Relationship between insulin resistance and C-reactive protein in a patient population treated with second generation antipsychotic medications

Emerging Protein Biomarkers for the Diagnosis or Prediction of Gestational Diabetes-A Scoping Review

Introduction: Gestational diabetes (GDM), defined as hyperglycemia with onset or initial recognition during pregnancy, has a rising prevalence paralleling the rise in type 2 diabetes (T2DM) and obesity. GDM is associated with short-term and long-term consequences for both mother and child. Therefore, it is crucial we efficiently identify all cases and initiate early treatment, reducing fetal exposure to hyperglycemia and reducing GDM-related adverse pregnancy outcomes. For this reason, GDM screening is recommended as part of routine pregnancy care. The current screening method, the oral glucose tolerance test (OGTT), is a lengthy, cumbersome and inconvenient test with poor reproducibility. Newer biomarkers that do not necessitate a fasting sample are needed for the prompt diagnosis of GDM. The aim of this scoping review is to highlight and describe emerging protein biomarkers that fulfill these requirements for the diagnosis of GDM. Materials and Methods: This scoping review was conducted according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for scoping reviews using Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing & Allied Health Literature (CINAHL), PubMed, Embase and Web of Science with a double screening and extraction process. The search included all articles published in the literature to July 2020. Results: Of the 3519 original database citations identified, 385 were eligible for full-text review. Of these, 332 (86.2%) were included in the scoping review providing a total of 589 biomarkers studied in relation to GDM diagnosis. Given the high number of biomarkers identified, three post hoc criteria were introduced to reduce the items set for discussion: we chose only protein biomarkers with at least five citations in the articles identified by our search and published in the years 2017-2020. When applied, these criteria identified a total of 15 biomarkers, which went forward for review and discussion. Conclusions: This review details protein biomarkers that have been studied to find a suitable test for GDM diagnosis with the potential to replace the OGTT used in current GDM screening protocols. Ongoing research efforts will continue to identify more accurate and practical biomarkers to take GDM screening and diagnosis into the 21st century.

C-reactive protein and cardiovascular risk in bipolar disorder patients: A systematic review

OBJECTIVES

New research is revealing a strong association between inflammatory markers with bipolar disorder (BD), potentially due to the high prevalence of cardiovascular disease and cardiovascular risk factors in BD. We aimed to synthesize the literature examining the association between the clinically most relevant inflammatory marker, C-reactive protein (CRP) and cardiovascular disease and cardiovascular risk factors in patients with BD.

METHODS

MEDLINE, Embase and PsychInfo were systematically searched for all relevant English language articles published prior to April 2017. Articles were included if they examined the association between CRP and cardiovascular risk factors/disease in BD.

RESULTS

Fifteen relevant articles were retrieved. Studies were mostly cross-sectional and heterogeneous in the cardiovascular risk factors investigated. Overall, elevated CRP was associated with increased risk of metabolic syndrome, elevated body mass index, higher waist circumference, and obesity. CRP was inconsistently associated with elevated fasting glucose, insulin levels, serum triglycerides, total cholesterol levels, and low high density lipoprotein (HDL) levels. Atypical antipsychotic use may mediate some of these effects. No study examined CRP's association with actual cardiovascular disease (e.g. coronary artery disease) in BD.

CONCLUSIONS

In BD, CRP is associated with increases in several cardiovascular risk factors, suggesting that systemic inflammation could be a shared driving force for both outcomes of BD and cardiovascular risk. Further longitudinal research is needed in this area to verify causality, including an examination of actual cardiovascular disease. Non-pharmacological and pharmacological treatments with anti-inflammatory effects should also be investigated, particularly in patients with increased CRP, for their potential to reduce cardiovascular risk in BD.

Dietary intake and cardiometabolic biomarkers in relation to insulin resistance and hypertension in a middle-aged and elderly population in Beijing, China

This study investigated the relationships of dietary intake and cardiometabolic biomarkers with insulin resistance and hypertension in rural middle-aged and elderly people in China. One hundred and eight middle-aged and elderly adults were recruited in Zhangfang village in May 2014. We measured blood pressure, anthropometric parameters, and biochemical indexes, including high-sensitivity C-reactive protein (hsCRP), soluble intercellular adhesion molecule-1 (sICAM-1), glucose, insulin, and blood lipids. Homeostasis model assessment of insulin resistance index (HOMA-IR) was assessed on the basis of fasting glucose and insulin. We recorded participant demographic characteristics, dietary intake, and lifestyle using questionnaires. Hypertensive participants had higher levels of triglycerides (TG), hsCRP, sICAM-1, body fat percentage (BF%), arm muscle circumference (AMC) and HOMA-IR than nonhypertensive individuals. Hypertensive participants had higher carbohydrate intake but lower intakes of protein and fat. Carbohydrate intake was positively correlated with hsCRP, sICAM-1, TG, BF%, and HOMA-IR, and was negatively correlated with AMC. Protein and fat intakes were negatively correlated with hsCRP and sICAM-1. Protein intake was also significantly negatively correlated with TG and HOMA-IR, and positively correlated with AMC. HOMA-IR was positively correlated with hsCRP, sICAM-1, TG and BF%, and negatively correlated with AMC. Multivariable linear regression indicated that TG, sICAM-1, and hsCRP were significantly associated with HOMA-IR. In conclusion, in a rural Chinese population, high intake of carbohydrate and low intake of fat and protein were associated with insulin resistance and hypertension, possibly by increasing inflammatory factors such as sICAM-1 and hsCRP, increasing BF% and increasing the level of plasma TG.

C-reactive protein levels in schizophrenia: a review and meta-analysis

There is an impression in the literature that schizophrenia is associated with increased inflammation, including abnormal blood levels of the acute phase reactant C-reactive protein (CRP). We performed a meta-analysis of blood CRP levels to estimate the overall effect size, as well as a pooled analysis of the prevalence of an elevated CRP level in patients with schizophrenia and related disorders. We identified articles by searching PubMed, PsycInfo, and ISI, and the reference lists of identified studies. Eight studies met the inclusion criteria for the meta-analysis, and five studies were included in the pooled analysis. CRP levels were significantly increased in patients compared to controls (effect size=0.45, 95% confidence interval 0.34-0.55, p<0.001). There was a 28% prevalence of an elevated CRP level in patients with schizophrenia and related disorders. Our results support a growing body of literature that schizophrenia is associated with increased inflammation, although many studies did not control for potential confounding factors such as BMI and smoking. Given the high prevalence of elevated CRP, metabolic syndrome, and premature cardiovascular mortality, our findings also suggest that measurement of blood CRP levels may be germane to the clinical care of patients with schizophrenia and related disorders.

Acute-phase proteins in relation to neuropsychiatric symptoms and use of psychotropic medication in Huntington's disease

Activation of the innate immune system has been postulated in the pathogenesis of Huntington's disease (HD). We studied serum concentrations of C-reactive protein (CRP) and low albumin as positive and negative acute-phase proteins in HD. Multivariate linear and logistic regression was used to study the association between acute-phase protein levels in relation to clinical, neuropsychiatric, cognitive, and psychotropic use characteristics in a cohort consisting of 122 HD mutation carriers and 42 controls at first biomarker measurement, and 85 HD mutation carriers and 32 controls at second biomarker measurement. Significant associations were found between acute-phase protein levels and Total Functioning Capacity (TFC) score, severity of apathy, cognitive impairment, and the use of antipsychotics. Interestingly, all significant results with neuropsychiatric symptoms disappeared after additional adjusting for antipsychotic use. High sensitivity CRP levels were highest and albumin levels were lowest in mutation carriers who continuously used antipsychotics during follow-up versus those that had never used antipsychotics (mean difference for CRP 1.4 SE mg/L; P=0.04; mean difference for albumin 3 SE g/L; P<0.001). The associations found between acute-phase proteins and TFC score, apathy, and cognitive impairment could mainly be attributed to the use of antipsychotics. This study provides evidence that HD mutation carriers who use antipsychotics are prone to develop an acute-phase response.

Cardiovascular risk factors during second generation antipsychotic treatment are associated with increased C-reactive protein

OBJECTIVE

Severe mental disorder and cardiovascular disease (CVD) are often associated, and inflammation is implicated in both disorders. We investigated whether there is a relationship between CVD risk factors and inflammation in schizophrenia or bipolar disorder, and if second generation antipsychotics (SGA) interact.

METHODS

We included 361 patients in a naturalistic cross-sectional study, 235 subjects on current SGA treatment and 126 subjects not treated with SGA as controls. Cardiovascular parameters were measured and current medication recorded. Fasting plasma levels of the following cytokines were measured: high sensitivity CRP (hsCRP), soluble tumor necrosis factor receptor 1 (sTNF-R1), osteoprotegerin (OPG), soluble CD40 ligand (sCD40L), interleukin-1 receptor antagonist (IL-1Ra), von Willebrand factor (vWf) and interleukin-6 (IL-6).

RESULTS

In this relatively young sample of patients with a mean age of 33.3years, the following CVD risk factors were associated with elevated inflammation markers after adjusting for confounders: BMI, triglycerides and glucose with hsCRP (p=0.041-0.001), HDL-cholesterol and triglycerides with sTNF-R1 (p=0.009-0.001) and triglycerides with vWf (p=0.004). In patients treated with SGA, elevated hsCRP was significantly associated with high BMI (p=0.012), and with high glucose levels (p=0.003).

CONCLUSION

Several CVD risk factors are associated with elevated levels of inflammation markers in young patients with severe mental illness. The interaction between SGA and CVD risk factors on hsCRP levels might indicate a specific inflammatory activation related to SGA induced overweight and hyperglycemia. This suggests that hsCRP could be a valuable marker for future cardiovascular events, particularly in patients treated with SGA.

Sensitive and rapid quantification of C-reactive protein using quantum dot-labeled microplate immunoassay

Background

High-sensitivity C-reactive protein (hs-CRP) assay is of great clinical importance in predicting risks associated with coronary heart disease. Existing hs-CRP assays either require complex operation or have low throughput and cannot be routinely implemented in rural settings due to limited laboratory resources.

Methods

We developed a novel hs-CRP assay capable of simultaneously quantifying over 90 clinical samples by using quantum dots-labeled immunoassay within a standard 96-well microplate. The specificity of the assay was enhanced by adopting two monoclonal antibodies (mAbs) that target distinct hs-CRP epitopes, serving as the coating antibody and the detection antibody, respectively. In the presence of hs-CRP antigen, the fluorescence intensity of the mAb-Ag-mAb sandwich complex captured on the microplate can be read out using a microplate reader.

Results

The proposed hs-CRP assay provides a wide analytical range of 0.001-100 mg/L with a detection limit of 0.06 (0.19) μg/L within 1.5 h. The accuracy of the proposed assay has been confirmed for low coefficient of variations (CVs), 2.27% (intra-assay) and 8.52% (inter-assay), together with recoveries of 96.7-104.2%. Bland-Altman plots of 104 clinical samples exhibited good consistency among the proposed assay, commercial high-sensitivity ELISA, and nephelometry, indicating the prospects of the newly developed hs-CRP assay as an alternative to existing hs-CRP assays.

Conclusion

The developed assay meets the needs of the rapid, sensitive and high-throughput determination of hs-CRP levels within a short time using minimal resources. In addition, the developed assay can also be used to detect and quantify other diagnostic biomarkers by immobilizing specific monoclonal antibodies.