Determinants of raised C-reactive protein concentration in type 1 diabetes

Serum IL-17A concentration and a IL17RA single nucleotide polymorphism contribute to the risk of autoimmune type 1 diabetes

AIMS

Interleukin (IL)-17 is associated with autoimmunity. This study aimed to affirm the role of IL-17A, IL-17F and single nucleotide polymorphisms (SNPs) in genes related to them and their receptors in autoimmune type 1 diabetes (T1D) for Chinese population.

METHODS

In this study, 130 patients with autoimmune T1D and 140 non-T1D controls were included for analysis. Clinical and biochemical data were collected, and serum levels of IL-17A, IL-17F, IL-6, and high-sensitivity C reactive protein were measured using ELISA. The SNPs rs2275913, rs8193036, rs3819025, rs763780, rs879577, rs4819554, and rs708567 were genotyped using the SNaPshot assay.

RESULTS

IL-17A levels were higher in patients with autoimmune T1D than in controls (median [IQR] 28.83[37.38] vs. 16.68[8.10], p < 0.001) and high IL-17A was a risk factor for autoimmune T1D (odds ratio (OR), 1.013; 95% CI, 1.003-1.023; p = 0.013) after adjusting for confounding factors. Linear regression analysis revealed that log₁₀ IL-17A levels were independently associated with fasting C-peptide, IL-6, body mass index, and IL-17F. However, no independent association was found between IL-17F and autoimmune T1D. The GG genotype of SNP rs4819554 in the interleukin 17 receptor A (IL17RA) gene was associated with a decreased risk of autoimmune T1D (OR, 0.458; 95% CI, 0.246-0.852; p = 0.014) after adjusting for other confounders. The IL17RA rs4819554 GG genotype was negatively correlated with serum glutamic acid decarboxylase antibody appearance (p < 0.05).

CONCLUSIONS

Increased serum IL-17A, but not IL-17F, is a risk factor for autoimmune T1D. The GG genotype of IL17RA rs4819554 might decrease the risk for autoimmune T1D.

Inflammatory and cardiovascular diseases biomarkers in chronic hepatitis C virus infection: A review

Hepatitis C virus (HCV) infects 180 million people worldwide and over 4 million people in the United States. HCV infection is a major cause of chronic liver disease and is recognized as a risk factor for clinical cardiovascular disease (CVD). Many studies have shown increased prevalence of cardiac and inflammatory biomarkers in patients with chronic HCV infection (CHC), and though these markers may be used to risk stratify people for cardiac disease in the general population their role in the HCV population is unknown. Patients with CHC have elevated cardiac and inflammatory biomarkers compared to noninfected controls which may play a role in CVD risk stratification. We undertook a systematic review of inflammatory and cardiac biomarkers in people with HCV infection with a focus on the effect of CHC on serum levels of these markers and their utility as predictors of CVD in this population. Medline, EMBASE, and Cochrane databases were searched for relevant articles until June 2019. A total of 2430 results were reviewed with 115 studies included. Our review revealed that HCV infection significantly alters serum levels of markers of inflammation, endothelial function, and cardiac dysfunction prior to HCV treatment, and some of which may change in response to HCV therapy. Current risk stratification tools for development of CVD in the general population may not account for the increased inflammatory markers that appear to be elevated among HCV‐infected patients contributing to increased CVD risk.

Biomarkers of inflammation and endothelial dysfunction as predictors of pulse pressure and incident hypertension in type 1 diabetes: a 20 year life-course study in an inception cohort

AIMS/HYPOTHESIS

Vascular inflammation and endothelial dysfunction are thought to contribute to arterial stiffening and hypertension. This study aims to test this hypothesis with longitudinal data in the context of type 1 diabetes.

METHODS

We investigated, in an inception cohort of 277 individuals with type 1 diabetes, the course, tracking and temporal inter-relationships of BP, specifically pulse pressure (a marker of arterial stiffening) and hypertension, and the following biomarkers of systemic and vascular inflammation/endothelial dysfunction: C-reactive protein (CRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular cellular adhesion molecule-1 (sVCAM-1) and soluble E-selectin (sE-selectin). These biomarkers and other risk factors were measured at baseline and repeatedly up to 20 years after the onset of type 1 diabetes. Data were analysed with generalised estimating equations including adjustments for age, sex, smoking status, BMI, HbA_1c, serum creatinine, total cholesterol, urinary AER, insulin treatment dose and mean arterial pressure.

RESULTS

Increases were noted in all biomarkers except sE-selectin, which decreased over time. Levels differed from baseline at 2-4 years and preceded the increase in pulse pressure, which occurred at 8-10 years after the onset of type 1 diabetes. Higher levels of sICAM-1 and sVCAM-1, but not CRP or sE-selectin, at baseline and throughout the 20 year follow-up, were significantly associated with higher (changes in) pulse pressure at subsequent time points. Higher levels of sVCAM-1 at baseline and during follow-up were also significantly associated with the prevalence (OR 3.60 [95% CI 1.36, 9.53] and OR 2.28 [1.03, 5.25], respectively) and incidence (OR 2.89 [1.08, 7.75] and OR 3.06 [1.01, 9.26], respectively) of hypertension. We also investigated the longitudinal associations between BP or hypertension as determinants of subsequent (changes in) levels of CRP, sICAM-1, sVCAM-1 and sE-selectin, but did not find evidence to support a reverse causality hypothesis.

CONCLUSIONS/INTERPRETATION

These findings support the involvement of vascular endothelial dysfunction and inflammation in the development of premature arterial stiffening and hypertension in type 1 diabetes.

Elevated Serum Levels of Soluble TNF Receptors and Adhesion Molecules Are Associated with Diabetic Retinopathy in Patients with Type-1 Diabetes

Aims. To examine the association of the serum levels of TNF receptors, adhesion molecules, and inflammatory mediators with diabetic retinopathy (DR) in T1D patients. Methods. Using the multiplex immunoassay, we measured serum levels of eight proteins in 678 T1D subjects aged 20–75 years. Comparisons were made between 482 T1D patients with no complications and 196 T1D patients with DR. Results. The levels of sTNFR-I, sTNFR-II, CRP, SAA, sgp130, sIL6R, sVCAM1, and sICAM1 were significantly higher in the T1D patients with DR as compared to T1D patients with no complications. Multivariate logistic regression analysis revealed significant association for five proteins after adjustment for age, sex, and disease duration (sTNFR-I: OR = 1.57, sgp130: OR = 1.43, sVCAM1: OR = 1.27, sICAM1: OR = 1.42, and CRP: OR = 1.15). Conditional logistic regression on matched paired data revealed that subjects in the top quartile for sTNFR-I (OR = 2.13), sTNFR-II (OR = 1.66), sgp130 (OR = 1.82), sIL6R (OR = 1.75), sVCAM1 (OR = 1.98), sICAM1 (OR = 2.23), CRP (OR = 2.40) and SAA (OR = 2.03), had the highest odds of having DR. Conclusions. The circulating markers of inflammation, endothelial injury, and TNF signaling are significantly associated with DR in patients with T1D. TNFR-I and TNFR-II receptors are highly correlated, but DR associated more strongly with TNFR-I in these patients.

Serum adiponectin and hsCRP levels and non-invasive radiological methods in the early diagnosis of cardiovascular system complications in children and adolescents with type 1 diabetes mellitus

OBJECTIVE

Adiponectin and high-sensitivity C-reactive protein (hsCRP) can be used as early biochemical markers of cardiovascular diseases (CVDs). Radiologically, non-invasive flow-mediated dilation (FMD) of the brachial artery and carotid intima-media thickness (CIMT) measurements may be used as indicators in the early diagnosis of CVDs. To compare the biochemical markers of atherosclerosis with radiological markers of CVDs (CIMT, FMD, ventricular systolic and diastolic functions) and to assess the relationship of these parameters with metabolic control in diabetic children and adolescents.

METHODS

A total of 55 patients with type 1 diabetes mellitus (T1DM) of at least 5-year duration and 30 healthy subjects were included in the study. Serum adiponectin, hsCRP, hemoglobin A1c (HbA1c), and lipid levels were evaluated in the patients and in the controls. CIMT, FMD, ventricular systolic and diastolic functions were assessed by echocardiography.

RESULTS

Mean age of the patients with diabetes was 17.6 years; mean diabetes duration was 10.4 years. Mean serum hsCRP was elevated in children with diabetes (0.21±0.31 vs. 0.10±0.16 μg/mL, p=0.00), while no significant difference from the controls was found in adiponectin levels. Mean CIMT was significantly higher in diabetic children compared to the control group (0.53±0.11 vs. 0.34±0.46 mm, p=0.00). Mean FMD of the diabetic children was significantly lower than that of the controls (6.86±2.85% vs. 12.13±1.99%, p=0.00). Diabetes duration was positively correlated with CIMT and negatively correlated with FMD. Right ventricular (RV) and left ventricular (LV) myocardial performance index (MPI) were higher in the patient group (p=0.00).

CONCLUSIONS

Our data suggest that in addition to standard echocardiography, tissue Doppler echocardiography, FMD, and CIMT can be used as early-stage radiological markers and hsCRP as an early-stage biochemical marker of atherosclerosis in the routine follow-up of T1DM patients.

Arterial stiffness is increased in patients with type 1 diabetes without cardiovascular disease: a potential role of low-grade inflammation

OBJECTIVE

To investigate the relationship between arterial stiffness and low-grade inflammation in subjects with type 1 diabetes without clinical cardiovascular disease.

RESEARCH DESIGN AND METHODS

Sixty-eight patients with type 1 diabetes and 68 age- and sex-matched healthy subjects were evaluated. Arterial stiffness was assessed by aortic pulse wave velocity (aPWV). Serum concentrations of high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, and soluble fractions of tumor necrosis factor-α receptors 1 and 2 (sTNFαR1 and sTNFαR2, respectively) were measured. All statistical analyses were stratified by sex.

RESULTS

Subjects with diabetes had a higher aPWV compared with healthy control subjects (men: 6.9 vs. 6.3 m/s, P < 0.001; women: 6.4 vs. 6.0 m/s, P = 0.023). These differences remained significant after adjusting for cardiovascular risk factors. Men with diabetes had higher concentrations of hsCRP (1.2 vs. 0.6 mg/L; P = 0.036), IL-6 (0.6 vs. 0.3 pg/mL; P = 0.002), sTNFαR1 (2,739 vs. 1,410 pg/mL; P < 0.001), and sTNFαR2 (2,774 vs. 2,060 pg/mL; P < 0.001). Women with diabetes only had higher concentrations of IL-6 (0.6 vs. 0.4 pg/mL; P = 0.039). In men with diabetes, aPWV correlated positively with hsCRP (r = 0.389; P = 0.031) and IL-6 (r = 0.447; P = 0.008), whereas in women with diabetes no significant correlation was found. In men, multiple linear regression analysis showed that the following variables were associated independently with aPWV: age, BMI, type 1 diabetes, and low-grade inflammation (R(2) = 0.543). In women, these variables were age, BMI, mean arterial pressure, and type 1 diabetes (R(2) = 0.550).

CONCLUSIONS

Arterial stiffness assessed as aPWV is increased in patients with type 1 diabetes without clinical cardiovascular disease, independently of classical cardiovascular risk factors. In men with type 1 diabetes, low-grade inflammation is independently associated with arterial stiffness.

Insulin resistance, low-grade inflammation and type 1 diabetes mellitus

To assess the relationships between insulin resistance and low-grade inflammation in subjects with type 1 diabetes mellitus (T1DM) who do not have clinical macrovascular complications. A total of 120 subjects diagnosed with T1DM 14 years before were evaluated for the following: (1) sex, age, body mass index, waist-to-hip ratio (WHR), blood pressure, smoking, alcohol intake, insulin dose, HbA1c and lipid profile; (2) microvascular complications; (3) plasma concentrations of soluble fractions of tumour necrosis factor-α receptors type 1 and 2, interleukin-6, adiponectin, leptin and high-sensitivity C-reactive protein (hs-CRP); and (4) insulin resistance (estimation of the glucose disposal rate-eGDR). Those subjects with an eGDR below the median of the same sex group were classified as insulin resistant and the others as insulin sensitive. Insulin-resistant men, compared to the insulin-sensitive, had higher WHR (0.89 ± 0.08 vs. 0.83 ± 0.05; P < 0.01), higher systolic [121 (118-125) vs. 114 (108-120) mmHg; P = 0.01] and diastolic [73 (66-80) vs. 67 (70-73) mmHg; P = 0.02] blood pressures, higher HbA1c values [8.7 (8.1-9.9) vs. 7.5 (7.2-8.0) %; P < 0.01] and higher hs-CRP concentrations [1.16 (0.61-3.20) vs. 0.49 (0.31-0.82) mg/dl; P = 0.01], but no other significant differences between groups were found. Insulin-resistant women had higher WHR and HbA1c values, compared to the insulin-sensitive, but they did not have any other differences. In men, hs-CRP correlated significantly with WHR and HbA1c (r = 0.363; P = 0.016 and r = 0.317; P = 0.036, respectively), after adjusting for age, alcohol intake, smoking and microvascular complications. Insulin-resistant men with T1DM have an increase in plasma concentrations of hs-CRP. Central obesity and HbA1c are its main determinants.

Influence of glucoregulation quality on C-reactive protein, interleukin-6 and tumor necrosis factor-alpha level in patients with diabetes type 1

BACKGROUND/AIM

Results of studies which have proved an increased inflammatory activity in diabetes type 1, have been published over recent years. One of possible mechanisms that are used to explain chronic inflammation in diabetes is the state of hyperglycemia leading to the enhanced synthesis of glycosylation end products (AGEs) which activate macrophages, increase the oxidative stress and affect the synthesis of interleukins (IL-1, IL-6), tumor necrosis factor-alpha (TNF-alpha) and C-reactive protein (CRP). The aim of the study was to determine the inflammatory markers (CRP, IL-6, TNF-alpha) in patients with diabetes type 1 and to establish their correlation with glucoregulation parameters and other cardiovascular risk factors as well as to compare them with the healthy controls.

METHODS

The study included 76 patients with diabetes type 1 and 30 healthy controls. We determined values of inflammatory markers (CRP, IL-6, TNF-alpha) and glucoregulation parameters (fasting glucose HbA(1c)).

RESULTS

The values of CRP (p = 0.014), IL-6 (p = 0.020) and TNF-alpha (p = 0.037) were statistically significantly higher in the diabetic patients than in the healthy controls. There was a positive correlation between CRP with postprandial glycemia (p = 0.004); the multivariate regression analysis revealed a statistically significant correlation between CRP and age (p = 0.001), smoking (p = 0.055), fasting glucose (p = 0.021) and triglycerides (p = 0.048) as well as between IL-6 and LDL-cholesterol (p = 0.009). No statistically significant correlations were found between glycosilated hemoglobin (HbA(1c)) and the inflammatory markers (CRP, IL-6 and TNF-alpha).

CONCLUSION

The patients with type 1 diabetes were found to have a low level of inflammatory activity manifested by the increased values of CRP, IL-6 and TNF-alpha.

Increased serum C-reactive protein concentration is associated with body mass index but not with glycated haemoglobin in patients with type 1 diabetes mellitus with body mass index within normal range

This study investigated whether serum C-reactive protein (CRP) concentration is increased in patients with type 1 diabetes mellitus with a normal body mass index (BMI) and whether BMI, glycated haemoglobin (HbA1c) and CRP are correlated in patients with type 1 diabetes. High-sensitivity CRP was determined by immunonephelometry and HbA1c by an immunoturbidimetric method in 30 patients with type 1 diabetes and 30 healthy individuals matched for age, sex and BMI. Median serum CRP concentration in patients with type 1 diabetes (1.34 mg/L) was significantly higher than healthy individuals (0.2 mg/L; p<0.0001). Positive correlation between CRP and BMI was observed (rho=0.598; p<0.0001), but no significant correlation was observed between CRP and HbA1c (rho=0.285; p=NS) in patients with type 1 diabetes. Increased CRP levels in type 1 diabetes patients do not appear to be associated with glycaemic control, and may reflect low-grade inflammation associated with atherosclerosis, as well as activation of innate immune activity.

Obesity and coronary artery calcium in diabetes: the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study

BACKGROUND

The aim was to examine whether excess weight is associated with coronary artery calcium (CAC), independent of metabolic parameters in adults with type 1 diabetes (T1D).

METHODS

Subjects between 19 and 56 years of age with T1D (n=621) from the Coronary Artery Calcification in Type 1 Diabetes study were classified as abnormal on four metabolic parameters: blood pressure ≥130/85 mm Hg or on antihypertensive treatment; high-density lipoprotein-cholesterol of <40 mg/dL for men or <50 mg/dL for women; triglycerides of ≥150 mg/dL; or C-reactive protein of ≥3 μg/mL. Study participants with two or more abnormal parameters were classified as metabolically abnormal. Weight categories by body mass index were normal (<25 kg/m(2)), overweight (25 to <30 kg/m(2)), and obese (≥30 kg/m(2)). CAC was measured at two visits 6.0±0.5 years apart. Progression of CAC was defined as an increase in square root transformed CAC volume of ≥2.5 mm(3) or development of clinical coronary artery disease.

RESULTS

Among subjects with T1D, 48% of normal, 61% of overweight, and 73% of obese participants were classified as metabolically abnormal (P<0.0001). Overweight and obesity were independently associated with presence of CAC, independent of presence of metabolically abnormal. Obesity but not overweight was associated with CAC progression, independent of the other cardiovascular risk factors.

CONCLUSIONS

Although obesity is known to increase cardiovascular disease risk through inducing metabolic abnormalities such as dyslipidemia, hypertension, and inflammation, it is also a strong predictor of subclinical atherosclerosis progression in adults with T1D independent of these factors.

Hs-CRP is associated with weight, BMI, and female sex but not with endothelial function in children with type 1 diabetes

BACKGROUND

Atherosclerosis is an inflammatory process, and high-sensitivity C-reactive protein (Hs-CRP), a marker of inflammation, predicts cardiovascular events in adults. Vascular endothelial and smooth muscle dysfunction, measurable precursors of atherosclerosis, begin in childhood. Therefore, we sought to determine if Hs-CRP is associated with vascular endothelial and smooth muscle dysfunction in children with type 1 diabetes mellitus (T1DM) and healthy control subjects.

METHODS

Hs-CRP and endothelial function assessed by flow-mediated dilatation (FMD) and smooth muscle function assessed by glyceryl-trinitrate (GTN)-induced dilatation were measured in 121 subjects with T1DM aged 14.1 (2.9) yr, of whom 31 were also studied at 4 and 8 wk, and in 33 healthy controls aged 14.2 (3.6) yr.

RESULTS

Hs-CRP did not differ between subjects with T1DM and healthy, age-matched controls. In both controls and subjects with T1DM, Hs-CRP did not relate to FMD or GTN at baseline or at intervals over 8 wk in T1DM. Hs-CRP did not change over time. In T1DM, but not healthy controls, Hs-CRP related to body mass index (BMI) z-score (r = 0.47, p < 0.001), weight z-score (r = 0.41, p < 0.001), and female sex (p = 0.008).

CONCLUSIONS

Hs-CRP is not associated with early vascular dysfunction in children with T1DM. However, in children and adolescents with T1DM, Hs-CRP was associated with female sex and children with higher BMI, suggesting that these groups may be at greater cardiovascular risk. Maintenance of a healthy BMI may be important in the prevention of vascular disease of T1DM.

Cross-sectional associations of C-reactive protein with vascular risk factors and vascular complications in the DCCT/EDIC cohort

OBJECTIVE

To determine the relationships between C-reactive protein (CRP) levels and features of Type 1 diabetes.

RESEARCH DESIGN AND METHODS

Serum CRP was measured by nephelometry in a cross-sectional study of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort (n=983) and nondiabetic subjects (n=71).

RESULTS

CRP levels [geometric mean (95% CI)] were higher in diabetic than in control subjects, 1.6 (1.5-1.7) vs. 1.2 (1.1-1.5) mg/l, P=.019. CRP was higher in diabetic women (n=438) than in men (n=545) [2.0 (1.8-2.3) vs. 1.3 (1.2-1.5), P<.001]. Diabetic subjects formerly in the DCCT intensive treatment group had higher CRP levels than those who were randomized to the conventional treatment group [1.8 (1.6-1.9), n=479 vs. 1.5 (1.3-1.6), n=456, P=.010], attributable to greater BMI in the prior intensive group. In diabetes, CRP correlated with HbA(1c) (r=0.13, P<.0001) and with insulin resistance traits: BMI (r=0.34, P<.0001), waist-to-hip ratio (WHR; males: r=0.35, P<.0001; females: r=0.22, P<.0001), diastolic blood pressure (r=0.07, P=.025), triglycerides (r=0.19, P<.0001), apoB (r=0.22, P<.0001), LDL particle concentration (r=0.26, P<.0001), and LDL particle size (r=-0.22, P<.0001). CRP was not associated with complications. Significant independent predictors of CRP in diabetes were gender, BMI, WHR, concurrent HbA(1c), and oral contraceptive pill use.

CONCLUSIONS

CRP was elevated relative to nondiabetic subjects, and in diabetes was higher in females. Elevated CRP in Type 1 diabetes was associated with poor glycemic control, larger body habitus, and other factors that comprise the insulin resistance syndrome. Nevertheless, CRP levels were not associated with complications. Longitudinal studies are warranted.

Relationship of highly sensitive C-reactive protein and lipid levels in adolescents with type 1 diabetes mellitus

BACKGROUND

Atherosclerosis appears to begin in youth with type 1 diabetes mellitus (T1DM). Highly sensitive C-reactive protein (hsCRP) is an independent marker of cardiovascular disease (CVD) risk in adults, but its relation to dyslipidemia and other CVD risk factors in adolescents with T1DM is unknown.

OBJECTIVE

To study the association between lipids and hsCRP in youth with T1DM.

DESIGN

Cross-sectional cohort.

METHODS

hsCRP and fasting lipids were measured in 74 patients with T1DM, mean age 16.2 +/- 2.62 yr, mean duration of diabetes 7.3 +/- 4.0 yr, and mean hemoglobin A1c (HbA1c) 8.5 +/- 1.3%. According to the American Heart Association/Centers for Disease Control recommendations, hsCRP values were divided into three groups: group 1: <1.0 mg/L, low CVD risk; group 2: 1.0-3.0 mg/L, average CVD risk; and group 3: >3 mg/L, high CVD risk. Univariate linear regression between hsCRP and lipid and clinical parameters was used, with adjustment for age.

RESULTS

hsCRP was significantly associated with triglycerides (Tg), apoB, systolic blood pressure (SBP), and diastolic blood pressure (DBP). Subjects in the high CVD risk group had no further worsening of lipids or BP, except for a higher Tg level. ApoB, SBP, and DBP were elevated in females with hsCRP > or =1 compared with the low-risk group, and high-density lipoprotein was decreased. In males, this difference was only significant for SBP.

CONCLUSIONS

Elevation of hsCRP to a level > or =1.0 mg/L appears to be associated with elevated lipid levels in adolescents with T1DM, particularly in females. hsCRP is a marker in youth that clusters with dyslipidemia and may indicate an increased CVD risk in youth with T1DM.

High-normal C-reactive protein levels do not affect the vitamin A transport complex in serum of children and adolescents with type 1 diabetes

Type 1 diabetes is associated with the presence of inflammation, which in turn affects parameters used to assess the vitamin A status. In the present study, we evaluated the influence of inflammatory status on retinol, retinol-binding protein 4 (RBP4), and transthyretin (TTR) in children and adolescents with type 1 diabetes. A total of 40 children with type 1 diabetes (median age, 14.2 y; median BMI-SDS, 0.53; median diabetes duration, 5.8 y; median HbA1c, 7.3%) and 46 healthy subjects (median age, 12.8 y; median BMI-SDS, 0.34; median HbA1c 5.4%) were recruited. Serum levels of CRP were significantly elevated (p = 0.005) and retinol concentrations were significantly lower (p = 0.02) in children and adolescents with type 1 diabetes compared with healthy subjects. Serum RBP4 and TTR showed no differences between the groups. Healthy children with CRP levels above 0.6 mg/L had significant lower levels of retinol (p = 0.03). This was not observed in children with type 1 diabetes. The results suggest that, in contrast to healthy children, minor CRP elevation does not affect vitamin A transport complex in serum of children with type 1 diabetes.

Plasma total homocysteine levels in children with type 1 diabetes: relationship with vitamin status, methylene tetrahydrofolate reductase genotype, disease parameters and coronary risk factors

The objectives of this study were: to determine plasma total homocysteine tHcy levels and the prevalence of hyperhomocysteinemia in children with type 1 diabetes, to determine correlates of plasma tHcy levels with nutritional factor such as serum folic acid and vitamin B12 levels, genetic factors as methylenetetrahydrofolate reductase MTHFR gene polymorphism (C677T and A1298C), to attempt to identify possible dependencies between tHcy and the degree of metabolic control, the duration of the disease and presence of complications, and also to determine the relationship between other coronary risk factors. Plasma tHcy levels and other related parameters performed in 32 children with type 1 diabetes and 23 age-sex matched healthy children. Median tHcy level was higher in the patient group (11.38, 3.28 to 66.01 micromol/l) than the control group (8.78, 1.06 to 13.66 mol/l) (p < 0.05). A 28.1 per cent (n = 9) of the diabetic patients had hyperhomocysteinemia, four case with mild and five case with moderate. Plasma tHcy levels were positively correlated with disease duration and C-reactive protein CRP levels and negatively correlated with disease onset age. The hyperhomocysteinemic group had higher CRP levels, longer disease duration and early onset of disease than non-hyperhomocysteinemic group (p < 0.05 in both), respectively. The hyperhomocysteinemic group had significantly higher CRP, total cholesterol, triglyceride, apolipoprotein B, systolic blood pressure, blood urea nitrogen and creatinine levels and lower folate, apolipoprotein A1 levels and glomerular filtration rate values than the control group. Plasma tHcy levels were higher in diabetic children with poor metabolic control. Because of hyperhomocysteinemia is common in diabetic children and plasma tHcy levels correlated with early onset of the disease and disease duration, we recommend the usage of plasma tHcy levels as a risk indicator parameter with other coronary risk factor for detecting and preventing cardiovascular disease in diabetic children.

High-sensitivity C-reactive protein as cardiovascular risk marker in patients with diabetes mellitus

C-reactive protein (CRP) is a liver-derived pattern recognition molecule that is increased in inflammatory states. It rapidly increases within hours after tissue injury, and it is suggested that it is part of the innate immune system and contributes to host defense. Since cardiovascular disease is at least in part an inflammatory process, CRP has been investigated in the context of arteriosclerosis and subsequent vascular disorders. Based on multiple epidemiological and intervention studies, minor CRP elevation [high-sensitivity CRP (hsCRP)] has been shown to be associated with future major cardiovascular risk (hsCRP:<1 mg/L=low risk; 1-3 mg/L=intermediate risk; 3-10 mg/L=high risk; >10 mg/L=unspecific elevation). It is recommended by the American Heart Association that patients at intermediate or high risk of coronary heart disease may benefit from measurement of hsCRP with regard to their individual risk prediction. Elevation of hsCRP is associated with increased risk of type 2 diabetes development in patients with all levels of metabolic syndrome. In type 1 and type 2 diabetes mellitus, hemoglobin A1c significantly correlates with hsCRP levels and future cardiovascular risk. Also, hsCRP levels increase with the stage of beta-cell dysfunction and insulin resistance. Non-diabetes drugs that have been shown to reduce hsCRP concentrations include aspirin, statins, cyclooxygenase-2 inhibitors, and fibrates. Recent intervention studies have also demonstrated the distinct efficacy of different anti-diabetes treatments on a variety of cardiovascular risk markers. Intensive insulin therapy may reduce inflammation, but this effect may be influenced by the degree of weight gain. Treatment with peroxisome proliferator-activated receptor gamma has lead to substantial reduction of hsCRP and other cardiovascular risk markers in several comparator studies. Since this effect was shown to be independent of the degree of glycemic improvement, it can be regarded as a classspecific effect. Whether these findings translate into a reduction of overall cardiovascular mortality will soon be shown by the currently running thiazolidinedione outcome studies. Positive results in these trials will further strengthen the value and acceptance of hsCRP, which is recommended as a predictive laboratory marker for cardiovascular disease risk also in patients with diabetes mellitus.

What does minor elevation of C-reactive protein signify?

Reports of the predictive value of minor elevation of serum C-reactive protein (CRP) levels (between 3 and 10 mg/L) for atherosclerotic events have generated considerable interest, as well as a degree of controversy and confusion. CRP concentrations in this range are found in about one third of the American population. To better understand the mechanisms underlying minor elevation of CRP, we have surveyed its reported associations with a variety of states and conditions. It has become clear that even minimal environmental irritants and inflammatory stimuli elicit a minor CRP response. Minor CRP elevation has been found associated with a number of genetic polymorphisms, with membership in different demographic and socioeconomic groups, with a variety of dietary patterns and with many medical conditions that are not apparently inflammatory. Finally, minor CRP elevation bears negative prognostic implications for many conditions, particularly age-related diseases, and predicts mortality in both diseased and apparently healthy individuals. In sum, minor CRP elevation is associated with a great many diverse conditions, some of which are, or may prove to be, causal. Many of these reported associations imply a mild degree of tissue stress or injury, suggesting the hypothesis that the presence of distressed cells, rather than a resulting inflammatory response, is commonly the stimulus for CRP production.

Family history of diabetes or cardiovascular disease and C-reactive protein concentration: findings from the National Health and Nutrition Examination Survey, 1999-2000

BACKGROUND

Prospective studies have suggested that C-reactive protein concentration is associated with diabetes and coronary heart disease. The presence of a family history of diabetes or coronary heart disease is considered a risk factor for these conditions. Whether a family history of diabetes or coronary heart disease is associated with C-reactive protein concentration is uncertain.

METHODS

A cross-sectional analysis was performed on data from the National Health and Nutrition Examination Survey 1999-2000, a nationally representative survey of the U.S. population. Family histories of diabetes and coronary heart disease were self-reported.

RESULTS

In unadjusted analyses (n=3187), the geometric mean concentration of C-reactive protein was 1.7 mg/L, 1.9 mg/L, and 2.6 mg/L for participants with 0, 1, and > or = 2 relatives with diabetes, respectively (p for linear trend <0.001). After adjustment for age, gender, race/ethnicity, education, smoking status, systolic blood pressure, total cholesterol concentration, body mass index, and alcohol intake, a family history of diabetes was not independently associated with C-reactive protein concentration (Wald chi-square p=0.228). Univariate and multivariate analyses of data on 3344 participants showed that a family history of coronary heart disease was not significantly associated with C-reactive protein concentration.

CONCLUSIONS

Family histories of diabetes or coronary heart disease were not independently associated with C-reactive protein concentration, suggesting that the association between such family histories and diabetes and coronary heart disease are not explained by C-reactive protein concentration or perhaps by inflammation. Additional study of this subject is recommended, however.

Effect of intensive glycemic control on levels of markers of inflammation in type 1 diabetes mellitus in the diabetes control and complications trial

BACKGROUND

Type 1 diabetes mellitus is associated with an increased risk of cardiovascular disease (CVD) that is not fully explained by conventional risk factors. The Diabetes Control and Complications Trial (DCCT) showed that intensive diabetes therapy reduced levels of LDL cholesterol and triglycerides but increased the risk of major weight gain, which might adversely affect CVD risk. The present study examined the effect of intensive therapy on levels of several markers of inflammation that have been linked to risk of CVD.

METHODS AND RESULTS

We measured levels of inflammatory biomarkers in stored baseline and 3-year follow-up serum specimens from a random sample of 385 participants in the DCCT, a multicenter trial in which 1441 subjects aged 13 to 39 years with type 1 diabetes mellitus were randomized to intensive or conventional diabetes treatment. The markers included high-sensitivity C-reactive protein (hsCRP), soluble intercellular adhesion molecule type 1 (sICAM-1), soluble vascular cell adhesion molecule type 1 (sVCAM-1), and the 55-kDa soluble tumor necrosis factor-alpha receptor 1 (sTNF-R1). We examined the effect of intensive therapy on the change in levels of the inflammatory markers. In unadjusted analyses, levels of hsCRP and sTNF-R1 increased in both treatment groups after 3 years of follow-up, with no significant difference between groups for hsCRP (P=0.53) but with a greater increase of sTNF-R1 in the intensive therapy group (P=0.002). In contrast, mean levels of sICAM-1 and sVCAM-1 decreased among participants assigned to intensive therapy, whereas they did not change among those in the conventional treatment group (P=0.03 for sICAM-1; P=0.03 for sVCAM-1). After adjustment for baseline levels and other factors, intensive therapy remained associated with a significant decrease in sICAM-1 (P=0.02) and an increase in sTNF-R1 (P=0.03). For hsCRP, there was a significant interaction between the top third of weight gain and treatment assignment (P=0.03). In subgroup analyses among subjects undergoing intensive therapy, hsCRP levels increased among those who gained the most weight, whereas it decreased among those in the bottom third of weight gain (P=0.0004).

CONCLUSIONS

Intensive therapy in patients with type 1 diabetes mellitus reduced levels of sICAM-1 and increased levels of sTNF-R1 and of hsCRP among those who gained weight. These data demonstrate that the effect of intensive therapy on inflammation is complex and, to the extent that hsCRP is a risk factor, suggest that the risk of atherosclerosis among diabetic patients may be influenced by the degree of weight gain while undergoing intensive therapy.

Retinopathy and hypertension affect serum high-sensitivity C-reactive protein levels in Type 2 diabetic patients

Several studies suggest that inflammation plays an important role in the pathogenesis of diabetes mellitus, as well as atherosclerosis, and acute-phase reactants have been proposed as monitors for the ongoing process of these diseases. We studied the clinical significance of serum high-sensitivity C-reactive protein (hs-CRP) in relation to chronic diabetic complications using 114 Japanese patients with Type 2 diabetes mellitus. The hs-CRP values were normalized by logarithmic transformation for statistical analysis. Retinopathy and hypertension were extracted as significant modulators for the hs-CRP value in the diabetic patients, in addition to previously known factors, age, and body mass index (BMI), by multivariate analysis. The hs-CRP level in normotensive diabetic patients without retinopathy was not significantly different from that of normal control participants after adjustment for age and BMI. The hs-CRP value was significantly high in the patients with hypertension, despite the existence or absence of diabetes. On the other hand, the hs-CRP level of the diabetic patients complicated with retinopathy was low especially in those with hypertension. The frequency of patients having an hs-CRP value above 1.0 mg/l who are thought to be at risk for cardiovascular diseases was also high in the patients complicated with hypertension and low in the diabetic patients with retinopathy. These results indicate that the presence or absence of hypertension and retinopathy should be taken into consideration for the interpretation of the serum hs-CRP in diabetic patients.

Elevated C-reactive protein levels in the development of type 1 diabetes

Elevated C-reactive protein (CRP) levels have previously been described before the onset of type 2 diabetes and gestational diabetes. We hypothesized that inflammation, as reflected by elevated CRP levels, can help predict development of islet autoimmunity or type 1 diabetes. Children at risk for type 1 diabetes and followed in the Diabetes Autoimmunity Study of the Young (DAISY) had blood samples drawn and frozen serum saved at various intervals after birth. CRP was measured using a high-sensitivity sandwich enzyme immunoassay. Islet autoantibodies (IAs) were measured using biochemical immunoassays. Elevations in CRP concentrations were significantly more frequent (P < 0.01) in children who later developed type 1 diabetes (8 of 16 children) than in children negative for IAs at their last testing (3 of 26). Children with one or more positive IA were more likely to have elevated CRP concentrations (15 of 36) than IA-negative children (3 of 26; P < 0.01). The finding of elevated CRP levels in infants and young children before the onset of type 1 diabetes adds to the evidence that the disease is an immunoinflammatory disorder. The elevated CRP levels may provide an additional marker for risk of progression to type 1 diabetes.

Does aggressive statin therapy offer improved cholesterol-independent benefits compared to conventional statin treatment?

There is currently intense research interest in the properties of HMG-CoA reductase inhibitors (statins) beyond their well-documented lipid-lowering action. Studies have consistently demonstrated that administration of statin therapy decreases levels of the inflammatory marker C-reactive protein (CRP), a marker associated with an increased risk of cardiovascular events. This effect appears to be independent of the extent of reduction in total or LDL-cholesterol. Statins also appear to improve endothelial dysfunction by increasing endothelium-dependent vasodilatation. There is also evidence that statins inhibit fibrin formation and thrombus development, an effect that which would be clinically beneficial following plaque fissure or rupture. Early preclinical and clinical evidence suggests that there are quantitative differences between statin regimens in terms of their cholesterol-independent properties. Trials comparing equipotent doses of different statins, based on lipid-lowering efficacy, have not reported any differences in cholesterol-independent properties. However, the current evidence base indicates that more aggressive statin regimens are associated with an enhanced anti-inflammatory effect. Intensive lipid-lowering using statin therapy generates a greater reduction in mortality than standard lipid management, and it is possible that enhanced cholesterol-independent effects may account for some of this excess benefit.

Prognostic value of plasma C-reactive protein and fibrinogen determinations in patients with acute myocardial infarction treated with thrombolysis

OBJECTIVES

To investigate the prognostic value of plasma C-reactive protein (CRP) and fibrinogen determinations in patients with acute myocardial infarction treated with thrombolysis.

DESIGN

Longitudinal study of morbidity and mortality.

SETTING

Coronary care unit at Danderyd Hospital, Stockholm, Sweden.

SUBJECTS

A total of 222 patients aged 75 years or below, treated with thrombolysis because of typical symptoms of myocardial infarction and electrocardiogram showing ST-segment elevation or bundle branch block were included in the study. The patients were followed for 24-60 months (mean 40 +/- 16 months).

MAIN OUTCOME MEASURES

Cardiovascular death or new myocardial infarction.

RESULTS

Concentrations of CRP were significantly higher at 48 h than at 3 months, whilst the levels of fibrinogen were similar. CRP and fibrinogen concentrations measured during the acute phase of myocardial infarction were associated with cardiovascular death or a new myocardial infarction during follow-up in univariate analysis. CRP levels measured 3 months after the acute event were not associated with subsequent events whereas fibrinogen concentrations showed a borderline prognostic significance (P = 0.05). When CRP and fibrinogen were entered into multivariate analysis together with the previously established prognostic factors in the patient group (age, diabetes mellitus and left ventricular function), these markers of inflammation did not add further prognostic information.

CONCLUSION

C-reactive protein and fibrinogen do not carry the same independent prognostic information after acute myocardial infarction treated with thrombolysis as in studies previously reported for patients with unstable angina or non-Q-wave myocardial infarction.

Vascular risk factors and markers of endothelial function as determinants of inflammatory markers in type 1 diabetes: the EURODIAB Prospective Complications Study

OBJECTIVE

Inflammatory activity is increased in type 1 diabetes and may predispose to vascular disease. Its origin is not clear. We therefore investigated determinants of inflammation in type 1 diabetes.

RESEARCH DESIGN AND METHODS

We performed a nested case-control study from the EURODIAB Prospective Complications Study of 543 European individuals having type 1 diabetes (278 men), diagnosed at <36 years of age. Case subjects (n = 348) were those with one or more complications of diabetes; control subjects (n = 195) were all those with no evidence of any complication. We determined levels of C-reactive protein, interleukin-6, and tumor necrosis factor-alpha, combined them in a "general score of inflammatory markers," and investigated their associations with vascular risk factors and markers of endothelial dysfunction by use of multiple linear regression analysis.

RESULTS

Measures of inflammation were associated with sex, diabetes duration, glycemic control, the advanced glycation end product pentosidine, BMI, HDL cholesterol, triglycerides, and systolic blood pressure (standardized betas with the general score of inflammatory markers 0.15 [P = 0.002], 0.15 [P = 0.006], 0.18 [P < 0.0001], 0.12 [P = 0.005], 0.10 [P = 0.057], -0.15 [P = 0.001], 0.16 [P < 0.0001], and 0.09 [P = 0.042], respectively). In addition, measures of inflammation were strongly associated with markers of endothelial dysfunction, soluble vascular cell adhesion molecule-1, and soluble E-selectin (standardized betas with the general score of inflammatory markers 0.28 [P < 0.0001] and 0.19 [P < 0.0001]).

CONCLUSIONS

We have shown that conventional risk factors for vascular disease and endothelial adhesion molecules are important determinants of inflammation in type 1 diabetic individuals, suggesting that strategies to decrease inflammatory activity in type 1 diabetes should focus not only on control of conventional risk factors, but also on improvement of endothelial function.

Elevated C-reactive protein associates with early-stage carotid atherosclerosis in young subjects with type 1 diabetes

OBJECTIVE

To evaluate whether low-grade inflammation contributes to early-stage advanced carotid atherosclerosis in young subjects with type 1 diabetes.

RESEARCH DESIGN AND METHODS

The mean and maximum (max) intima-media thicknesses (IMT) of the carotid artery were assessed using ultrasound B-mode imaging in 55 patients with type 1 diabetes (22 men and 33 women, aged 22.1 +/- 3.6 years (+/- SD), duration of diabetes 14.2 +/- 5.7 years) and 75 age-matched healthy nondiabetic subjects (28 men and 47 women). High-sensitive C-reactive protein (hs-CRP) levels were measured with a latex-enhanced immunonephelometer.

RESULTS

The patients with type 1 diabetes had significantly higher hs-CRP levels (median 0.35, range 0.05-1.47 mg/l vs. median 0.14, range 0.05-1.44 mg/l; P = 0.001) as well as significantly higher mean IMT and max IMT than the nondiabetic subjects (mean IMT 0.76 +/- 0.09 vs. 0.72 +/- 0.04 mm, P = 0.003; max IMT 0.84 +/- 0.11 vs. 0.77 +/- 0.06 mm, P < 0.0001). Hs-CRP levels were significantly correlated with the mean and max IMT of patients with type 1 diabetes and with the max IMT of nondiabetic patients. Multivariate regression analyses for both diabetic and nondiabetic subjects as a single group showed that hs-CRP levels are independently correlated with the mean IMT and max IMT levels (P = 0.002 and P = 0.023, respectively) as well as with diastolic blood pressure, sex, and duration of diabetes.

CONCLUSIONS

Our data indicate that hs-CRP levels are elevated in young patients with type 1 diabetes, possibly corresponding with early-stage advanced carotid atherosclerosis.