule without exercise for CON. Soluble tumor necrosis factor receptor-1, interleukin-6, C-reactive protein (CRP), and cortisol responses (EX value - time-matched CON value) were measured.

RESULTS

Basal CRP was higher in the overweight compared with normal weight group (mean ± SD, 0.542 ± 0.578 vs 1.395 ± 1.041 mg·L). Soluble tumor necrosis factor receptor-1 increased (P < 0.05) 8 h postexercise in both groups, and the response was greater 12 and 24 h postexercise in the overweight compared with normal weight groups. Interleukin-6 increased (P < 0.05) 8 h postexercise, with a trend (P = 0.09) to be greater in the overweight group. CRP and cortisol responses were not detected.

CONCLUSIONS

The low-grade inflammation state in overweight compared with normal weight men includes both higher basal CRP concentrations and enhanced acute inflammation, but not in changes to the circadian patterns of cortisol and inflammation variables.

A consideration of biomarkers to be used for evaluation of inflammation in human nutritional studies

To monitor inflammation in a meaningful way, the markers used must be valid: they must reflect the inflammatory process under study and they must be predictive of future health status. In 2009, the Nutrition and Immunity Task Force of the International Life Sciences Institute, European Branch, organized an expert group to attempt to identify robust and predictive markers, or patterns or clusters of markers, which can be used to assess inflammation in human nutrition studies in the general population. Inflammation is a normal process and there are a number of cells and mediators involved. These markers are involved in, or are produced as a result of, the inflammatory process irrespective of its trigger and its location and are common to all inflammatory situations. Currently, there is no consensus as to which markers of inflammation best represent low-grade inflammation or differentiate between acute and chronic inflammation or between the various phases of inflammatory responses. There are a number of modifying factors that affect the concentration of an inflammatory marker at a given time, including age, diet and body fatness, among others. Measuring the concentration of inflammatory markers in the bloodstream under basal conditions is probably less informative compared with data related to the concentration change in response to a challenge. A number of inflammatory challenges have been described. However, many of these challenges are poorly standardised. Patterns and clusters may be important as robust biomarkers of inflammation. Therefore, it is likely that a combination of multiple inflammatory markers and integrated readouts based upon kinetic analysis following defined challenges will be the most informative biomarker of inflammation.

Developing and assessing cardiovascular biomarkers

Atherosclerosis is a slow process that over time can lead to fatal events. Early identification and prediction of future risk can allow for preventive strategies to be instituted. There is an increasing interest in utilizing novel biomarkers in cardiovascular disease screening and management. These novel biomarkers may help in cardiovascular disease risk assessment and treatment monitoring, and some may be treatment targets. To be useful for risk prediction, novel biomarkers need to show a significant association with cardiovascular disease events and bring additional value in risk stratification when added to known risk prediction models. Biomarkers used for treatment monitoring need to show that they can serve as good surrogates of cardiovascular disease status. In this article, we present 3 biomarkers that are currently approved by the U.S. Food and Drug Administration for use in cardiovascular disease management and risk assessment: C-reactive protein, lipoprotein-associated phospholipase A2, and myeloperoxidase. Other new biomarkers have also been shown recently to help in cardiovascular disease risk prediction and management. In this article, we will review 2 of these new biomarkers: cardiac troponin T measured by a highly sensitive assay and brain natriuretic peptide.

Hormonal contraceptive use among adolescent girls in Germany in relation to health behavior and biological cardiovascular risk factors

PURPOSE

To determine the association between hormonal contraceptive (HC) use, and behavior-related and biological cardiovascular risk factors among teenage girls in Germany.

METHODS

HC use was assessed among 2,285 girls aged 13-17 years who participated in the health survey for children and adolescents (German Health Interview and Examination Survey for Children and Adolescents, KiGGS), between years 2003 and 2006. Prevalence of HC use was determined according to sociodemographic variables, behavior-related health risks, and overweight status. We compared HC users and nonusers with respect to biological cardiovascular risk factors, including systolic and diastolic blood pressure, and serum concentrations of lipids, lipoproteins, high sensitivity C-reactive protein (hs-CRP), and homocysteine.

RESULTS

HC users were more likely than nonusers to combine several behavior-related health risks, independent of sociodemographic factors. In particular, HC use was strongly associated with current smoking (odds ratio: 3.4, 95% confidence interval: 2.7-4.3). HC use and behavioral factors showed an additive effect on biological cardiovascular risk factors, explaining between 6% and 30% of the population variance. Relative contributions of HC use ranged from <1% for systolic and diastolic blood pressure to 12% for hs-CRP.

CONCLUSIONS

HC use among 13-17-year-old girls in Germany is significantly correlated with a more unfavorable cardiovascular risk profile, which is partly explained by a clustering of behavioral risk factors among HC users. When prescribing HC to teenagers, physicians should systematically assess avoidable behavioral cardiovascular risk factors and provide counseling tailored to the risk profile of the individual patient.

Association of high-sensitivity C-reactive protein with de novo major depression

BACKGROUND

Although there is cross-sectional evidence that changes in the immune system contribute to the pathophysiology of depression, longitudinal data capable of elucidating cause and effect relationships are lacking.

AIMS

We aimed to determine whether subclinical systemic inflammation, as measured by serum high-sensitivity C-reactive protein (hsCRP) concentration, is associated with an increased risk of de novo major depressive disorder.

METHOD

Major depressive disorder was diagnosed using a clinical interview (SCID-I/NP). This is a retrospective cohort study; from a population-based sample of 1494 randomly selected women recruited at baseline during the period 1994-7, 822 were followed for a decade and provided measures of both exposure and outcome. Of these women, 644 (aged 20-84 years) had no prior history of depression at baseline and were eligible for analysis.

RESULTS

During 5827 person-years of follow-up, 48 cases of de novo major depressive disorder were identified. The hazard ratio (HR) for depression increased by 44% for each standard deviation increase in log-transformed hsCRP (ln-hsCRP) (HR = 1.44, 95% CI 1.04-1.99), after adjusting for weight, smoking and use of non-steroidal anti-inflammatory drugs. Further adjustment for other lifestyle factors, medications and comorbidity failed to explain the observed increased risk for depression.

CONCLUSIONS

Serum hsCRP is an independent risk marker for de novo major depressive disorder in women. This supports an aetiological role for inflammatory activity in the pathophysiology of depression.

Physical activity, exercise and low-grade systemic inflammation

Prospective studies have shown that chronic low-grade inflammation may contribute to the pathogenesis of the most common chronic diseases and in particular CVD. Obesity has repeatedly been associated with moderately raised levels of inflammation, and this observation has led to the view that obesity is characterised by a state of chronic low-grade inflammation. There is now great interest in elucidating how physical activity and exercise modulate inflammation. This review summarises the current research addressing the influence of physical activity and exercise in mitigating the risks of obesity and diseases such as type-II diabetes and CVD, through its action on the low-grade inflammatory state. Most research on this topic hypothesised that the association between physical activity and inflammatory markers is independent of fatness, but very few studies have proven this. Given that physical activity and obesity are often inversely related, it is not clear as to whether the anti-inflammatory health benefits of a physically active lifestyle are due to exercise per se or result from favourable changes in the body composition.

Association of posttraumatic stress disorder with low-grade elevation of C-reactive protein: evidence from the general population

BACKGROUND

Posttraumatic stress disorder (PTSD) has been associated with several somatic diseases, and low-grade inflammation may be one psychobiological mechanism mediating this relationship. We assessed the association between PTSD and elevated serum levels of C-reactive protein (CRP; >3mg/L) in a large general population sample.

METHODS

About 3049 adults living in the community were included in the present study. CRP, lipoproteins and triglycerides were determined. Participants were also examined with regard to blood pressure, body mass index (BMI), physical activity, comorbid somatic diseases, medication, daily alcohol intake, and depression.

RESULTS

PTSD was diagnosed in 55 participants (1.8%), and low-grade inflammation (i.e. CRP >3mg/L) was found in 701 subjects (23.0%). PTSD positive participants had significantly higher odds for elevated CRP values than those without PTSD (OR=2.27; 95% CI: 1.32-3.93). Even after adjusting for sex, age, other sociodemographic factors, BMI, blood pressure, lipoproteins and triglycerides, physical activity, comorbid somatic diseases, daily alcohol intake, and trauma exposure, there were almost twofold higher odds for elevated CRP levels in participants with PTSD compared to those without PTSD (OR=1.87; 95% CI: 1.05-3.35).

CONCLUSIONS

Our findings suggest a close relationship between PTSD and low-grade inflammation possibly representing one psychobiological pathway from PTSD to poor physical health, particularly with respect to cardiovascular and pulmonary disease as well as diabetes.

Low-grade, systemic inflammation in adolescents: association with early-life factors, gender, and lifestyle

Low-grade, systemic inflammation is related to increased risk of cardiovascular disease in adults. The proinflammatory state tracks from adolescence to adulthood. Identifying correlates of inflammation in adolescents could provide opportunities to prevent cardiovascular disease in adulthood. However, population-based data on correlates of inflammation in adolescence are limited. Therefore, the authors studied the associations of early-life factors, gender, and lifestyle with inflammation (measured by high-sensitivity C-reactive protein and leukocyte count) at age 16 years (2001-2002) in the prospective, population-based Northern Finland Birth Cohort 1986 Study (n = 5,240). In females, being born small for gestational age and current use of oral contraceptives were associated with the proinflammatory state. The association of birth size with inflammation was not observed in males. In logistic regression analyses, oral contraceptive use (odds ratio (OR) = 2.83), abdominal obesity (OR = 5.17), and smoking (OR = 2.72) were associated with elevation of both inflammation markers in females; abdominal obesity (OR = 5.72) and smoking (OR = 2.02) were associated in males. Thus, females appear more susceptible to the adverse effects of being born small for gestational age than males. Given the widespread use of oral contraceptives and the potential pathophysiologic consequences of the proinflammatory state, the association of oral contraceptive use with inflammation in adolescence may have public health implications.

Proinflammatory cytokines in CRP baseline regulation

Low-grade inflammation, a minor elevation in the baseline concentration of inflammatory markers such as C-reactive protein (CRP), is nowadays recognized as an important underlying condition in many common diseases. Concentrations of CRP under 10 mg/1 are called low-grade inflammation and values above that are considered as clinically significant inflammatory states. Epidemiological studies have revealed demographic and socioeconomic factors that associate with CRP concentration; these include age, sex, birth weight, ethnicity, socioeconomic status, body mass index (BMI), fiber consumption, alcohol intake, and dietary fatty acids. At the molecular level, production of CRP is induced by proinflammatory cytokines IL-1, IL-6, and IL-17 in the liver, although extra hepatic production most likely contributes to systemic concentrations. The cytokines are produced in response to, for example, steroid hormones, thrombin, C5a, bradykinin, other cytokines, UV-light, neuropeptides and bacterial components, such as lipopolysaccharide. Cytokines exert their biological effects on CRP by signaling through their receptors on hepatic cells and activating different kinases and phosphatases leading to translocation of various transcription factors on CRP gene promoter and production of CRP protein. Genetic polymorphisms in the interleukin genes as well as in CRP gene have been associated with minor elevation in CRP. As minor elevation in CRP is associated with both inflammatory and noninflammatory conditions, it should be noticed that the elevation might just reflect distressed or injured cells homeostasis maintenance in everyday life, rather than inflammation with classical symptoms of redness, swelling, heat, and pain.

Serum IGF-I and C-reactive protein in healthy black and white young men: the CARDIA male hormone study

OBJECTIVE

Animal and human studies suggest that C-reactive protein (CRP) may be inversely associated with serum insulin-like growth factor-I (IGF-I) concentrations. However, most human studies have not controlled adequately for confounding factors, particularly nutritional intake. This population-based study examined whether CRP is inversely associated with IGF-I and IGFBP-3 concentrations.

METHODS

In cross-sectional analysis, multivariable linear regression with adjustment for age, BMI, smoking status, alcohol intake, and nutritional factors was used to relate log CRP, the independent variable, to IGF-I and IGFBP-3 in a sample of black (n=364) and white men (n=486) separately by race.

RESULTS

Only black men had positive findings: log CRP was significantly associated with IGF-I (beta=-13.1 ng/ml, p=0.02) and the difference in mean IGF-I concentrations between the highest and lowest quartiles of CRP was 26 ng/ml. There was a statistically significant interaction between log CRP and smoking status (p=0.02); the regression coefficient for IGF-I predicted from log CRP was significant in smokers (beta=-39.8 ng/ml, p=0.0001), but not in non-smokers. The difference in mean IGF-I concentrations between highest and lowest quartiles of CRP was 100 ng/ml for black smokers. There were no associations for IGFBP-3.

CONCLUSIONS

In our study, CRP levels are inversely associated with IGF-I concentrations in black male smokers; however, the causal nature of the association is unclear and should be studied further.

Serum amyloid A is independently associated with metabolic risk factors but not with early atherosclerosis: the Cardiovascular Risk in Young Finns Study

BACKGROUND

Serum amyloid A (SAA) is a sensitive marker of inflammation and its elevation has been implicated in obesity and in cardiovascular disease, yet data on its regulation in young adults or on its role in early atherosclerosis is scarce. We investigated which factors explain the variation in SAA and analysed whether SAA could be associated with preclinical atherosclerosis.

METHODS

Serum amyloid A levels were measured in participants of the Cardiovascular Risk in Young Finns Study (n = 2280, n = 1254 women, n = 1026 men). Correlates and determinants of SAA were analysed and the effect of SAA on subclinical atherosclerosis, measured as intima-media thickness (IMT) and carotid artery compliance, was evaluated with risk-factor adjusted models.

RESULTS

Serum amyloid A correlated directly and independently of BMI with C-reactive protein (CRP), waist circumference and leptin in both sexes, with total cholesterol, LDL cholesterol and ApolipoproteinA1 (ApoA1) in women and with triglycerides, insulin levels and insulin resistance in men. Use of combined oral contraceptives and intrauterine device was also associated with SAA levels. Determinants for SAA included CRP, leptin and ApoA1 in women, and CRP, leptin and HDL cholesterol in men. SAA levels correlated with carotid compliance in both sexes and with IMT in men, yet SAA had no independent effect on IMT or carotid compliance in multivariable analysis.

CONCLUSIONS

Serum amyloid A was associated with several metabolic risk factors but was not an independent predictor of IMT or carotid artery compliance. Further longitudinal studies will show whether SAA holds a prognostic value as a risk marker, analogously to CRP.

Flow mediated vasodilation and circulating concentrations of high sensitive C-reactive protein, interleukin-6 and tumor necrosis factor-alpha in normal pregnancy--The Cardiovascular Risk in Young Finns Study

BACKGROUND

Traditional risk factors such as hyperlipidemia induce a state of inflammation that impairs vascular function. Despite marked maternal hyperlipidemia, endothelial function improves during pregnancy. In non-pregnant state increased circulating levels of pro-inflammatory cytokines and high sensitive C-reactive protein (hsCRP) lead to attenuated flow mediated vasodilation. Relation between endothelial function and pro-inflammatory cytokines has not been studied thoroughly in pregnancy. The aim of this study was to evaluate the effect of pregnancy on hsCRP and pro-inflammatory cytokines and their associations with vascular endothelial function.

METHODS

As part of population-based, prospective cohort Cardiovascular Risk in Young Finns study conducted in Finland we measured brachial artery flow mediated dilation (FMD) and serum concentrations of hsCRP, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in 57 pregnant Finnish women throughout gestation and 62 control women matched for age and smoking.

RESULTS

HsCRP-concentration was greater in pregnancy compared to non-pregnant controls (median hsCRP 2.52 mg l(-1) versus 1.21 mg l(-1), P<0.001). IL-6-concentration was slightly increased in pregnancy compared with the non-pregnant controls (median 1.66 versus 1.32 mg l(-1), non-significant [NS]) and TNF-alpha-concentration was slightly decreased in pregnant group (2.11 versus 2.38 pg ml(-1), NS). FMD increased during pregnancy and IL-6 had a positive correlation to the FMD in pregnancy (R = 0.288, P = 0.031).

CONCLUSIONS

Improvement of FMD in normal pregnancy was not affected by increase in hsCRP concentration. We found an association with IL-6 and FMD but we believe that improvement in endothelial function during normal pregnancy is not caused by variation in hsCRP, IL-6 or TNF-alpha.

Depressive symptoms and the metabolic syndrome in childhood and adulthood: a prospective cohort study

OBJECTIVE

To examine the reciprocal associations between depressive symptoms and clinical definitions of the metabolic syndrome in childhood and adulthood.

DESIGN

Population-based prospective cohort study of 921 participants (538 women and 383 men) in Finland. The components of the metabolic syndrome were measured in childhood (mean age 12 years) and again in adulthood (mean age 33 years). A revised version of the Beck Depression Inventory was used to assess depressive symptoms at the mean ages of 24 and 33.

MAIN OUTCOME MEASURES

Metabolic syndrome defined by the National Cholesterol Education Program Adult Treatment Panel III (NCEP), the European Group for the Study of Insulin Resistance, and the International Diabetes Federation criteria.

RESULTS

In women, depressive symptoms were associated with increased risk of the metabolic syndrome in adulthood (odds ratio for NCEP metabolic syndrome per 1 SD increase in depressive symptoms 1.40, 95% confidence interval 1.05-1.85). The metabolic syndrome in childhood, in turn, predicted higher levels of depressive symptoms in adulthood (p = .03). In men, no associations were found between depressive symptoms and the clinical definitions of the metabolic syndrome.

CONCLUSION

The process linking depressive symptoms with the metabolic syndrome may go into both directions and may begin early in life.

Correlates of C-reactive protein levels in young adults: a population-based cohort study of 3827 subjects in Brazil

The socio-demographic, behavioral and anthropometric correlates of C-reactive protein levels were examined in a representative young adult Brazilian population. The 1982 Pelotas Birth Cohort Study (Brazil) recruited over 99% of births in the city of Pelotas that year (N = 5914). Individuals belonging to the cohort have been prospectively followed up. In 2004-2005, 77.4% of the cohort was traced, members were interviewed and 3827 individuals donated blood. Analyses of the outcome were based on a conceptual model that differentiated confounders from potential mediators. The following independent variables were studied in relation to levels of C-reactive protein in sex-stratified analyses: skin color, age, family income, education, parity, body mass index, waist circumference, smoking, fat/fiber/alcohol intake, physical activity, and minor psychiatric disorder. Geometric mean (95% confidence interval) C-reactive protein levels for the 1919 males and 1908 females were 0.89 (0.84-0.94) and 1.96 mg/L (1.85-2.09), respectively. Pregnant women and those using oral contraceptive therapies presented the highest C-reactive protein levels and all sub-groups of women had higher levels than men (P < 0.001). Significant associations between C-reactive protein levels were observed with age, socioeconomic indicators, obesity status, smoking, fat and alcohol intake, and minor psychiatric disorder. Associations were stronger at higher levels of C-reactive protein and some associations were sex-specific. We conclude that both distal (socio-demographic) and proximal (anthropometric and behavioral) factors exert strong effects on C-reactive protein levels and that the former are mediated to some degree by the latter.

Effects of third-generation oral contraceptives on high-sensitivity C-reactive protein and homocysteine in young women

OBJECTIVE

To evaluate the effect of third-generation oral contraceptives on high-sensitivity C-reactive protein (CRP), homocysteine, and lipids levels in a population of young, fertile, nonobese women.

METHODS

Blood markers were evaluated in 277 healthy white women (mean age 23 years and mean body-mass index 21 kg/m(2)). Seventy-seven oral contraceptive users were compared with 200 non-oral contraceptive users. Progressive cutoffs of high-sensitivity CRP and homocysteine levels were examined.

RESULTS

Levels of high-sensitivity CRP posing a high risk of cardiovascular disease (3.0 to less than 10.0 mg/L) were found in 27.3% of oral contraceptive users and in 8.5% of non-oral contraceptive users (odds ratio 4.04; 95% confidence interval [CI] 1.99-8.18). Levels of high-sensitivity CRP at intermediate risk (1.0 to less than 3.0 mg/L) were found in 32.5% of oral contraceptive users and in 11.0% of non-oral contraceptive users (odds ratio 3.89; 95% CI 2.03-7.46). Notably, non-oral contraceptive users were 8.65 (95% CI 4.39-17.1) times as likely to demonstrate a protective level of high-sensitivity CRP (less than 0.5 mg/L) compared with oral contraceptive users. Oral contraceptive use increased serum triglycerides (P<.001) and total cholesterol P=.001); however, high-density lipoprotein, not low-density lipoprotein, contributed to this increase. A decreased ratio of low-density lipoprotein to high-density lipoprotein cholesterol was observed in oral contraceptive users compared with nonusers (P=.016). Oral contraceptive use did not affect homocysteine levels.

CONCLUSION

Third-generation oral contraceptive use increases low-grade inflammatory status measured by high-sensitivity CRP concentrations. Alteration of inflammatory status in oral contraceptive users could affect the risk of venous thromboembolism, cardiovascular disease, and other oral contraceptive-associated adverse conditions in young women.

Effects of the progestagen-only contraceptive implant Implanon on cardiovascular risk factors

OBJECTIVE

Epidemiological studies on the cardiovascular risk of progestagen-only contraceptives are rare. With the present study we aimed to investigate the effect of the low-dose etonogestrel-releasing contraceptive implant Implanon on cardiovascular risk factors, including markers of inflammation.

DESIGN

Longitudinal study.

SETTING

Family planning centre of a University Hospital.

SUBJECTS

Thirty-six healthy, nonsmoking women with regular cycles (n = 18 controls without hormonal contraception; n = 18 cases requesting the insertion of Implanon.

MEASUREMENTS

Blood samples for the determination of C-reactive protein (CRP), nitric oxide (NO), sex hormones and plasma lipids were taken in the early follicular phase of the cycle in both groups. A second sample was taken 12 weeks after Implanon insertion or in the controls during the early follicular phase of cycle 4.

RESULTS

Implanon treatment caused a 36% decrease in CRP (P < 0.06) and a significant decrease in high density lipoprotein (HDL) (P < 0.007), low density lipoprotein (LDL) (P < 0.001), cholesterol (P < 0.001), testosterone (P < 0.05) and SHBG (P < 0.002). Levels of NO, oestradiol and progesterone were not affected in either group. The cholesterol/HDL ratio did not change in Implanon carriers. There was a significant correlation between the cardiovascular risk factors CRP, cholesterol/HDL ratio and NO.

CONCLUSION

The progestagen-only implant Implanon does not exert a negative effect on the cardiovascular risk factors CRP, cholesterol/HDL ratio and NO. These results suggest that the use of a progestagen-only contraception does not increase cardiovascular risk factors in healthy young women.

Prevalence and risk factor correlates of elevated C-reactive protein in an adult Australian population

Measurement of the inflammatory biomarker C-reactive protein (CRP) is advocated for coronary heart disease risk assessment. The distribution and correlates of CRP in the general population should be known before it is used in clinical practice. CRP was measured in 1,761 men and 2,248 women aged 25 to 84 years who attended the 1994/1995 Busselton Health Survey. Prevalences of increased CRP >3 mg/L for age groups 25 to 39, 40 to 59, and 60 to 84 years were 15.7%, 20.6%, and 38.7%, respectively, in men and 21.2%, 22.1%, and 33.7%, respectively, in women not on hormone therapy. Logistic regression analysis identified independent predictors of increased CRP in men as obesity (odds ratio [OR] 3.5, 95% confidence interval [CI] 2.4 to 5.0), smoking (OR 3.1, 95% CI 2.1 to 4.5), hypertension (OR 1.6, 95% CI 1.1 to 2.3), and low high-density lipoprotein cholesterol (OR 1.4, 95% CI 1.0 to 1.8). In women, predictors were obesity (OR 7.8, 95% CI 5.8 to 10.6), hypertension (OR 1.4, 95% CI 1.0 to 1.9), high triglycerides (OR 1.6, 95% CI 1.1 to 2.4), vigorous exercise (OR 0.7, 95% CI 0.5 to 0.9), oral contraceptive use (OR 4.6, 95% CI 3.3 to 6.5), and hormone replacement therapy (OR 2.8, 95% CI 1.9 to 4.0). Overall, risks of increased CRP attributable to the presence of an abnormal or borderline coronary heart disease risk factor were 59% for men and 64% for women. In conclusion, despite gender-related differences in cardiovascular risk, increased CRP occurred commonly in men and women. Because increased CRP was largely attributable to conventional coronary heart disease risk factors, measurement of CRP may have limited utility for risk screening and primary prevention.

The influence of smoking and homocysteine on subclinical atherosclerosis is modified by the connexin37 C1019T polymorphism - The Cardiovascular Risk in Young Finns Study

BACKGROUND

A polymorphism C1019T on the connexin37 (Cx37) gene has been found to associate with coronary artery disease. There are conflicting results on which allele confers risk, and the possibility of interactions between the polymorphism and risk factors has been raised. In this study, we examined interactions between the Cx37 polymorphism and common risk factors and their associations to early vascular parameters of atherosclerosis: carotid artery intima-media thickness (IMT), and carotid artery compliance (CAC) and brachial artery flow mediated dilatation (FMD).

METHODS

A population of 1440 healthy young adults from the Cardiovascular Risk in Young Finns Study was studied. The subjects were genotyped and their cardiovascular risk factor and ultrasound data gathered in 2001 were used for the statistical analyses.

RESULTS

In the whole population, homocysteine in subjects with the TT genotype was found to be associated with higher FMD values (p for interaction 0.038) and remained so in three different adjusted models (p for interaction 0.022-0.038). In women with the CC genotype, smoking was found to be associated with higher FMD values and the smoking-by-genotype interaction remained significant in three adjusted models (p for interaction 0.001-0.041). In women with TT genotype, the effect of smoking was opposite, i.e., FMD values for smokers were lower compared to non-smokers. In men, physical activity interacted with Cx37 on CAC in the CT and TT genotypes (p for interaction 0.011). No significant interactions were found to predict IMT.

CONCLUSIONS

The effect of smoking and homocysteine levels on arterial endothelial functions and elasticity were modified by the allelic variation of the Cx37 gene. These data suggest that variation in the connexin gene may modify effects risk factors have on vascular function.

Relationship between leptin and C-reactive protein in young Finnish adults

CONTEXT

Leptin and C-reactive protein (CRP) concentrations are increased in inflammation, and both have been linked to increased risk for cardiovascular diseases.

OBJECTIVE

The objective of the study was to explore in a population-based sample whether the relation between leptin and CRP is independent of obesity level and whether genetic causes of CRP elevation contribute to leptin levels.

DESIGN

This was a population-based study including 1862 young adults (971 women; 891 men) aged 24-39 yr.

SETTING

The study was conducted at five centers in Finland.

MAIN OUTCOME MEASURES

Associations between leptin and CRP adjusted for obesity indices, risk factors, genetic variables, and lifestyle variables were measured.

RESULTS

Women had 3.0-fold higher median concentrations of leptin (12.5 vs. 4.1 ng/ml) and 1.3-fold higher median concentrations of CRP (0.75 vs. 0.56 mg/liter) than men (P < 0.0001 in both comparisons). In univariate analyses, CRP and leptin were significantly intercorrelated (r = 0.47, P < 0.0001 for women; r = 0.46, P < 0.0001 for men). In multiple regression analysis including age, body mass index, waist circumference, insulin, lipids, systolic and diastolic blood pressures, smoking status, and use of oral contraceptives in women, leptin was the main determinant of CRP in men (P < 0.0001) and the second most important determinant in women (P < 0.0001). A Mendelian randomization test based on genetic variants in the CRP gene (five single nucleotide polymorphisms) provided no support for CRP as a causal agent for leptin.

CONCLUSIONS

Leptin, obesity, and oral contraceptive use in women were the main factors related to CRP. The relation between leptin and CRP was independent of obesity and cardiovascular risk factors.

Hormonal and nutritional effects on cardiovascular risk markers in young women

CONTEXT

Cardiovascular (CV) risk markers, including high-sensitivity C-reactive protein (hsCRP), are increasingly important in predicting cardiac events. A favorable CV risk profile might be expected in anorexia nervosa (AN) due to low body weight and dietary fat intake. However, women with AN have decreased IGF-I levels reflecting decreased GH action, and IGF-I deficiency is associated with elevated hsCRP. Moreover, oral estrogens, known to increase hsCRP in other populations, are commonly prescribed in AN. To date, hsCRP levels and their physiological determinants have not been reported in women with AN.

OBJECTIVE

We examined the relationship between CV risk markers, undernutrition, IGF-I, and oral estrogens, specifically hypothesizing that in the setting of undernutrition, AN would be associated with low hsCRP despite low IGF-I levels and that those women taking oral contraceptive pills (OCPs) would have higher hsCRP and lower IGF-I levels.

DESIGN AND SETTING

We conducted a cross-sectional study at a clinical research center.

STUDY PARTICIPANTS

Subjects included 181 women: 140 women with AN [85 not receiving OCPs (AN-E) and 55 receiving OCPs (AN+E)] and 41 healthy controls [28 not receiving OCPs (HC-E) and 13 receiving OCPs (HC+E)].

MAIN OUTCOME MEASURES

We assessed hsCRP, IL-6, IGF-I, low-density lipoprotein (LDL), and high-density lipoprotein (HDL).

RESULTS

Despite low weight, more than 20% of AN+E had high-risk hsCRP levels. AN+E had higher hsCRP than AN-E. AN-E had lower mean hsCRP levels than healthy controls (HC+E and HC-E). IL-6 levels were higher in AN+E with elevated hsCRP (>3 mg/liter) than in AN+E with normal hsCRP levels. IGF-I was inversely associated with hsCRP in healthy women, suggesting a protective effect of GH on CV risk. However, this was not seen in AN. Few patients in any group had high-risk LDL or HDL levels.

CONCLUSIONS

Although hsCRP levels are lower in AN than healthy controls, OCP use puts such women at a greater than 20% chance of having hsCRP in the high-CV-risk (>3 mg/liter) category. The elevated mean IL-6 in women with AN and high-risk hsCRP levels suggests that increased systemic inflammation may underlie the hsCRP elevation in these patients. Although OCP use in AN was associated with slightly lower mean LDL and higher mean HDL, means were within the normal range, and few patients in any group had high-risk LDL or HDL levels. IGF-I levels appear to be important determinants of hsCRP in healthy young women. In contrast, IGF-I does not appear to mediate hsCRP levels in AN.

Middle-aged and Elderly Outpatients Show Lower Body Temperature Responses than the Young, Even with the Same C-reactive Protein Levels

The variation of body temperature response and C-reactive protein (CRP) levels with age was investigated. A cross-sectional study on new outpatients between January 2004 and June 2005 was carried out. Body temperature and serum CRP levels were examined for screening purposes in 1081 patients. Mean axillary body temperature was maintained at around 36.7°C in early adulthood, and gradually declined in middle age. Middle-aged and elderly outpatients tended to show a lower body temperature response than the young, even with the same CRP levels. The critical age (boundary age) was assumed to be when the relationship between body temperature response and CRP level changed. This study suggests that the boundary age is about 40 years old.

Relationship between markers of metabolic control and inflammation on severity of periodontal disease in patients with diabetes mellitus

AIM

The aim of this study was to investigate the relationship between markers of metabolic control and inflammation and periodontal disease parameters in patients with diabetes.

MATERIAL & METHODS

One hundred and eighty one adult patients with diabetes attending treatment at two diabetes centres were invited to participate in the study. Periodontal examination included full-mouth assessment for probing depths and bleeding on probing (BOP). Blood analyses were carried out for glycated haemoglobin, (HbA1c), high-sensitivity C reactive protein, (hsCRP) and lipid profile comprising total cholesterol, low-density lipoprotein cholesterol (LDL chol), high-density lipoprotein cholesterol (HDL chol) and triglycerides.

RESULTS

Upon multivariate analysis, periodontal disease severity in terms of increased percentage of BOP and mean percentage of sites with probing depths > or = 5 mm were found to be associated with inadequate glycaemic control as measured by HbA1c (p<0.01). HsCRP was also found to be a significant predictor for mean percentage of sites with probing depths > or = 5 mm (p<0.05). After controlling for age, gender, smoking habits and number of teeth, positive correlations were found between HbA1c and percentage sites with probing depths > or = 5 mm, percentage sites BOP, total cholesterol, LDL chol and triglycerides (p<0.05). Using the adjusted differences, subjects with acceptable glycaemic control (HbA1c < 8%) showed a lower percentage of sites with BOP and probing depths > or = 5 mm (p<0.05) when compared with those having inadequate glycaemic control. There was also a trend towards lower blood cholesterol in the well-controlled group.

CONCLUSION

The level of glycaemic control as measured by HbA1c emerged as the most consistent risk factor associated with the extent and severity of periodontal disease in this study cohort.

C-reactive protein genetics is associated with carotid artery compliance in men in The Cardiovascular Risk in Young Finns Study

Although C-reactive protein (CRP) is known to predict cardiovascular events, its status as a causal risk factor is still controversial. CRP gene single nucleotide polymorphisms (SNPs) have been shown to associate with CRP concentration, but no direct independent effect on early atherosclerotic changes has been demonstrated. We aimed to determine if CRP gene polymorphisms or haplotypes are associated with CRP concentration or carotid artery compliance (CAC), an indicator of subclinical atherosclerosis. We genotyped CRP gene polymorphisms -717A>G, -286C>T>A, +1059G>C, +1444C>T and +1846G>A and measured CRP concentration and CAC in 2283 young adults participating in The Cardiovascular Risk in Young Finns Study. A strong association was found between CRP genotypes and CRP concentration, which was also seen at the haplotype level. Linear regression analysis showed an independent effect of each SNP on CRP concentration after adjustment for risk factors, except for +1444 in males. Moreover, -286C>T>A, +1444C>T and +1846G>A were associated with CAC in males, but not in females. Men carrying the SNP -286 allele C had increased CAC after adjusting for risk factors. These data suggest that the presence of high producer CRP genotype is deleterious to carotid elasticity in men.

The relative influences of fitness and fatness on inflammatory factors

OBJECTIVE

Inflammatory processes contribute to disease pathways and may be affected by behavioral lifestyle factors. The relative contributions of fatness and cardiorespiratory fitness to inflammatory factors remain unclear. The present review examines the hypothesis that the association between fitness and inflammatory factors is independent of fatness.

METHODS

Data were examined from 40 observational studies on the association between fitness/physical activity and inflammatory factors after making statistical adjustment for measures of fatness, and from 12 randomized controlled trials that considered the impact of improved fitness and weight loss.

RESULTS

Two thirds of the observational studies report an inverse relationship between inflammatory factors and fitness after adjustment for fatness. Evidence from randomized controlled trials does not consistently support the hypothesis. Inconsistencies in the literature may be related to various factors such as age, gender, and disease status.

CONCLUSIONS

Both fitness and fatness appear to contribute to inflammatory factors, although it is unclear whether fatness is a mediator or if both fitness and fatness share the same causal pathways. Lifestyle interventions for primary prevention in the general public should therefore focus on both increasing physical activity and the prevention of excess adiposity, although the optimal exercise dose and body composition for preventing chronic inflammatory processes is not well established.