C-Reactive Protein Concentrations Are Very High and More Stable over Time Than the Traditional Vascular Risk Factors Total Cholesterol and Systolic Blood Pressure in an Australian Aboriginal Cohort

Antioxidant biomarkers and cardiometabolic risk markers in an Aboriginal community in remote Australia: a cross-sectional study

OBJECTIVE

High-quality diets, characterised by nutrient-rich foods, are one of the foundations for health and well-being. Indicators of diet quality, antioxidants, are associated with protection against cardiometabolic diseases. The current study explores relationships between plasma antioxidants and cardiometabolic risk among Aboriginal people in Australia.

DESIGN

As part of a community-driven health promotion programme, we conducted a cross-sectional study including a health-behaviour questionnaire, plasma antioxidants and cardiometabolic risk markers (anthropometric, blood pressure measurements, fasting glucose, glycated Hb (HbA1c), lipids, C-reactive protein and albumin-creatinine-ratio) continuous and categorised into population-specific cut-offs. Antioxidants (β-carotene, β-cryptoxanthin, lycopene, lutein-zeaxanthin, retinol and α-tocopherol measured using HPLC) were applied to a principal component analysis, which aggregated these into a single component. Linear regression models were applied to investigate associations between the antioxidant component and cardiometabolic risk markers.

SETTING

Community in a remote area in Northern Territory, Australia.

PARTICIPANTS

A total of 324 Aboriginal people, mean age 35·5 (range 15-75) years.

RESULTS

Antioxidant component levels were higher among individuals with higher self-reported vegetable intake (P < 0·01), higher among individuals with higher self-reported fruit intake (P = 0·05) and lower among current smokers (P = 0·06). Linear regression revealed an inverse association between the antioxidant component and C-reactive protein (β = -0·01, P < 0·01) after adjusting for confounders.

CONCLUSION

Higher plasma antioxidant levels, indicators of diet quality, were associated with lower levels of high-sensitivity C-reactive protein in this Aboriginal population in remote Australia. This association suggests plasma antioxidants may be protective against inflammation; however, longitudinal studies are needed to examine this potentially protective relationship.

High Levels of C-Reactive Protein Are Associated with an Increased Risk of Ovarian Cancer: Results from the Ovarian Cancer Cohort Consortium

Growing epidemiologic evidence supports chronic inflammation as a mechanism of ovarian carcinogenesis. An association between a circulating marker of inflammation, C-reactive protein (CRP), and ovarian cancer risk has been consistently observed, yet, potential heterogeneity of this association by tumor and patient characteristics has not been adequately explored. In this study, we pooled data from case-control studies nested within six cohorts in the Ovarian Cancer Cohort Consortium (OC3) to examine the association between CRP and epithelial ovarian cancer risk overall, by histologic subtype and by participant characteristics. CRP concentrations were measured from prediagnosis serum or plasma in 1,091 cases and 1,951 controls. Multivariable conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI). When CRP was evaluated using tertiles, no associations with ovarian cancer risk were observed. A 67% increased ovarian cancer risk was found for women with CRP concentrations >10 mg/L compared with <1 mg/L (OR = 1.67; 95% CI = 1.12-2.48). A CRP concentration >10 mg/L was positively associated with risk of mucinous (OR = 9.67; 95% CI = 1.10-84.80) and endometrioid carcinoma (OR = 3.41; 95% CI = 1.07-10.92), and suggestively positive, although not statistically significant, for serous (OR = 1.43; 95% CI = 0.82-2.49) and clear cell carcinoma (OR = 2.05; 95% CI = 0.36-11.57; P heterogeneity = 0.20). Heterogeneity was observed with oral contraceptive use (P interaction = 0.03), where the increased risk was present only among ever users (OR = 3.24; 95% CI = 1.62-6.47). This study adds to the existing evidence that CRP plays a role in ovarian carcinogenesis and suggests that inflammation may be particularly implicated in the etiology of endometrioid and mucinous carcinoma. SIGNIFICANCE: C-reactive protein is involved in ovarian carcinogenesis, and chronic inflammation may be particularly implicated in the etiology of mucinous and endometrioid carcinomas.

Depressogenic vulnerability and gender-specific patterns of neuro-immune dysregulation: What the ratio of cortisol to C-reactive protein can tell us about loss of normal regulatory control

We examined whether the ratio of cortisol (CORT) to high-sensitivity C-reactive protein (hsCRP), an index that captures the integrity of homeostatic regulation between the hypothalamic-pituitary-adrenal (HPA) axis and inflammatory processes, is associated with vulnerability to depression in a gender specific manner and whether glucocorticoid receptor (GR) sensitivity plays a role in these associations. Fasting blood samples were collected between 08:45 and 09:15 and assayed for CORT, hsCRP, and leukocyte count in 213 healthy, medication-free men and women. The NEO-Personality Inventory was used to assess neuroticism, extraversion and anxiety. We used the Hamilton Depression Interview to assess depressive symptoms, the Buss-Perry anger subscale to measure anger, and the Pittsburgh Sleep Quality Index to evaluate subjective sleep quality and its components. Log-transformed CORT/CRP values were analyzed using multiple regression with Holms' adjusted p-values and age, body mass index (BMI), and race as covariates. GR sensitivity was estimated using the log-transformed ratio of neutrophils (N)-to-monocytes (M). The log-transformed ratio of CORT/CRP did not differ between men and women but was significantly and negatively associated with age and BMI. Severity of depressive symptoms, extraversion, anxiety, and sleep quality were associated with the CORT/CRP ratio in a gender-specific manner. For women, decreasing CORT/CRP ratios, suggestive of an insufficient release of CORT coupled with a heightened inflammatory state, were associated with increasing severity of depressive symptoms, decreasing quality of sleep, increasing frequency of sleep disturbance, and decreasing extraversion. For men, increasing frequency of daytime disturbance and levels of anxiety were associated with increasing CORT/CRP ratio, suggestive of an enhanced release of CORT relative to attenuated levels of hsCRP. For both genders, increasing anger was associated with decreasing CORT/CRP ratios. Although results suggested GR downregulation in women but not men, such differences did not mediate the observed associations. With the use of the CORT/CRP ratio, we showed that vulnerability factors for depression are associated with a loss of normal regulatory controls resulting in gender-specific patterns of neuro-immune dysregulation. That GR downregulation did not influence these associations suggests that the loss of regulatory controls in at risk individuals is primarily at the level of the hormone. Beyond the individual contribution of each component of the CORT/CRP ratio, disruption of normal neuroimmune regulatory feedback provides a plausible biological framework useful in understanding biobehavioral vulnerabilities to depression in a gender specific manner. The CORT/CRP ratio may be a viable biomarker not only for delineating risk for MDD but also progression and treatment responses among patients with MDD; possibilities that are testable in future studies.

Effect of periodontal therapy on arterial structure and function among aboriginal australians: a randomized, controlled trial

Observational studies and nonrandomized trials support an association between periodontal disease and atherosclerotic vascular disease. Both diseases occur frequently in Aboriginal Australians. We hypothesized that nonsurgical periodontal therapy would improve measures of arterial function and structure that are subclinical indicators of atherosclerotic vascular disease. This parallel-group, randomized, open label clinical trial enrolled 273 Aboriginal Australians aged ≥18 years with periodontitis. Intervention participants received full-mouth periodontal scaling during a single visit, whereas controls received no treatment. Prespecified primary end points measured 12-month change in carotid intima-media thickness, an indicator of arterial structure, and 3- and 12-month change in pulse wave velocity, an indicator of arterial function. ANCOVA used complete case data to evaluate treatment group differences. End points could be calculated for 169 participants with follow-up data at 3 months and 168 participants at 12 months. Intima-media thickness decreased significantly after 12 months in the intervention group (mean reduction=-0.023 [95% confidence interval {CI}, -0.038 to -0.008] mm) but not in the control group (mean increase=0.002 [95% CI, -0.017 to 0.022] mm). The difference in intima-media thickness change between treatment groups was statistically significant (-0.026 [95% CI, -0.048 to -0.003] mm; P=0.03). In contrast, there were no significant differences between treatment groups in pulse wave velocity at 3 months (mean difference, 0.06 [95% CI, -0.17 to 0.29] m/s; P=0.594) or 12 months (mean difference, 0.21 [95% CI, -0.01 to 0.43] m/s; P=0.062). Periodontal therapy reduced subclinical arterial thickness but not function in Aboriginal Australians with periodontal disease, suggesting periodontal disease and atherosclerosis are significantly associated.

Evidence for low high-density lipoprotein cholesterol levels in Australian indigenous peoples: a systematic review

Background

Low plasma high-density lipoprotein cholesterol (HDL-C) levels are a strong, independent, but poorly understood risk factor for cardiovascular disease (CVD). Although this atherogenic lipid abnormality has been widely reported in Australia’s Indigenous peoples, Aboriginal and Torres Strait Islanders, the evidence has not come under systematic review. This review therefore examines published data for Indigenous Australians reporting 1) mean HDL-C levels for both sexes and 2) factors associated with low HDL-C.

Methods

PubMed, Medline and Informit ATSI Health databases were systematically searched between 1950 and 2012 for studies on Indigenous Australians reporting mean HDL-C levels in both sexes. Retrieved studies were evaluated by standard criteria. Low HDL-C was defined as: <1.0 mmol/L. Analyses of primary data associating measures of HDL-C with other CVD risk factors were also performed.

Results

Fifteen of 93 retrieved studies were identified for inclusion. These provided 58 mean HDL-C levels; 29 for each sex, most obtained in rural/regional (20%) or remote settings (60%) and including 51–1641 participants. For Australian Aborigines, mean HDL-C values ranged between 0.81-1.50 mmol/L in females and 0.76-1.60 mmol/L in males. Two of 15 studies reported HDL-C levels for Torres Strait Islander populations, mean HDL-C: 1.00 or 1.11 mmol/L for females and 1.01 or 1.13 mmol/L for males. Low HDL-C was observed only in rural/regional and remote settings - not in national or urban studies (n = 3) in either gender. Diabetes prevalence, mean/median waist-to-hip ratio and circulating C-reactive protein levels were negatively associated with HDL-C levels (all P < 0.05). Thirty-four per cent of studies reported lower mean HDL-C levels in females than in males.

Conclusions

Very low mean HDL-C levels are common in Australian Indigenous populations living in rural and remote communities. Inverse associations between HDL-C and central obesity, diabetes prevalence and inflammatory markers suggest a particularly adverse CVD risk factor profile. An absence of sex dichotomy in HDL-C levels warrants further investigation.

Relationship of high sensitivity C-reactive protein with presence and severity of coronary artery disease

Objective: Inflammation plays a key role in the pathogenesis of atherosclerosis. This study aimed to assess the relationship of serum inflammatory marker high sensitivity C Reactive protein (hsCRP), with the presence and severity of angiographically evaluated coronary artery disease (CAD).

Methods: This study was conducted at departments of physiology and cardiology, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh from August 2009 to March 2012. Eighty seven patients (57 males and 30 females) with angiographically evaluated CAD were studied. In all these patients CAD severity was assessed by Gensini scoring and vessel scoring. Control group consisted of 29 healthy subjects (17 males and 12 females). Fasting venous blood samples were analyzed for lipid profile and high sensitivity C-reactive protein (hsCRP).

Results: There were non-significant differences in age, weight and BMI among healthy subjects and CAD patients. Comparison of lipid profile between control and CAD patients showed that CAD patients had significantly higher TG and significantly lower HDL levels compared to control subjects. CAD patients presented with significantly higherhsCRP levels than controls. Linear regression analysis between hsCRP and CAD severity determined by Gensini scores showed a significant positive correlation (r=0.423, p=0.018). Triple vessel disease patients had significantly higher hsCRP levels than one vessel and two vessel disease, while the difference was non significant between one and two vessel disease groups.

Conclusions: These results suggest that patients with angiographically evaluated CAD have significantly higher levels of hsCRP levels compared to healthy individuals and are correlated with the presence & severity of CAD.

Combined use of high-sensitivity C-reactive protein and apolipoprotein B/apolipoprotein A-1 ratio prior to elective coronary angiography and oral glucose tolerance tests

OBJECTIVES

The study aimed to investigate the predictive value of the combination of high-sensitivity C-reactive protein (hs-CRP) and apolipoprotein B (apoB)/apoA-1 ratio for the outcomes of coronary angiography (CAG), echocardiography and oral glucose tolerance tests (OGTTs).

DESIGN AND METHODS

Hs-CRP, apoB, apoA-1, and the profiles of CAG, echocardiography and OGTTs as well as traditional risk factors were measured in 1757 cardiology patients.

RESULTS

Hs-CRP or apoB/apoA-1 ratio was significantly correlated with the presence and severity of angiographic profiles, the levels of left ventricular (LV) ejection fraction, LV mass and LV mass index, and the presence of abnormal glucose metabolism. The combination of hs-CRP and apoB/apoA-1 ratio had greater correlation with abnormal glucose metabolism than its individual components in patients with normal fasting glucose, and was an independent predictor for coronary artery disease.

CONCLUSIONS

The combination of hs-CRP and apoB/apoA-1 ratio may be a strong predictor for coronary artery disease and abnormal glucose metabolism.

Abdominal obesity and other risk factors largely explain the high CRP in indigenous Australians relative to the general population, but not gender differences: a cross-sectional study

Background

Previous studies reported high C-reactive protein (CRP) levels in Indigenous Australians, which may contribute to their high risk of cardiovascular disease. We compared CRP levels in Indigenous Australians and the general population, accounting for obesity and other risk factors.

Methods

Cross-sectional study of CRP and risk factors (weight, height, waist and hip circumferences, blood pressure, lipids, blood glucose, and smoking status) in population-based samples from the Diabetes and Related conditions in Urban Indigenous people in the Darwin region (DRUID) study, and the Australian Diabetes, Obesity and Lifestyle study (AusDiab) follow-up.

Results

CRP concentrations were higher in women than men and in DRUID than AusDiab. After multivariate adjustment, including waist circumference, the odds of high CRP (>3.0 mg/L) in DRUID relative to AusDiab were no longer statistically significant, but elevated CRP was still more likely in women than men. After adjusting for BMI (instead of waist circumference) the odds for elevated CRP in DRUID participants were still higher relative to AusDiab participants among women, but not men. Lower HDL cholesterol, impaired glucose tolerance (IGT), and higher diastolic blood pressure were associated with having a high CRP in both men and women, while current smoking was associated with high CRP in men but not women.

Conclusions

High concentrations of CRP in Indigenous participants were largely explained by other risk factors, in particular abdominal obesity. Irrespective of its independence as a risk factor, or its aetiological association with coronary heart disease (CHD), the high CRP levels in urban Indigenous women are likely to reflect increased vascular and metabolic risk. The significance of elevated CRP in Indigenous Australians should be investigated in future longitudinal studies.

A comparative study of biomarkers for risk prediction in acute coronary syndrome-Results of the SIESTA (Systemic Inflammation Evaluation in non-ST-elevation Acute coronary syndrome) study

OBJECTIVE

We compared the 1-year predictive value of several inflammatory and non-inflammatory biomarkers in ACS patients.

METHODS

In 610 patients (73.0% male)--36.0% unstable angina (UA) and 64.0% NSTEMI--we assessed high-sensitivity C-reactive protein (hs-CRP), interleukins 6, 10 and 18, soluble CD40 ligand, P- and E-selectin, NT-proBNP, fibrinogen and cystatin C at hospital admission. Two outcomes at 1-year follow up were selected for analysis: (1) all-cause death, MI, UA, or coronary revascularization, and (2) all-cause death, and non-fatal MI. The effect of biomarker levels on endpoints was examined by the Cox proportional hazards model, and their discrimination ability with the C statistic (AUC).

RESULTS

Of 549 patients (90.0%) who completed the 1-year follow up, 206 (37.5%) and 54 (8.9%) reached the first and second composite endpoints, respectively. None of the biomarkers studied improved prediction of the first endpoint. However, considered as continuous variables, and in combination, NT-proBNP and fibrinogen, increased the AUC from 0.64 (95% CI 0.55-0.72) to 0.73 (95% CI 0.64-0.81; p=0.02) for prediction of the second endpoint. Cut-off values for NT-proBNP and fibrinogen, regarding best sensitivity and specificity for prediction of the secondary endpoint were 1043.9 ng/L and 4.47 mg/dL, respectively. For these cut-off points, sensitivity, specificity, positive predictive value and negative predictive value were 40.5% vs 59.5%, 83.3% vs 67.1%, 18.8% vs 14.9% and 93.5% vs 94.4% for NT-proBNP and fibrinogen, respectively.

CONCLUSION

In ACS patients, inflammatory biomarkers offer modest incremental information to that provided by clinical risk markers. Fibrinogen and NT-proBNP measurements, however, improve cardiovascular risk prediction.

Intra-individual variation in serum C-reactive protein over 4 years: an implication for epidemiologic studies

BACKGROUND

Data on long-term intra-individual variability in high-sensitivity C-reactive protein (hsCRP) are needed to determine whether one measurement adequately reflects usual levels in prospective studies of on the etiology of cancer and other chronic diseases; when not reflective, the ability to statistically detect modest to moderate associations is reduced. The authors estimated the size of this source of variability and consequent attenuation of the relative risk (RR).

METHODS

High-sensitivity C-reactive protein (hsCRP) concentration was measured using a high-sensitivity immunoturbidometric assay in sera collected at years 2, 4, and 6 from 50 men in the placebo arm of the Prostate Cancer Prevention Trial (PCPT). After natural logarithm-transformation of hsCRP, analysis of variance was used to estimate the within- and between-individual variances from which the intra-class correlation coefficient (ICC) was calculated.

RESULTS

The observed RR due to an ICC < 1 was calculated by e((ln true RR*ICC)) for a range of true RRs. The 4-year ICC was 0.66. Measuring hsCRP once and assuming no other error, if the true RRs were 1.50, 2.00, and 3.00 when comparing high with low concentration, then the observed RRs would be 1.31, 1.58, and 2.06, respectively.

CONCLUSION

Investigators planning to measure hsCRP only once should design adequately sized studies to preserve inferences for hypothesized modest to moderate RRs.