Intraindividual variability of C-reactive protein: the Multi-Ethnic Study of Atherosclerosis

Association of Changes in C-Reactive Protein Level Trajectories Through Early Adulthood With Cognitive Function at Midlife: The CARDIA Study

BACKGROUND AND OBJECTIVES

Late-life inflammation has been linked to dementia risk and preclinical cognitive decline, but less is known about early adult inflammation and whether this could influence cognition in midlife. We aimed to identify inflammation levels through early adulthood and determine association of these trajectories with midlife cognition.

METHODS

We used data from the Coronary Artery Risk Development in Young Adults study to identify inflammation trajectories (C-reactive protein [CRP] level <10 mg/L) over 18 years through early adulthood (age range 24-58) in latent class analysis and to assess associations with cognition 5 years after the last CRP measurement (age range 47-63). Six cognitive domains were evaluated from tests of verbal memory, processing speed, executive function, verbal and category fluency, and global cognition; poor cognitive performance was defined as a decline of ≥1 SD less than the mean on each domain. The primary outcome was poor cognitive performance. Logistic regression was used to adjust for demographics, smoking, alcohol use, physical activity, and APOE 4 status.

RESULTS

Among 2,364 participants, the mean (SD) age was 50.2 (3.5) years; 55% were female, and 57% were White. Three CRP trajectories emerged over 18 years: lower stable (45%), moderate/increasing (16%), and consistently higher (39%). Compared with lower stable CRP, both consistently higher (adjusted odds ratio [aOR] 1.67, 95% CI 1.23-2.26) and moderately/increasing (aOR 2.04, 95% CI 1.40-2.96) CRP had higher odds of poor processing speed; consistently higher CRP additionally had higher odds of poor executive function (aOR 1.36, 95% CI 1.00-1.88). For memory (moderately/increasing aOR 1.36, 95% CI 1.00-1.88; consistently higher aOR 1.18, 95% CI 0.90-1.54), letter fluency (moderately/increasing aOR 1.00, 95% CI 0.69-1.43; consistently higher aOR 1.05, 95% CI 0.80-1.39), category fluency (moderately/increasing aOR 1.16, 95% CI 0.82-1.63; consistently higher aOR 1.11, 95% CI 0.85-1.45), or global cognition (moderately/increasing aOR 1.16, 95% CI 0.82-1.63; consistently higher aOR 1.11, 95% CI 0.85-1.45), no association was observed.

DISCUSSION

Consistently higher or moderate/increasing inflammation starting in early adulthood may lead to worse midlife executive function and processing speed. Study limitations include selection bias due to loss to follow-up and reliance on CRP as the only inflammatory marker. Inflammation is important for cognitive aging and may begin much earlier than previously known.

Effects of aerobic and resistance exercise for 9 months on serum free light chains in type 2 diabetes

Background and aims: Serum polyclonal free light chains (FLCs) levels are associated with overall survival in the general population, reflecting their utility as a biomarker of underlying immune activation and inflammation. Regular exercise is known to ameliorate low-grade inflammation in chronic diseases such as type 2 diabetes; however, the effects of different exercise training modalities on FLCs in adults with type 2 diabetes is unknown. This study investigated the effects of 9-month of aerobic, resistance or combined supervised exercise on serum FLCs in 164 patients with type 2 diabetes (age 58 ± 8 years; 63% female). Methods: 164 participants from the Health Benefits of Aerobic and Resistance Training in individuals with type 2 diabetes trial (HART-D) were randomly assigned to no exercise (n = 27), aerobic exercise alone (n = 41), resistance exercise alone (n = 49), or a combination of aerobic and resistance exercise (n = 47). Fasting serum samples were collected before and after completion of the intervention to quantify changes in kappa and lambda FLCs, and serum creatinine, using commercially-available ELISAs. Results: At baseline, combined kappa and lambda FLCs (FLC sum; calculated as kappa + lambda FLCs) were positively correlated with high-sensitive C-reactive protein (hs-CRP) (r = 0.237, p < 0.05) and fat mass (r = 0.162, p < 0.05), and negatively associated with aerobic fitness (r = -0.238, p < 0.05). While non-exercise controls exhibited an increase in FLCs over the 9-month study, exercise training blunted this increase (Δ FLC sum control arm: 3.25 ± 5.07 mg∙L-1 vs. all exercise arms: -0.252 ± 6.60 mg∙L-1, p < 0.05), regardless of exercise modality. Conclusion: Serum FLCs were associated with physical fitness and body composition in patients with type 2 diabetes. 9-month of exercise training prevented the accumulation of FLCs, regardless of exercise modality. Unlike hs-CRP-which did not change during the trial-serum FLCs may serve as a more sensitive biomarker of chronic low-grade inflammation in this population.

Dietary magnesium, C-reactive protein and interleukin-6: The Strong Heart Family Study

OBJECTIVES

To examine the associations of dietary Mg intake with inflammatory biomarkers (C-reactive protein (CRP) and interleukin 6 (IL-6)), and the interaction of dietary Mg intake with single nucleotide polymorphism (SNP) rs3740393, a SNP related to Mg metabolism and transport, on CRP and IL-6 among American Indians (AIs).

METHODS

This cross-sectional study included AI participants (n = 1,924) from the Strong Heart Family Study (SHFS). Mg intake from foods and dietary supplements was ascertained using a 119-item Block food frequency questionnaire, CRP and IL-6 were measured from blood, and SNP rs3740393 was genotyped using MetaboChip. Generalized estimating equations were used to examine associations of Mg intake, and the interaction between rs3740393 and dietary Mg, with CRP and IL-6.

RESULTS

Reported Mg intake was not associated with CRP or IL-6, irrespective of genotype. A significant interaction (p-interaction = 0.018) was observed between Mg intake and rs3740393 on IL-6. Among participants with the C/C genotype, for every 1 SD higher in log-Mg, log-IL-6 was 0.04 (95% CI: -0.10 to 0.17) pg/mL higher. Among participants with the C/G genotype, for every 1 SD higher in log-Mg, log-IL-6 was 0.08 (95% CI: -0.21 to 0.05) pg/mL lower, and among participants with the G/G genotype, for every 1 SD higher in log-Mg, log-IL-6 was 0.19 (95% CI: -0.38 to -0.01) pg/mL lower.

CONCLUSIONS

Mg intake may be associated with lower IL-6 with increasing dosage of the G allele at rs3740393. Future research is necessary to replicate this finding and examine other Mg-related genes that influence associations of Mg intake with inflammation.

GlycA as a Novel Biomarker of Systemic Inflammation in Hypothyroidism

Background: GlycA is a novel glycoprotein biomarker of systemic inflammation and cardiovascular risk. Our objective was to assess the levels of GlycA in individuals with hypothyroidism. We also explored whether levothyroxine (LT4)-treated patients had different levels of GlycA, with attention to thyrotropin (TSH) levels. Methods: We performed a cross-sectional analysis, using baseline data from the ELSA-Brasil cohort study. We included only participants with serum TSH and GlycA levels measurements, using magnetic resonance spectroscopy (n = 4745). We excluded individuals with endogenous hyperthyroidism and those using drugs impacting thyroid function. Participants not taking LT4 and whose serum TSH was 0.4-4.0 mIU/L were classified as euthyroid (EU) and those with elevated TSH as undiagnosed hypothyroidism (UH). For those on LT4 (n = 345), adequacy of treatment was defined as TSH within the reference range. Those with TSH <0.4 mIU/L were considered over-treated (OT), and those >4.0 mIU/L, under-treated (UT). Both (UT+OT) were considered inadequately treated (IT). Group comparisons were performed by Kruskal-Wallis, adjusted Chi-square, and the post hoc Dunn test. Additional subgroup analysis were performed in patients with circulating thyroperoxidase antibodies (TPO-Ab+). Respective multivariable analyses were performed to evaluate the relationship between thyroid-related variables and GlycA levels (Generalized Linear Model), as well as an abnormal GlycA (>400 μmol/L; Logistic Binary Regression). Results: The prevalence rate of UH was 9.8% (467/4745) and, among those on LT4, only 61.7% (213/345) were adequately treated (AT). GlycA levels were higher in IT in comparison to EU (429 vs. 410 μmol/L, p < 0.01) but did not differ between UH (413 μmol/L) and euthyroidism. However, the subgroup analysis of those TPO-Ab+ showed that not only those with IT, but also those with UH, had higher levels of GlycA in comparison to euthyroidism (423 and 424 vs. 402 μmol/L, p = 0.04). This association between higher levels of GlycA and IT was maintained even in multivariable analysis (odds ratio 1.53, confidence interval 1.03 to 2.31) Lower levels of GlycA were detected in AT (405 μmol/L,) compared with OT (432 μmol/L, 0.04) and UT (423 μmol/L, p = 0.02). Conclusions: Patients with IT, both OT and UT, had higher GlycA levels, which may be associated with low-grade systemic inflammation and, possibly, increased cardiovascular risk.

Particulate matter, traffic-related air pollutants, and circulating C-reactive protein levels: The Multiethnic Cohort Study

Inhaled particles and gases can harm health by promoting chronic inflammation in the body. Few studies have investigated the relationship between outdoor air pollution and inflammation by race and ethnicity, socioeconomic status, and lifestyle risk factors. We examined associations of particulate matter (PM) and other markers of traffic-related air pollution with circulating levels of C-reactive protein (CRP), a biomarker of systemic inflammation. CRP was measured from blood samples obtained in 1994-2016 from 7,860 California residents participating in the Multiethnic Cohort (MEC) Study. Exposure to PM (aerodynamic diameter ≤2.5 μm [PM2.5], ≤10 μm [PM10], and between 2.5 and 10 μm [PM10-2.5]), nitrogen oxides (NOx, including nitrogen dioxide [NO2]), carbon monoxide (CO), ground-level ozone (O3), and benzene averaged over one or twelve months before blood draw were estimated based on participants' addresses. Percent change in geometric mean CRP levels and 95% confidence intervals (CI) per standard concentration increase of each pollutant were estimated using multivariable generalized linear regression. Among 4,305 females (55%) and 3,555 males (45%) (mean age 68.1 [SD 7.5] years at blood draw), CRP levels increased with 12-month exposure to PM10 (11.0%, 95% CI: 4.2%, 18.2% per 10 μg/m3), PM10-2.5 (12.4%, 95% CI: 1.4%, 24.5% per 10 μg/m3), NOx (10.4%, 95% CI: 2.2%, 19.2% per 50 ppb), and benzene (2.9%, 95% CI: 1.1%, 4.6% per 1 ppb). In subgroup analyses, these associations were observed in Latino participants, those who lived in low socioeconomic neighborhoods, overweight or obese participants, and never or former smokers. No consistent patterns were found for 1-month pollutant exposures. This investigation identified associations of primarily traffic-related air pollutants, including PM, NOx, and benzene, with CRP in a multiethnic population. The diversity of the MEC across demographic, socioeconomic, and lifestyle factors allowed us to explore the generalizability of the effects of air pollution on inflammation across subgroups.

Immuno-epigenetic signature derived in saliva associates with the encephalopathy of prematurity and perinatal inflammatory disorders

BACKGROUND

Preterm birth is closely associated with a phenotype that includes brain dysmaturation and neurocognitive impairment, commonly termed Encephalopathy of Prematurity (EoP), of which systemic inflammation is considered a key driver. DNA methylation (DNAm) signatures of inflammation from peripheral blood associate with poor brain imaging outcomes in adult cohorts. However, the robustness of DNAm inflammatory scores in infancy, their relation to comorbidities of preterm birth characterised by inflammation, neonatal neuroimaging metrics of EoP, and saliva cross-tissue applicability are unknown.

METHODS

Using salivary DNAm from 258 neonates (n = 155 preterm, gestational age at birth 23.28 - 34.84 weeks, n = 103 term, gestational age at birth 37.00 - 42.14 weeks), we investigated the impact of a DNAm surrogate for C-reactive protein (DNAm CRP) on brain structure and other clinically defined inflammatory exposures. We assessed i) if DNAm CRP estimates varied between preterm infants at term equivalent age and term infants, ii) how DNAm CRP related to different types of inflammatory exposure (maternal, fetal and postnatal) and iii) whether elevated DNAm CRP associated with poorer measures of neonatal brain volume and white matter connectivity.

RESULTS

Higher DNAm CRP was linked to preterm status (-0.0107 ± 0.0008, compared with -0.0118 ± 0.0006 among term infants; p < 0.001), as well as perinatal inflammatory diseases, including histologic chorioamnionitis, sepsis, bronchopulmonary dysplasia, and necrotising enterocolitis (OR range |2.00 | to |4.71|, p < 0.01). Preterm infants with higher DNAm CRP scores had lower brain volume in deep grey matter, white matter, and hippocampi and amygdalae (β range |0.185| to |0.218|). No such associations were observed for term infants. Association magnitudes were largest for measures of white matter microstructure among preterms, where elevated epigenetic inflammation associated with poorer global measures of white matter integrity (β range |0.206| to |0.371|), independent of other confounding exposures.

CONCLUSIONS

Inflammatory-related DNAm captures the allostatic load of inflammatory burden in preterm infants. Such DNAm measures complement biological and clinical metrics when investigating the determinants of neurodevelopmental differences.

Temporal relationship between atherogenic dyslipidemia and inflammation and their joint cumulative effect on type 2 diabetes onset: a longitudinal cohort study

BACKGROUND

Concurrent atherogenic dyslipidemia and elevated inflammation are commonly observed in overt hyperglycemia and have long been proposed to contribute to diabetogenesis. However, the temporal relationship between them and the effect of their cumulative co-exposure on future incident type 2 diabetes (T2D) remains unclear.

METHODS

Longitudinal analysis of data on 52,224 participants from a real-world, prospective cohort study (Kailuan Study) was performed to address the temporal relationship between high-sensitivity C-reactive protein (hsCRP) and the atherogenic index of plasma (AIP, calculated as triglyceride/high-density lipoprotein) in an approximately 4-year exposure period (2006/2007 to 2010/2011). After excluding 8824 participants with known diabetes, 43,360 nondiabetic participants were included for further analysis of the T2D outcome. Cox regression models were used to examine the adjusted hazard ratios (aHRs) upon the cumulative hsCRP (CumCRP) and AIP (CumAIP) in the exposure period.

RESULTS

In temporal analysis, the adjusted standardized correlation coefficient (β1) of hsCRP_2006/2007 and AIP_2010/2011 was 0.0740 (95% CI, 0.0659 to 0.0820; P < 0.001), whereas the standardized correlation coefficient (β2) of AIP_2006/2007 and hsCRP_2010/2011 was - 0.0293 (95% CI, - 0.0385 to - 0.0201; P < 0.001), which was significantly less than β1 (P < 0.001). During a median follow-up of 7.9 years, 5,118 T2D cases occurred. Isolated exposure to CumAIP or CumCRP was dose-dependently associated with T2D risks, independent of traditional risk factors. Significant interactions were observed between the median CumAIP (- 0.0701) and CumCRP thresholds (1, 3 mg/L) (P = 0.0308). Compared to CumAIP < - 0.0701 and CumCRP < 1 mg/L, those in the same CumAIP stratum but with increasing CumCRP levels had an approximately 1.5-fold higher T2D risk; those in higher CumAIP stratum had significantly higher aHRs (95% CIs): 1.64 (1.45-1.86), 1.87 (1.68-2.09), and 2.04 (1.81-2.30), respectively, in the CumCRP < 1, 1 ≤ CumCRP < 3, CumCRP ≥ 3 mg/L strata. Additionally, the T2D risks in the co-exposure were more prominent in nonhypertensive, nondyslipidemic, nonprediabetic, or female participants.

CONCLUSIONS

These findings suggest a stronger association between elevated hsCRP and future AIP changes than vice versa and highlight the urgent need for combined assessment and management of chronic inflammation and atherogenic dyslipidemia in primary prevention, particularly for those with subclinical risks of T2D.

Proteína C reactiva y su progresión en el tiempo para la detección de las fugas anastomóticas

Introducción. Las fugas anastomóticas son una complicación común y crítica en cirugía gastrointestinal, por lo que su identificación y tratamiento temprano son necesarios para evitar resultados adversos. El uso convencional con un valor límite de la proteína C reactiva ha demostrado una utilidad limitada. El objetivo de este estudio fue determinar la utilidad de la medición seriada de la proteína C reactiva en la detección de fugas anastomóticas. Métodos. Revisión prospectiva de base de datos retrospectiva de pacientes sometidos a cirugía abdominal mayor con al menos una anastomosis intestinal. Se midió la proteína C reactiva al tercer y quinto día posoperatorio. Las complicaciones se categorizaron según la clasificación de Clavien-Dindo. La precisión diagnóstica fue evaluada por el área bajo la curva. Resultados. Se incluyeron 157 pacientes, el 52 % mujeres. La edad promedio fue de 63,7 años. El mayor número de cirugías correspondió a gastrectomía (36,3 %), resección anterior de recto (15,3 %) y hemicolectomía derecha (13,4 %). El 25,5 % tuvieron alguna complicación postoperatoria y el 32,5 % (n=13) presentaron fuga en la anastomosis. El aumento de la proteína C reactiva tuvo un área bajo la curva de 0,918 con un punto de corte de aumento en 1,3 mg/L, sensibilidad de 92,3 % (IC95% 78 – 100) y una especificidad de 92,4 % (IC95% 88 – 96). Conclusiones. El aumento de 1,3 mg/L en la proteína C reactiva entre el día de la cirugía y el quinto día fue un predictor preciso de fugas anastomóticas en pacientes con cirugía abdominal mayor.

Examining the role of systemic chronic inflammation in diet and sleep relationship

BACKGROUND

It is well known that systemic chronic inflammation (SCI), which can be modulated by diet, is associated with poor sleep outcomes. However, the role of SCI in diet health and sleep quality relationship has not been well established.

METHODS

Here, by using the UK Biobank data set, we assessed the association between markers of SCI (leukocyte, platelet, lymphocyte, neutrophil, and basophil counts; C-reactive protein levels and neutrophil to lymphocyte ratio (NLR)), habitual intake of food groups, diet health and sleep quality in 449,084 participants. We also formally tested the possibility that SCI might mediate the relationship between diet health and sleep quality.

RESULTS

Our results revealed (i) negative associations between SCI and food groups that are abundant in healthy diets (fruit, vegetable and oily and non-oily fish) and (ii) positive associations between SCI and food groups that are abundant in unhealthy diets (processed meat). Sleep quality was also negatively associated with platelet counts, CRP levels and NLR. Crucially, however, while platelet and neutrophil counts, CRP levels and NLR fully mediated the association between diet health and sleep quality, leukocyte, lymphocyte and basophil counts partially mediated the associations between diet health and sleep quality.

CONCLUSION

Reducing SCI via dietary interventions could be an effective primary and/or complementary strategy to increase sleep quality. Further interventional trials are warranted to (i) establish the strength of associations, preferably by using validated diet and sleep measures and (ii) examine longer term effects of anti-inflammatory diets on sleep-, diet- and inflammation-related health outcomes.

Within-person reproducibility of proteoforms related to inflammation and renal dysfunction

Protein biomarkers and microheterogeneity have attracted increasing attention in epidemiological and clinical research. Knowledge of within-person reproducibility over time is paramount to determine whether a single measurement accurately reflects an individual's long-term exposure. Yet, research investigating within-person reproducibility for proteoforms is limited. We investigated the reproducibility of the inflammatory markers C-reactive protein (CRP), serum amyloid A (SAA), and calprotectin (S100A8/9), and the renal function marker cystatin C (CnC) using a novel immuno-MALDI-TOF MS assay. Reproducibility, expressed as intraclass correlation coefficient (ICC), was calculated for 16 proteoforms using plasma samples of the Western Norway B Vitamin Intervention Trial (WENBIT) cohort collected 1-3 y apart from 295 stable angina pectoris (SAP) patients and 16 weeks apart from 38 subjects of the Intervention with Omega Fatty Acids in High-risk Patients with Hypertriglyceridemic Waist (OMEGA) trial with abdominal obesity but no other documented co-morbidities. ICCs for inflammatory markers were lower in WENBIT (CRP: 0.51, SAAt: 0.38, S100At: 0.31) compared to OMEGA subjects (CRP: 0.71, SAAt: 0.73, S100At: 0.48), while comparable for CnCt (WENBIT: 0.69, OMEGA: 0.67). Excluding SAP patients with elevated inflammation (CRP > 10 µg/ml) increased the ICC of SAAt to 0.55. Reduction of the time interval from 3 to 1 y in WENBIT group increased ICCs for all proteoforms. With a few exceptions ICCs did not differ between proteoforms of the same biomarker. ICCs were highest in OMEGA subjects with fair-to-good reproducibility for all markers. Reproducibility of SAA and S100A8/9 proteoforms in the WENBIT cohort was related to inflammation. This work will inform future clinical and epidemiological research which relies on single time point biomarker assessment to investigate inflammation and renal function.

Cardiovagal Function Measured by the Deep Breathing Test: Relationships With Coronary Atherosclerosis

Background

The cardiovagal function can be assessed by quantification of respiratory sinus arrhythmia (RSA) during a deep breathing test. However, population studies of RSA and coronary atherosclerosis are lacking. This population‐based study examined the relationship between RSA during deep breathing and coronary atherosclerosis, assessed by coronary artery calcium score (CACS).

Methods and Results

SCAPIS (Swedish Cardiopulmonary Bioimage Study) randomly invited men and women aged 50 to 64 years from the general population. CACS was obtained from computed tomography scanning, and deep breathing tests were performed in 4654 individuals. Expiration–inspiration differences (E‐Is) of heart rates were calculated, and reduced RSA was defined as E‐I in the lowest decile of the population. The relationship between reduced RSA and CACS (CACS≥100 or CACS≥300) was calculated using multivariable‐adjusted logistic regression. The proportion of CACS≥100 was 24% in the lowest decile of E‐I and 12% in individuals with E‐I above the lowest decile (P<0.001), and the proportion of CACS≥300 was 12% and 4.8%, respectively (P<0.001). The adjusted odds ratio (OR) for CACS≥100 was 1.42 (95% CI, 1.10–1.84) and the adjusted OR for CACS≥300 was 1.62 (95% CI, 1.15–2.28), when comparing the lowest E‐I decile with deciles 2 to 10. Adjusted ORs per 1 SD lower E‐I were 1.17 (P=0.001) for CACS≥100 and 1.28 (P=0.001) for CACS≥300.

Conclusions

Low RSA during deep breathing is associated with increased coronary atherosclerosis as assessed by CACS, independently of traditional cardiovascular risk factors. Cardiovagal dysfunction could be a prevalent and modifiable risk factor for coronary atherosclerosis in the general population.

DNA Methylation and Protein Markers of Chronic Inflammation and Their Associations With Brain and Cognitive Aging

BACKGROUND AND OBJECTIVES

To investigate chronic inflammation in relation to cognitive aging by comparison of an epigenetic and serum biomarker of C-reactive protein and their associations with neuroimaging and cognitive outcomes.

METHODS

At baseline, participants (n = 521) were cognitively normal, around 73 years of age (mean 72.4, SD 0.716), and had inflammation, vascular risk (cardiovascular disease history, hypertension, diabetes, smoking, alcohol consumption, body mass index), and neuroimaging (structural and diffusion MRI) data available. Baseline inflammatory status was quantified by a traditional measure of peripheral inflammation-serum C-reactive protein (CRP)-and an epigenetic measure (DNA methylation [DNAm] signature of CRP). Linear models were used to examine the inflammation-brain health associations; mediation analyses were performed to interrogate the relationship between chronic inflammation, brain structure, and cognitive functioning.

RESULTS

We demonstrate that DNAm CRP shows significantly (on average 6.4-fold) stronger associations with brain health outcomes than serum CRP. DNAm CRP is associated with total brain volume (β = -0.197, 95% confidence interval [CI] -0.28 to -0.12, p _FDR = 8.42 × 10^-6), gray matter volume (β = -0.200, 95% CI -0.28 to -0.12, p _FDR = 1.66 × 10^-5), and white matter volume (β = -0.150, 95% CI -0.23 to -0.07, p _FDR = 0.001) and regional brain atrophy. We also find that DNAm CRP has an inverse association with global and domain-specific (speed, visuospatial, and memory) cognitive functioning and that brain structure partially mediates this CRP-cognitive association (up to 29.7%), dependent on lifestyle and health factors.

DISCUSSION

These results support the hypothesis that chronic inflammation may contribute to neurodegenerative brain changes that underlie differences in cognitive ability in later life and highlight the potential of DNAm proxies for indexing chronic inflammatory status.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that a DNAm signature of CRP levels is more strongly associated with brain health outcomes than serum CRP levels.

Elevated IL-6 and CRP levels are associated with incident self-reported major mobility disability: A pooled analysis of older adults with slow gait speed

BACKGROUND

Elevated Interleukine-6 (IL-6) and C-reactive protein (CRP) are associated with aging-related reductions in physical function, but little is known about their independent and combined relationships with major mobility disability (MMD), defined as the self-reported inability to walk a quarter-mile.

METHODS

We estimated the absolute and relative effect of elevated baseline IL-6, CRP, and their combination on self-reported MMD risk among older adults (≥68 years; 59% female) with slow gait speed (<1.0m/s). Participants were MMD-free at baseline. IL-6 and CRP were assessed using a central laboratory. The study combined a cohort of community dwelling high-functioning older adults (Health ABC) with two trials of low-functioning adults at risk of MMD (LIFE-P, LIFE). Analyses utilized Poisson regression for absolute MMD incidence and proportional hazards models for relative risk.

RESULTS

We found higher MMD risk per unit increase in log IL-6 [HR=1.26 (95% CI 1.13 to 1.41)]. IL-6 meeting pre-determined threshold considered to be high (>2.5 pg/mL) was similarly associated with higher risk of MMD [HR=1.31 (95% CI: 1.12 to 1.54)]. Elevated CRP (CRP >3.0 mg/L) was also associated with increased MMD risk [HR=1.38 (95% CI: 1.10 to 1.74)]. The CRP effect was more pronounced among participants with elevated IL-6 [HR=1.62 (95% CI: 1.12 to 2.33)] compared to lower IL-6 levels [HR=1.19 (95% CI: 0.85 to 1.66)].

CONCLUSIONS

High baseline IL-6 and CRP were associated with increased risk of MMD among older adults with slow gait speed. A combined biomarker model suggests CRP was associated with MMD when IL-6 was elevated.

The Impact of hs-CRP on Cardiovascular Risk Stratification in Pilots and Air Traffic Controllers

INTRODUCTION: We assessed determinants of serum hs-CRP level in pilots and air traffic controllers (ATCs) and its impact on their atherosclerotic cardiovascular disease (ASCVD) risk.METHODS: We obtained serum hs-CRP measurements, evaluated traditional cardiovascular risk factors and assessed global ASCVD risk based on 2018 ESH/ESC guidelines. Elevated hs-CRP was hs-CRP values > 3 mg L¹. Determinants of elevated hs-CRP were assessed using stepwise logistic regression analysis. We used the net reclassification method to evaluate the impact of hs-CRP levels on global ASCVD risk.RESULTS: Of the 335 subjects (mean age 45.4 11.6 yr, 70% pilots, 99% men, 37% Caucasians), 127 individuals (39.5%) presented with elevated hs-CRP levels. Compared to those with normal hs-CRP, individuals with elevated hs-CRP were older with faster heart rate and higher blood pressure, BMI, and P wave amplitude. The proportion of individuals with elevated hs-CRP was greater among those with smoking habits, physical inactivity, MetS, tachycardia, altered P wave axis, LVH, and HT-TOD. Aging (aOR 2.15 [1.676.98]), hypertension (aOR 3.88 [2.296.58]), type 2 diabetes (aOR 6.71 [1.7710.49]), tachycardia (aOR 2.03 [1.914.53]), and LVH (aOR 2.13 [1.647.11]) were the main factors associated with elevated hs-CRP levels. Low, moderate, high, and very high risk were observed in 24 (15%), 68 (41%), 62 (37%), and 12 (7%) subjects, respectively. Including hs-CRP resulted in the net reclassification of 25% of subjects, mostly from moderate to high risk.CONCLUSION: The integration of hs-CRP improved the estimation of global ASCVD risk stratification. However, a survey with a comprehensive population assessing the cost/benefit impact of such a referral is needed.Buila NB, Ntambwe ML, Mupepe DM, Lubenga YN, Bantu J-MB, Mvunzi TS, Kabanda GK, Lepira FB, Kayembe PK, Ditu SM, MBuyamba-Kabangu J-R. The impact of hs-CRP on cardiovascular risk stratification in pilots and air traffic controllers. Aerosp Med Hum Perform. 2020; 91(11):886891.

GlycA Levels during the Earliest Stages of Rheumatoid Arthritis: Potential Use as a Biomarker of Subclinical Cardiovascular Disease

This study aimed at evaluating the clinical relevance of glycoprotein profiles during the earliest phases of rheumatoid arthritis (RA) as biomarkers of cardiovascular (CV) risk and treatment response. Then, GlycA and GlycB serum levels were measured using 1H-nuclear magnetic resonance in 82 early RA patients, 14 clinically-suspect arthralgia (CSA), and 28 controls. Serum glycosyltransferase activity was assessed by a colorimetric assay. Subclinical CV disease was assessed by Doppler-ultrasound. We found that GlycA and GlycB serum levels were increased in RA (both p < 0.001), but not in CSA, independently of cardiometabolic risk factors. Increased serum glycosyltransferase activity paralleled GlycA (r = 0.405, p < 0.001) and GlycB levels (r = 0.327, p = 0.005) in RA. GlycA, but not GlycB, was associated with atherosclerosis occurrence (p = 0.012) and severity (p = 0.001). Adding GlycA to the mSCORE improved the identification of patients with atherosclerosis over mSCORE alone, increasing sensitivity (29.7 vs. 68.0%) and accuracy (55.8 vs. 76.6%) and allowing reclassification into more appropriate risk categories. GlycA-reclassification identified patients with impaired lipoprotein metabolism. Finally, baseline GlycA levels predicted poor clinical response upon anti-rheumatic treatment at 6 and 12 months in univariate and multivariate analysis. In sum, increased GlycA levels during the earliest stage of RA can be considered a powerful biomarker for CV risk stratification and treatment response.

Reproducibility of novel immune-inflammatory biomarkers over 4 months: an analysis with repeated measures design

Aim: Assessment of the feasibility and reliability of immune-inflammatory biomarker measurements. Methods: The following biomarkers were assessed in 207 predominantly healthy participants at baseline and after 4 months: MMF, TGF-β, suPAR and clusterin. Results: Intraclass correlation coefficients (95% CIs) ranged from good for TGF-β (0.75 [95% CI: 0.33-0.90]) to excellent for MMF (0.81 [95% CI: 0.64-0.90]), clusterin (0.83 [95% CI: 0.78-0.87]) and suPAR (0.91 [95% CI: 0.88-0.93]). Measurement of TGF-β was challenged by the large number of values below the detection limit. Conclusion: Single measurements of suPAR, clusterin and MMF could serve as feasible and reliable biomarkers of immune-inflammatory pathways in biomedical research.

A clinical model for identifying an inflammatory phenotype in mood disorders

Increasingly, clinical research has found inflammatory correlates of psychiatric disorders, particularly mood symptomatology. Biological measures may provide greater precision in many cases and may capture clinically-relevant inflammatory signposts, such as central obesity risk, inflammation-associated co-morbid medical conditions, or proinflammatory lifestyle choices. In order to expand understanding of the role of inflammation in mood disorders, we propose a more inclusive clinical model for capturing an inflammatory phenotype of depression by identifying clinically-relevant inflammatory phenotypes grounded in biology. Our model includes chronic conditions and lifestyle behaviors associated with clinically elevated inflammation in mood disorders. Elements of this "inflamed depression" model include: obesity, low HDL concentrations, elevated triglyceride concentrations, chronically elevated blood pressure, clinical diagnosis of hypothyroidism, migraines, rheumatoid arthritis, adult onset diabetes, inflammatory bowel diseases, inflammatory skin conditions, and lifestyle factors including smoking cigarettes and chronic stress.

Usefulness of a Coronary Artery Disease Predictive Algorithm to Predict Global Risk for Cardiovascular Disease and Acute Coronary Syndrome

Traditional global risk assessment for cardiovascular disease fails to identify a significant percentage of the population initially classified at low or intermediate risk of cardiovascular disease that are actually at high risk for acute coronary syndrome (ACS). We examined a coronary artery disease predictive algorithm (CADPA) that includes 9 biomarkers involved in the pathogenesis of atherosclerosis initiated by endothelial damage and repair (hepatocyte growth factor, soluble FAS, Fas ligand, eotaxin, cutaneous T cell-attracting chemokine, monocyte chemotactic protein-3, interleukin-16, hemoglobin A1c, high-density lipoprotein-cholesterol), in addition to age, gender, diabetes, and family history of myocardial infarction that more accurately predicts 5-year risk of ACS to identify the patient population at discordantly high risk. We found that 34% of patients at low risk by global risk assessment and 72% of patients at intermediate risk by global risk assessment were actually at discordantly high risk for ACS. This patient population was disproportionately male and older in age. The biomarkers (per standard deviation) that most predicted the odds (95% confidence levels) of discordance were interleukin-16 (2.59 [2.21 to 3.03]), Fas Ligand (0.50 [0.43 to 0.57]), hepatocyte growth factor (1.72 [1.50 to 1.98]), soluble FAS (2.19 [1.86 to 2.58]), cutaneous T cell-attracting chemokine (0.46 [0.40 to 0.53]), and eotaxin (1.78 [1.56 to 2.03]), in addition to age, HbA1c, low-density lipoprotein-cholesterol, and glycated hemoglobin. In conclusion, although future prospective study validation is needed to establish a causal relation between CADPA and cardiovascular events, our study defines a patient population considered low to intermediate risk by conventional clinical evaluation, but who is at discordantly high risk indicated by the endothelial injury serum biomarker algorithm CADPA and may benefit from further evaluation and medical management.

Healthy lifestyles reduce suPAR and mortality in a Danish general population study

Background

The plasma level of the inflammatory biomarker soluble urokinase plasminogen activator receptor (suPAR) is a strong predictor of disease development and premature mortality in the general population. Unhealthy lifestyle habits such as smoking or unhealthy eating is known to elevate the suPAR level. We aimed to investigate whether change in lifestyle habits impact on the suPAR level, and whether the resultant levels are associated with mortality.

Results

Paired suPAR measurements from baseline- and the 5-year visit of the population-based Inter99 study were compared with the habits of diet, smoking, alcohol consumption, and physical activity. Paired suPAR measurements for 3225 individuals were analyzed by linear regression, adjusted for demographics and lifestyle habits. Compared to individuals with a healthy lifestyle, an unhealthy diet, low physical activity, and daily smoking were associated with a 5.9, 12.8, and 17.6% higher 5-year suPAR, respectively. During 6.1 years of follow-up after the 5-year visit, 1.6% of those with a low suPAR (mean 2.93 ng/ml) died compared with 3.8% of individuals with a high suPAR (mean 4.73 ng/ml), P <  0.001. In Cox regression analysis, adjusted for demographics and lifestyle, the hazard ratio for mortality per 5-year suPAR doubling was 2.03 (95% CI: 1.22-3.37).

Conclusion

Lifestyle has a considerable impact on suPAR levels; the combination of unhealthy habits was associated with 44% higher 5-year suPAR values and the 5-year suPAR was a strong predictor of mortality. We propose suPAR as a candidate biomarker for lifestyle changes as well as the subsequent risk of mortality.

Interleukin-10 as a predictor of major adverse cardiovascular events in a racially and ethnically diverse population: Multi-Ethnic Study of Atherosclerosis

PURPOSE

To understand if baseline levels of the anti-inflammatory cytokine interleukin-10 (IL-10) are associated with either subclinical atherosclerosis or risk for adverse cardiovascular (CV) events.

METHODS

The study included 930 adults from the Multi-Ethnic Study of Atherosclerosis (MESA) ancillary Stress Study. Participants, age 48-90 years at enrollment, were followed for an average of 10.2 years. IL-10 level was measured at the initial Stress Study visit. Cardiovascular outcomes were defined as composite CV death, myocardial infarction, stroke, stroke death, and resuscitated cardiac arrest. Coronary calcification was determined by Agatston coronary artery calcium (CAC) score. The association between IL-10 level and CV event risk was evaluated by Cox proportional hazard modeling, while that of IL-10 level and CAC presence and amount was determined with prevalence risk ratio (PRR) and linear regression modeling, respectively. Models were adjusted for CV risk factors and proinflammatory biomarkers.

RESULTS

After full adjustment, IL-10 level did not predict CV events (HR 1.19, 95%CI 0.89, 1.60) and was not associated with CAC prevalence (PRR 1.00, 95%CI 0.94, 1.07), nor amount of CAC in those with nonzero CAC (β -0.01, 95%CI -0.23, 0.21).

CONCLUSION

In individuals without clinical heart disease, baseline IL-10 level appears unrelated to risk of CV events and is a poor marker of subclinical coronary atherosclerosis.

Circulating Interleukin-6 is a biomarker for coronary atherosclerosis in nonalcoholic fatty liver disease: Results from the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Biomarkers to predict the presence and severity of subclinical cardiovascular disease (CVD) in nonalcoholic fatty liver disease (NAFLD) are lacking.

METHODS

3876 participants from the Multi-Ethnic Study of Atherosclerosis (MESA), without known chronic liver disease underwent baseline non-contrast cardiac CT, with NAFLD defined by validated liver:spleen ratio (L:S) < 1.0, and subclinical CVD defined by coronary artery calcium (CAC) score > 0. Randomly-selected subgroups underwent detailed inflammatory marker testing, including LpPLA2 mass (N = 2951), activity (N = 3020), high-sensitivity C-reactive protein (hsCRP; N = 3849), and interleukin-6 (IL-6; N = 3764). Among those with NAFLD, we estimated the prevalence of CAC > 0 and CAC > 100 for each SD biomarker increase, using multivariable log-binomial regression models adjusted for cardiometabolic risk factors.

RESULTS

Seventeen percent (N = 668) of participants met the criteria for NAFLD. NAFLD participants were younger (mean age 61 ± 10 vs. 63 ± 10 years, p < .0001) but more likely to have an elevated BMI (mean 31.1 ± 5.5 vs. 28.0 ± 5.2 kg/m2, p < .0001), diabetes (22% vs. 11%, p < .0001), and increased inflammatory biomarkers, including LpPLA2 activity, hsCRP and IL-6 (all p < .0001). Among NAFLD participants, IL-6 was the only biomarker independently associated with prevalent CAC > 0 (PR = 1.06 [1.00-1.11]), or CAC > 100 (PR = 1.09 [1.02-1.17]). In contrast, circulating LpPLA2 mass/activity and hsCRP were not associated with either the prevalence or severity of subclinical CVD (all p > .05).

CONCLUSION

In a large, multi-ethnic population with NAFLD, IL-6 is independently associated with the prevalence and severity of subclinical atherosclerosis. Further research into the longitudinal effects of NAFLD on progressive CVD will determine whether IL-6 is a marker or mediator of NAFLD-related atherosclerosis.

Variability in C-reactive protein is associated with cognitive impairment in women living with and without HIV: a longitudinal study

Despite the availability of effective antiretroviral therapies, cognitive impairment (CI) remains prevalent in HIV-infected (HIV+) individuals. Evidence from primarily cross-sectional studies, in predominantly male samples, implicates monocyte- and macrophage-driven inflammatory processes linked to HIV-associated CI. Thus, peripheral systemic inflammatory markers may be clinically useful biomarkers in tracking HIV-associated CI. Given sex differences in immune function, we focused here on whether mean and intra-individual variability in inflammatory marker-predicted CI in HIV+ and HIV- women. Seventy-two HIV+ (36 with CI) and 58 HIV- (29 with CI) propensity-matched women participating in the Women's Interagency HIV Study completed a neuropsychological battery once between 2009 and 2011, and performance was used to determine CI status. Analysis of 13 peripheral immune markers was conducted on stored biospecimens at three time points (7 and 3.5 years before neuropsychological data collection and concurrent with data collection). HIV+ women showed alterations in 8 immune markers compared to HIV- women. The strongest predictors of CI across HIV+ and HIV- women were lower mean soluble tumor necrosis factor receptor I (sTNFRI) levels, higher mean interleukin (IL)-6 levels, and greater variability in C-reactive protein (CRP) and matrix metalloproteinase (MMP)-9 (p values < 0.05). Stratified by HIV, the only significant predictor of CI was greater variability in CRP for both HIV+ and HIV- women (p values < 0.05). This variability predicted lower executive function, attention/working memory, and psychomotor speed in HIV+ but only learning in HIV- women (p values < 0.05). Intra-individual variability in CRP levels over time may be a good predictor of CI in predominately minority low-socioeconomic status midlife women.

Autonomic regulation of systemic inflammation in humans: A multi-center, blinded observational cohort study

OBJECTIVE

Experimental animal models demonstrate that autonomic activity regulates systemic inflammation. By contrast, human studies are limited in number and exclusively use heart rate variability (HRV) as an index of cardiac autonomic regulation. HRV measures are primarily dependent on, and need to be corrected for, heart rate. Thus, independent autonomic measures are required to confirm HRV-based findings. Here, the authors sought to replicate the findings of preceding HRV-based studies by using HRV-independent, exercise-evoked sympathetic and parasympathetic measures of cardiac autonomic regulation to examine the relationship between autonomic function and systemic inflammation.

METHODS

Sympathetic function was assessed by measuring heart rate changes during unloaded pedaling prior to onset of exercise, divided into quartiles; an anticipatory heart rate (AHRR) rise during this period is evoked by mental stress in many individuals. Parasympathetic function was assessed by heart rate recovery (HRR) 60s after finishing cardiopulmonary exercise testing, divided into quartiles. Parasympathetic dysfunction was defined by delayed heart rate recovery (HRR) ≤12.beats.min^-1, a threshold value associated with higher cardiovascular morbidity/mortality in the general population. Systemic inflammation was primarily assessed by neutrophil-lymphocyte ratio (NLR), where a ratio >4 is prognostic across several inflammatory diseases and correlates strongly with elevated plasma levels of pro-inflammatory cytokines. High-sensitivity C-reactive protein (hsCRP) was also measured.

RESULTS

In 1624 subjects (65±14y; 67.9% male), lower HRR (impaired vagal activity) was associated with progressively higher NLR (p=0.004 for trend across quartiles). Delayed HRR, recorded in 646/1624 (39.6%) subjects, was associated with neutrophil-lymphocyte ratio >4 (relative risk: 1.43 (95%CI: 1.18-1.74); P=0.0003). Similar results were found for hsCRP (p=0.045). By contrast, AHRR was not associated with NLR (relative risk: 1.24 (95%CI: 0.94-1.65); P=0.14).

CONCLUSIONS

Delayed HRR, a robust measure of parasympathetic dysfunction, is independently associated with leukocyte ratios indicative of systemic inflammation. These results further support a role for parasympathetic modulation of systemic inflammation in humans.

The Association of Mid- and Late-Life Systemic Inflammation with Brain Amyloid Deposition: The ARIC-PET Study

BACKGROUND

Although inflammation has been implicated in the pathogenesis of Alzheimer's disease, the effects of systemic inflammation on brain amyloid deposition remain unclear.

OBJECTIVE

We examined the association of midlife and late-life systemic inflammation with late-life brain amyloid levels in a community sample of non-demented older adults from the Atherosclerosis Risk in Communities (ARIC) - PET Study.

METHODS

339 non-demented participants (age: 75 [SD 5]) were recruited from the ARIC Study to undergo florbetapir PET (amyloid) imaging. Blood levels of high sensitivity C-reactive protein (CRP), a marker of systemic inflammation, were measured 22 years (Visit 2), 16 years (Visit 4), and up to 2 years before PET imaging (Visit 5). Elevated brain amyloid deposition (standardized uptake value ratio >1.2) was the primary outcome.

RESULTS

Our primary analyses found no association of midlife and late-life CRP with late-life brain amyloid levels. However, in secondary stratified analyses, we found that higher midlife (Visit 2) CRP was associated with elevated amyloid among males (OR 1.65, 95% CI: 1.13-2.42), and among white (OR 1.33, 95% CI: 1.02-1.75), but not African American, participants (p-interactions<0.05). Among male participants, those who maintained high CRP levels (≥3 mg/L) throughout mid- and late-life were most likely to have elevated brain amyloid (OR, 8.81; 95% CI: 1.23, 62.91).

CONCLUSIONS

Although our primary analysis does not support an association between systemic inflammation and brain amyloid deposition, we found evidence for sex- and race-dependent associations. However, findings from subgroup analyses should be interpreted with caution.

GlycA, a novel biomarker of systemic inflammation and cardiovascular disease risk

Background

GlycA is a novel spectroscopic marker of systemic inflammation with low intra-individual variability and other attributes favoring its clinical use in patients with chronic inflammatory and autoimmune diseases. GlycA is unique in its composite nature, reflecting both increased glycan complexity and circulating acute phase protein levels during local and systemic inflammation. Recent studies of GlycA from cross-sectional, observational and interventional studies have been highly informative, demonstrating that GlycA is elevated in acute and chronic inflammation, predicts death in healthy individuals and is associated with disease severity in patients with chronic inflammatory diseases such as rheumatoid arthritis, psoriasis and lupus. Moreover, following treatment with biological therapy in psoriasis, reduction in skin disease severity was accompanied by a decrease in GlycA levels and improvement in vascular inflammation.

Conclusions

Collectively, these findings suggest GlycA is a marker that tracks systemic inflammation and subclinical vascular inflammation. However, larger prospective studies and randomized trials are necessary in order to assess the impact of novel therapies on GlycA in patients with chronic inflammatory conditions, which may be concomitant with cardiovascular benefits.

Cumulative Exposure to High-Sensitivity C-Reactive Protein Predicts the Risk of Cardiovascular Disease

BACKGROUND

One measurement of hs-CRP (high-sensitivity C-reactive protein) is associated with increased risk of cardiovascular disease (CVD). The objective of this study was to characterize the association of cumulative exposure to increased hs-CRP with incident cardiovascular events.

METHODS AND RESULTS

We included 53 065 participants with hs-CRP measured at 3 examinations in 2006, 2008, and 2010. Cumulative exposure to hs-CRP was calculated as the weighted sum of the average hs-CRP level for each time interval (level×time). Participants were classified into nonexposed group (hs-CRP<3.0 mg/L in all 3 examinations), 1-exposed group (hs-CRP≥3.0 mg/L in 1 of the 3 examinations), 2-exposed group (hs-CRP≥3.0 mg/L in 2 of the 3 examinations), and 3-exposed group (hs-CRP≥3.0 mg/L in 3 examinations). Cox proportional hazards models were used to assess the association of cumulative hs-CRP with incident CVD. The study showed a dose-response pattern with risk of CVD and myocardial infarction as the number of years of exposure to hs-CRP increases. Participants in the 3-exposed group had significantly increased CVD risk with hazard ratio (95% confidence interval) of 1.38 (1.11-1.72), in comparison with 1.28 (1.07-1.52) for participants in the 2-exposed group and 1.13 (0.97-1.31) for those in the 1-exposed group (P<0.05); meanwhile, the similar and significant associations were also observed for myocardial infarction with respective hazard ratio (95% confidence interval) of 2.13 (1.42-3.18), 1.60 (1.12-2.27), and 1.57 (1.17-2.10). The associations between stroke and cumulative hs-CRP were not statistically significant (P=0.360).

CONCLUSIONS

Cumulative exposure to hs-CRP was dose dependently associated with a subsequent increased risk of CVD and myocardial infarction.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov/. Unique identifier: ChiCTR-TNC-11001489.

C-reactive protein levels are inversely correlated with the apolipoprotein B-48-containing triglyceride-rich lipoprotein production rate in insulin resistant men

The pro-inflammatory state and elevated plasma levels of post-prandial triglycerides (TG) are associated with increased cardiovascular disease risk. Recent studies suggested that the increase in the production rate of post-prandial lipoproteins observed in patients with insulin resistance (IR) may be caused, at least in part, by the dysregulation of intestinal insulin sensitivity triggered by inflammation.

OBJECTIVE

The objective of the present study was to evaluate the association between IR, plasma C-reactive protein (CRP) levels and the kinetics of TG-rich lipoprotein (TRL) containing apolipoprotein (apo) B-48 in a large sample of insulin sensitive (IS) and IR men.

METHODS

The in vivo kinetics of TRL apoB-48 were measured in 151 men following a primed-constant infusion of l-[5,5,5-D₃]leucine. IR subjects (n=91) were characterized by fasting TG levels ≥1.5mmol/L and an index of homeostasis model assessment of IR (HOMA-IR)≥2.5 or type 2 diabetes, while IS subjects (n=24) were characterized by an HOMA-IR index <2.5 and TG levels <1.5mmol/L.

RESULTS

IR subjects had higher TRL apoB-48 production rate (+202%; P<0.0001) and CRP levels (+51%; P=0.01) than IS subjects. TRL apoB-48 production rate and CRP levels were inversely correlated in IR subjects (r=-0.32; P=0.002). IR subjects with CRP levels above the median (2.20mg/L) had lower TRL apoB-48 production rate than IR subjects with CRP levels below the median (Δ=-24%; P<0.05).

CONCLUSION

Our results confirm that IR is associated with increased TRL apoB-48 secretion and suggest that a higher inflammatory status is associated with decreased TRL apoB-48 secretion among IR subjects.

Prognostic Value of C-Reactive Protein in Resistant Hypertension

BACKGROUND

C-reactive protein (CRP) is a biomarker of systemic low-grade inflammation and a cardiovascular risk predictor in several clinical conditions. However, its prognostic value has never been examined in patients with resistant hypertension.

METHODS

In a prospective study, 476 patients with resistant hypertension had CRP levels measured at baseline, together with other clinical laboratory variables, including ambulatory blood pressures (BPs). Primary end points were a composite of major fatal or nonfatal cardiovascular events, all-cause mortality, and cardiovascular mortality. Multiple Cox regression assessed the associations between CRP levels and end points.

RESULTS

Median CRP was 3.8mg/l (interquartile range: 2.0-7.2mg/l). After a median follow-up of 9 years, 103 major cardiovascular events occurred, and 120 patients died, 62 from cardiovascular causes. Patients with CRP levels above the median value had a doubled excess risk of major cardiovascular events (95% confidence interval: 1.29-3.06; P = 0.002) and an 86% higher risk of cardiovascular death (95% confidence interval: 1.07-3.25; P = 0.029), after adjustments for potential confounders including traditional cardiovascular risk factors and ambulatory BP and dipping pattern. A high CRP equally predicted coronary (hazard ratio: 2.04; 95% confidence interval: 1.10-3.76; P = 0.023) and cerebrovascular events (hazard ratio: 2.72; 95% confidence interval: 1.30-5.67; P = 0.007). In interaction and sensitivity analyses, CRP levels were stronger predictors of worse cardiovascular outcomes in younger and obese patients, and in those with uncontrolled ambulatory BPs and with the nondipping pattern.

CONCLUSIONS

In patients with resistant hypertension, elevated serum CRP levels is predictive of worse cardiovascular prognosis above and beyond other cardiovascular risk factors, including ambulatory BP levels and dipping patterns.

Inflammatory glycoproteins in cardiometabolic disorders, autoimmune diseases and cancer

The physiological function initially attributed to the oligosaccharide moieties or glycans on inflammatory glycoproteins was to improve protein stability. However, it is now clear that glycans play a prominent role in glycoprotein structure and function and in some cases contribute to disease states. In fact, glycan processing contributes to pathogenicity not only in autoimmune disorders but also in atherosclerotic cardiovascular disease, diabetes and malignancy. While most clinical laboratory tests measure circulating levels of inflammatory proteins, newly developed diagnostic and prognostic tests are harvesting the information that can be gleaned by measuring the amount or structure of the attached glycans, which may be unique to individuals as well as various diseases. As such, these newer glycan-based tests may provide future means for more personalized approaches to patient stratification and improved patient care. Here we will discuss recent progress in high-throughput laboratory methods for glycomics (i.e. the study of glycan structures) and glycoprotein quantification by methods such as mass spectrometry and nuclear magnetic resonance spectroscopy. We will also review the clinical utility of glycoprotein and glycan measurements in the prediction of common low-grade inflammatory disorders including cardiovascular disease, diabetes and cancer, as well as for monitoring autoimmune disease activity.

High-Sensitivity C-Reactive Protein and Cardiovascular Disease Across Countries and Ethnicities

Despite substantial differences in ethnicities, habits, cultures, the prevalence of traditional cardiovascular risk factors and affordable therapies, atherosclerosis remains the major cause of death in developing and developed countries. However, irrespective of these differences, inflammation is currently recognized as the common pathway for the major complications of atherosclerosis, stroke, and ischemic heart disease. A PubMed search was conducted for "high-sensitivity C-reactive protein" (hs-CRP) in combination with the terms race, ethnicity, gender, prevalence, geographic, epidemiology, cardiovascular, obesity, diabetes, hypertension, cholesterol, smoking, ischemic heart disease, stroke, and mortality. This review includes the articles that pertained to the topic and additional articles identified from the reference lists of relevant publications. This review describes the marked differences in cardiovascular mortality across countries and ethnicities, which may be attributed to inequalities in the prevalence of the classic risk factors and the stage of cardiovascular epidemiological transition. However, hs-CRP appears to contribute to the prognostic information regarding cardiovascular risk and mortality even after multiple adjustments. Considering the perception of cardiovascular disease as an inflammatory disease, the more widespread use of hs-CRP appears to represent a valid tool to identify people at risk, independent of their ancestry or geographic region. In conclusion, this review reports that the complications associated with vulnerable atherosclerotic plaques are triggered by the major mechanisms of dyslipidemia and inflammation; whereas both mechanisms are influenced by classic risk factors, hs-CRP contributes additional information regarding cardiovascular events and mortality.

A critical review of perfluorooctanoate and perfluorooctanesulfonate exposure and immunological health conditions in humans

Whether perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS), two widely used and biopersistent synthetic chemicals, are immunotoxic in humans is unclear. Accordingly, this article systematically and critically reviews the epidemiologic evidence on the association between exposure to PFOA and PFOS and various immune-related health conditions in humans. Twenty-four epidemiologic studies have reported associations of PFOA and/or PFOS with immune-related health conditions, including ten studies of immune biomarker levels or gene expression patterns, ten studies of atopic or allergic disorders, five studies of infectious diseases, four studies of vaccine responses, and five studies of chronic inflammatory or autoimmune conditions (with several studies evaluating multiple endpoints). Asthma, the most commonly studied condition, was evaluated in seven studies. With few, often methodologically limited studies of any particular health condition, generally inconsistent results, and an inability to exclude confounding, bias, or chance as an explanation for observed associations, the available epidemiologic evidence is insufficient to reach a conclusion about a causal relationship between exposure to PFOA and PFOS and any immune-related health condition in humans. When interpreting such studies, an immunodeficiency should not be presumed to exist when there is no evidence of a clinical abnormality. Large, prospective studies with repeated exposure assessment in independent populations are needed to confirm some suggestive associations with certain endpoints.

Cardiovascular Imaging for the Primary Prevention of Atherosclerotic Cardiovascular Disease Events

Traditional cardiovascular risk factors have well-known limitations for the accurate assessment of individual cardiovascular risk. Unlike risk factor-based scores which rely on probabilistic calculations derived from population-based studies, coronary artery calcium (CAC) scoring, and carotid ultrasound allow for the direct visualization and quantification of subclinical atherosclerosis with the potential for a more accurate, personalized risk assessment and treatment approach. Among strategies used to guide preventive management, CAC scoring has consistently and convincingly outperformed traditional risk factors for the prediction of adverse cardiovascular events. Moreover, several studies have demonstrated the potential of CAC testing to improve precision for the use of more intensive pharmacologic therapies, such as aspirin and statins, in patients most likely to derive benefit, as compared to atherosclerotic cardiovascular disease risk calculators. By comparison to CAC, the role of carotid ultrasound for the measurement of carotid intima-media thickness (CIMT) remains less well-elucidated but may be significantly improved with the inclusion of plaque screening and novel three-dimensional measurements of plaque volume and morphology. Despite significant evidence supporting the ability of non-invasive atherosclerosis imaging (particularly CAC) to guide preventive management, imaging remains an under-utilized strategy among current guidelines and clinical practice. Herein, we review evidence regarding CAC and carotid ultrasound for patient risk classification, with a comparison of these techniques to currently advocated traditional risk factor-based scores.

Six-year change in high-sensitivity C-reactive protein and risk of diabetes, cardiovascular disease, and mortality

BACKGROUND

Single measurements of elevated high-sensitivity C-reactive protein (hs-CRP) are associated with increased risk of diabetes, cardiovascular disease, and mortality. Large increases or sustained elevations in hs-CRP may be associated with even greater risk of these outcomes. The objective of this study was to characterize the association of 6-year change in hs-CRP with incident diabetes, incident cardiovascular events (heart disease, stroke, and heart failure), and mortality.

METHODS

We included 10,160 ARIC participants with hs-CRP measured at visits 2 (1990-1992) and 4 (1996-1998). Change in hs-CRP was categorized as sustained low/moderate (<3 mg/L at both visits), decreased (≥3 mg/L at visit 2 and <3 mg/L at visit 4), increased (<3 mg/L at visit 2 and ≥3 mg/L at visit 4), and sustained elevated (≥3 mg/L at both visits). Cox proportional hazards models were used to assess the association of 6-year change in hs-CRP with incident diabetes, cardiovascular events, and death during ~15 years after visit 4.

RESULTS

Compared with persons with sustained low/moderate hs-CRP, those with increased or sustained elevated hs-CRP had an increased risk of incident diabetes (hazard ratios [95% CIs] 1.56 [1.38-1.76] and 1.39 [1.25-1.56], respectively), whereas those with deceased hs-CRP did not. Persons with sustained elevated hs-CRP had an increased risk of coronary heart disease, ischemic stroke, heart failure, and mortality (hazard ratios [95% CIs] 1.51 [1.23-1.85], 1.70 [1.32-2.20], 1.60 [1.35-1.89], and 1.52 [1.37-1.69], respectively) compared with those with sustained low/moderate hs-CRP. Associations for sustained elevated hs-CRP were greater than for those with increased hs-CRP over 6 years.

CONCLUSIONS

Large increases or sustained elevations in hs-CRP over a 6-year period were associated with a subsequent increased risk of diabetes, and persons with sustained elevations in hs-CRP were at the highest risk for cardiovascular disease and mortality. Two measurements of hs-CRP are better than one for characterizing risk, and large increases are particularly prognostic.

Trajectories of peripheral interleukin-6, structure of the hippocampus, and cognitive impairment over 14 years in older adults

We aimed to investigate if trajectory components (baseline level, slope, and variability) of peripheral interleukin-6 (IL-6) over time were related to cognitive impairment and smaller hippocampal volume and if hippocampal volume explained the associations between IL-6 and cognitive impairment. Multivariable regression models were used to test the association between IL-6 trajectory components with change in neuroimaging measures of the hippocampus and with cognitive impairment among 135 older adults (70-79 years at baseline) from the Healthy Brain Project over 14 years. IL-6 variability was positively associated with cognitive impairment (odds ratio [OR] = 5.86, 95% confidence interval [CI]: 1.24, 27.61) and with greater decrease per year of gray matter volume of the hippocampus (β = -0.008, standard error = 0.004, p = 0.03). After adjustment for hippocampal volume, the OR of cognitive impairment decreased for each unit of IL-6 variability and CIs widened (OR = 4.36, 95% CI: 0.67, 28.29). Neither baseline levels nor slopes of IL-6 were related to cognitive impairment or hippocampal volume. We believe this has potential clinical and public health implications by suggesting adults with stable levels of peripheral IL-6 may be better targets for intervention studies for slowing or preventing cognitive decline.

Utility of a novel inflammatory marker, GlycA, for assessment of rheumatoid arthritis disease activity and coronary atherosclerosis

Introduction

GlycA is a novel inflammatory biomarker measured using nuclear magnetic resonance (NMR). Its NMR signal primarily represents glycosylated acute phase proteins. GlycA was associated with inflammation and development of cardiovascular disease in initially healthy women. We hypothesized that GlycA is a biomarker of disease activity and is associated with coronary artery atherosclerosis in patients with rheumatoid arthritis (RA).

Methods

We conducted a cross-sectional study of 166 patients with RA and 90 control subjects. GlycA was measured from an NMR signal originating from N-acetylglucosamine residues on circulating glycoproteins. The relationship between GlycA and RA disease activity (Disease Activity Score based on 28 joints (DAS28)) and coronary artery calcium score was determined.

Results

GlycA concentrations were higher in patients with RA (median (interquartile range): 398 μmol/L (348 to 473 μmol/L)) than control subjects (344 μmol/L (314 to 403 μmol/L) (P < 0.001). In RA, GlycA was strongly correlated with DAS28 based on erythrocyte sedimentation rate (DAS28-ESR) and DAS28 based on C-reactive protein (DAS28-CRP) and their components, including tender and swollen joint counts, global health score, ESR and CRP (all P < 0.001). The area under the receiver operating characteristic curve for GlycA’s ability to differentiate between patients with low versus moderate to high disease activity based on DAS28-CRP was 0.75 (95 % confidence interval (CI): 0.68, 0.83). For each quartile increase in GlycA, the odds of having coronary artery calcium increased by 48 % (95 % CI: 4 %, 111 %), independent of age, race and sex (P = 0.03).

Conclusion

GlycA is a novel inflammatory marker that may be useful for assessment of disease activity and is associated with coronary artery atherosclerosis in patients with RA.

GlycA: A Composite Nuclear Magnetic Resonance Biomarker of Systemic Inflammation

BACKGROUND

Nuclear magnetic resonance (NMR) spectra of serum obtained under quantitative conditions for lipoprotein particle analyses contain additional signals that could potentially serve as useful clinical biomarkers. One of these signals that we named GlycA originates from a subset of glycan N-acetylglucosamine residues on enzymatically glycosylated acute-phase proteins. We hypothesized that the amplitude of the GlycA signal might provide a unique and convenient measure of systemic inflammation.

METHODS

We developed a spectral deconvolution algorithm to quantify GlycA signal amplitudes from automated NMR LipoProfile® test spectra and assessed analytic precision and biological variability. Spectra of acute-phase glycoproteins and serum fractions were analyzed to probe the origins of the GlycA signal. GlycA concentrations obtained from archived NMR LipoProfile spectra of baseline plasma from 5537 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) were used to assess associations with demographic and laboratory parameters including measures of inflammation.

RESULTS

Major acute-phase protein contributors to the serum GlycA signal are α1-acid glycoprotein, haptoglobin, α1-antitrypsin, α1-antichymotrypsin, and transferrin. GlycA concentrations were correlated with high-sensitivity C-reactive protein (hsCRP) (r = 0.56), fibrinogen (r = 0.46), and interleukin-6 (IL-6) (r = 0.35) (all P &lt; 0.0001). Analytic imprecision was low (intra- and interassay CVs 1.9% and 2.6%, respectively) and intraindividual variability, assessed weekly for 5 weeks in 23 healthy volunteers, was 4.3%, lower than for hsCRP (29.2%), cholesterol (5.7%), and triglycerides (18.0%).

CONCLUSIONS

GlycA is a unique inflammatory biomarker with analytic and clinical attributes that may complement or provide advantages over existing clinical markers of systemic inflammation.

Association between Inflammation and Cardiac Geometry in Chronic Kidney Disease: Findings from the CRIC Study

Background

Left ventricular hypertrophy (LVH) and myocardial contractile dysfunction are independent predictors of mortality in patients with chronic kidney disease (CKD). The association between inflammatory biomarkers and cardiac geometry has not yet been studied in a large cohort of CKD patients with a wide range of kidney function.

Methods

Plasma levels of interleukin (IL)-1β, IL-1 receptor antagonist (IL-1RA), IL-6, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, high-sensitivity C-Reactive protein (hs-CRP), fibrinogen and serum albumin were measured in 3,939 Chronic Renal Insufficiency Cohort study participants. Echocardiography was performed according to the recommendations of the American Society of Echocardiography and interpreted at a centralized core laboratory.

Results

LVH, systolic dysfunction and diastolic dysfunction were present in 52.3%, 11.8% and 76.3% of the study subjects, respectively. In logistic regression analysis adjusted for age, sex, race/ethnicity, diabetic status, current smoking status, systolic blood pressure, urinary albumin- creatinine ratio and estimated glomerular filtration rate, hs-CRP (OR 1.26 [95% CI 1.16, 1.37], p<0.001), IL-1RA (1.23 [1.13, 1.34], p<0.0001), IL-6 (1.25 [1.14, 1.36], p<0.001) and TNF-α (1.14 [1.04, 1.25], p = 0.004) were associated with LVH. The odds for systolic dysfunction were greater for subjects with elevated levels of hs-CRP (1.32 [1.18, 1.48], p<0.001) and IL-6 (1.34 [1.21, 1.49], p<0.001). Only hs-CRP was associated with diastolic dysfunction (1.14 [1.04, 1.26], p = 0.005).

Conclusion

In patients with CKD, elevated plasma levels of hs-CRP and IL-6 are associated with LVH and systolic dysfunction.

Three-month variation of plasma pentraxin 3 compared with C-reactive protein, albumin and homocysteine levels in haemodialysis patients

Background

Inflammatory markers vary considerably over time in haemodialysis (HD) patients, yet the variability is poorly defined. The aim of the study was to assess changes of plasma levels of pentraxin-3 (PTX-3), C-reactive protein (CRP), albumin and homocysteine (Hcy) over 3 months and the association between the changes in these biomarkers and mortality.

Methods

In 188 prevalent HD patients, inflammatory markers were measured at inclusion and after 3 months. Mortality was recorded during a median follow-up of 41 months. The changes of the biomarker levels were categorized according to change in tertile for the specific biomarker. The variation was calculated as the intra-class correlation (ICC). Mortality was analysed by Kaplan–Meier and Cox proportional hazards model. The predictive strength was calculated for single measurements and for the variation of each inflammatory marker.

Results

The intra-individual variation (low ICC) was largest for PTX-3 [ICC 0.44; 95% confidence interval (CI): 0.33–0.55], albumin (ICC 0.58; 95% CI: 0.49–0.67) and CRP (ICC 0.59; 95% CI: 0.51–0.68) and lowest for Hcy (ICC 0.81; 95% CI: 0.77–0.86). During follow-up, 88 patients died.

Conclusions

PTX-3 measurements are less stable and show higher variation within patients than CRP, albumin and Hcy. Persistently elevated PTX-3 levels are associated with high mortality. Moreover, in multivariate logistic regression we found that stable high PTX-3 adds to the mortality risk, even after inclusion of clinical factors and the three other biomarkers. The associations of decreasing albumin levels as well as low Hcy levels with worse outcome reflect protein-energy wasting.

The association of nonalcoholic fatty liver disease, obesity, and metabolic syndrome, with systemic inflammation and subclinical atherosclerosis: the Multi-Ethnic Study of Atherosclerosis (MESA)

INTRODUCTION

We characterized the association of 3 metabolic conditions - obesity, metabolic syndrome, and nonalcoholic fatty liver disease (NAFLD) - with increased inflammation and subclinical atherosclerosis.

METHODS

We conducted cross-sectional analysis of 3976 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) with adequate CT imaging to diagnose NAFLD. Obesity was defined as BMI ≥ 30 kg/m(2), metabolic syndrome by AHA/NHLBI criteria, and NAFLD using non-contrast cardiac CT and a liver/spleen attenuation ratio (L/S) < 1. Increased inflammation was defined as high sensitivity C-reactive protein (hsCRP) ≥2 mg/L and subclinical atherosclerosis as coronary artery calcium (CAC) > 0. We studied the association of a stepwise increase in number of these metabolic conditions (0-3) with increased inflammation and CAC, stratifying results by gender and ethnicity.

RESULTS

Mean age of participants was 63 (±10) years, 45% were male, 37% white, 10% Chinese, 30% African American, and 23% were Hispanic. Adjusting for obesity, metabolic syndrome and traditional risk factors, NAFLD was associated with a prevalence odds ratio for hsCRP ≥2 mg/L and CAC >0 of 1.47 (1.20-1.79) and 1.37 (1.11-1.68) respectively. There was a positive interaction between female gender and NAFLD in the association with hsCRP ≥2 mg/L (p = 0.006), with no interaction by race. With increasing number of metabolic conditions, there was a graded increase in prevalence odds ratios of hsCRP ≥2 mg/L and CAC >0.

CONCLUSION

NAFLD is associated with increased inflammation and CAC independent of traditional risk factors, obesity and metabolic syndrome. There is a graded association between obesity, metabolic syndrome, and NAFLD with inflammation and CAC.

Trajectories of inflammatory markers and cognitive decline over 10 years

We aimed to examine trajectories of inflammatory markers and cognitive decline over 10 years. Cox proportional hazards models were used to examine the association between interleukin-6 and C-reactive protein (CRP) trajectory components (slope, variability, and baseline level) and cognitive decline among 1323 adults, aged 70-79 years in the Health, Aging, and Body Composition Study. We tested for interactions by sex and apolipoprotein E (APOE) genotype. In models adjusted for multiple covariates and comorbidities, extreme CRP variability was significantly associated with cognitive decline (hazard ratio [HR] 1.6, 95% confidence interval [CI]: 1.1-2.3). This association was modified by sex and APOE e4 (p < 0.001 for both), such that the association remained among women (HR = 1.8; 95% CI: 1.1, 3.0) and among those with no APOE e4 allele (HR = 1.6; 95% CI: 1.1, 2.5). There were no significant associations between slope or baseline level of CRP and cognitive decline nor between interleukin-6 and cognitive decline. We believe CRP variability likely reflects poor control of or greater changes in vascular or metabolic disease over time, which in turn is associated with cognitive decline.

Intraindividual variability over time in plasma biomarkers of inflammation and effects of long-term storage

PURPOSE

Systemic measures of chronic inflammation, often based on a single blood draw, are frequently used to study the associations between inflammation and chronic diseases such as cancer. However, more information is needed on the measurement error in these markers due to laboratory error, within-person variation over time, and long-term storage.

METHODS

We investigated the intraindividual variability of inflammation markers C-reactive protein (CRP), interleukin-6 (IL-6), and soluble tumor necrosis factor receptors I and II (sTNFRI and II) in a subsample of the Seattle Barrett's esophagus study cohort. Two fasting blood samples were collected between 1995 and 2009 from 360 participants on average 1.8 years apart. CRP, IL-6, and sTNF receptor levels were measured by immunonephelometry, ELISA, and multiplex assays, respectively. Intra- and inter-batch coefficients of variation (CV) were estimated using blinded pooled samples within each batch. Intraclass correlations (ICCs) were computed using random effects ANOVA.

RESULTS

Intra- and inter-batch CVs for the pooled plasma aliquots were low (2.4-8.9 %), suggesting little laboratory variability. Reliability over time was excellent for sTNF receptors (ICCsTNF-RI = 0.89, ICCsTNF-RII = 0.85) and fair-to-good for CRP and IL-6 (ICCCRP = 0.55, ICCIL-6 = 0.57). For samples stored for over 13 years, the ICCs for CRP and IL-6 were decreased but those for sTNF receptors were unaffected.

CONCLUSION

sTNF receptor levels are more stable within person over time than CRP or IL-6. Long-term storage of samples appears to increase the variability of CRP and IL-6 measures, while the reliability of soluble TNF receptor measures was not affected by storage time.

C-reactive protein is independently associated with coronary atherosclerosis burden among octogenarians

AIM OF THE STUDY

In contrast to the general population, individuals with primarily persistent elevation of inflammatory activity display a significant association between inflammatory biomarkers and atherosclerotic burden. In older individuals, immunosenescence upregulates the innate response and, by this way, may hypothetically favor the presence of this association. The aim of this study was to evaluate this hypothesis in healthy octogenarians.

METHODS

Participants (n = 208) aged 80 years or older, asymptomatic and without medical and laboratory evidence of chronic diseases or use of anti-inflammatory treatments were included in the study. Lipid profile and plasma C-reactive protein (CRP) were measured at baseline and cardiac computed tomography was performed within 1-week interval for measuring coronary calcium score (CCS).

RESULTS

The median plasma CRP was 1.9 mg/L (1.0–3.4) and 33 % of the participants had elevated CRP defined as C3 mg/L. Among those with high CRP, there was an increased frequency of high CCS (C100) as compared with their counterparts (71 vs 50 %, p = 0.001). The association between CRP and CCS persisted even after adjustment for age, sex, cardiovascular risk factors and statin therapy. The area under the receiver-operating curve for CRP was 0.606 using CCS C100 as a binary outcome. The sensitivities for CCS C100 were 40 and 74 % for the cutoff points of CRP C3 or 1 mg/L, respectively.

CONCLUSION

The present study was able to confirm that in very elderly individuals, systemic inflammatory activity is independently associated with coronary atherosclerosis burden.

Discordance between non-HDL-cholesterol and LDL-particle measurements: results from the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Cardiovascular risk assessment incorporates measurement of atherogenic lipids such as non-HDL cholesterol (non-HDL-C). It remains uncertain under which circumstances atherogenic lipoprotein enumeration such as LDL particle number (LDL-P) differs from simultaneously acquired non-HDL-C.

METHODS

Participants of the Multi-Ethnic Study of Atherosclerosis (MESA) were deemed LDL-P > non-HDL-C discordant if they exhibited higher LDL-P than expected for simultaneously measured non-HDL-C, given the observed distribution of both in MESA. Conversely, a lower LDL-P than would be suggested from non-HDL-C characterized LDL-P < non-HDL-C discordance. Regression models were used to estimate associations of demographics and comorbidities with discordance and of LDL-P and non-HDL-C with carotid intima-media thickness (CIMT) and detectable coronary artery calcium (CAC) among discordance groups.

RESULTS

Discordance was observed among 44% of subjects. LDL-P > non-HDL-C compared to LDL-P < non-HDL-C discordance was more common among Hispanics and smokers; among subjects with lower HDL-C, lower triglycerides, or greater insulin resistance by homeostatic model assessment of insulin resistance (HOMA-IR); and among subjects on lipid-lowering therapy, anti-hypertensive therapy, or hormone replacement therapy. In the setting of discordance, LDL-P exhibited a modestly greater association with CIMT than did non-HDL-C (+0.024-0.025 mm vs +0.018-0.021 mm per SD increase). In the presence of LDL-P < non-HDL-C discordance, LDL-P demonstrated a modestly greater association with detectable CAC than did non-HDL-C (OR 1.51 vs 1.46 per SD increase).

CONCLUSIONS

Our results demonstrated that disagreement between LDL-P and non-HDL-C was common and significantly associated with several clinical characteristics. In the setting of discordance, LDL-P was more closely associated with CIMT and CAC than non-HDL-C, though observed differences were small.

High-sensitivity C-reactive protein and cardiovascular disease: a resolute belief or an elusive link?

The role of inflammation in the propagation of atherosclerosis and susceptibility to cardiovascular (CV) events is well established. Of the wide array of inflammatory biomarkers that have been studied, high-sensitivity C-reactive protein (hsCRP) has received the most attention for its use in screening and risk reclassification and as a predictor of clinical response to statin therapy. Although CRP is involved in the immunologic process that triggers vascular remodeling and plaque deposition and is associated with increased CV disease (CVD) risk, definitive randomized evidence for its role as a causative factor in atherothrombosis is lacking. Whether measurement of hsCRP levels provides consistent, clinically meaningful incremental predictive value in risk prediction and reclassification beyond conventional factors remains debated. Despite publication of guidelines on the use of hsCRP in CVD risk prediction by several leading professional organizations, there is a lack of clear consensus regarding the optimal clinical use of hsCRP. This article reviews 4 distinct points from the literature to better understand the current state and application of hsCRP in clinical practice: 1) the biology of hsCRP and its role in atherosclerosis; 2) the epidemiological association of hsCRP with CVD; 3) the quality of hsCRP as a biomarker of risk; and 4) the use of hsCRP as a tool to initiate or tailor statin therapy. Furthermore, we highlight recommendations from societies and important considerations when using hsCRP to guide treatment decisions in the primary prevention setting.

Adipocytokines, hepatic and inflammatory biomarkers and incidence of type 2 diabetes. the CoLaus study

CONTEXT

There is contradictory information regarding the prognostic importance of adipocytokines, hepatic and inflammatory biomarkers on the incidence of type 2 diabetes. The objective was to assess the prognostic relevance of adipocytokine and inflammatory markers (C-reactive protein - CRP; interleukin-1beta - IL-1β; interleukin-6- IL-6; tumour necrosis factor-α - TNF-α; leptin and adiponectin) and gamma-glutamyl transpeptidase (γGT) on the incidence of type 2 diabetes.

METHODS

Prospective, population-based study including 3,842 non-diabetic participants (43.3% men, age range 35 to 75 years), followed for an average of 5.5 years (2003-2008). The endpoint was the occurrence of type 2 diabetes.

RESULTS

208 participants (5.4%, 66 women) developed type 2 diabetes during follow-up. On univariate analysis, participants who developed type 2 diabetes had significantly higher baseline levels of IL-6, CRP, leptin and γGT, and lower levels of adiponectin than participants who remained free of type 2 diabetes. After adjusting for a validated type 2 diabetes risk score, only the associations with adiponectin: Odds Ratio and (95% confidence interval): 0.97 (0.64-1.47), 0.84 (0.55-1.30) and 0.64 (0.40-1.03) for the second, third and forth gender-specific quartiles respectively, remained significant (P-value for trend = 0.05). Adding each marker to a validated type 2 diabetes risk score (including age, family history of type 2 diabetes, height, waist circumference, resting heart rate, presence of hypertension, HDL cholesterol, triglycerides, fasting glucose and serum uric acid) did not improve the area under the ROC or the net reclassification index; similar findings were obtained when the markers were combined, when the markers were used as continuous (log-transformed) variables or when gender-specific quartiles were used.

CONCLUSION

Decreased adiponectin levels are associated with an increased risk for incident type 2 diabetes, but they seem to add little information regarding the risk of developing type 2 diabetes to a validated risk score.