Search

Background: Data from the Centers for Disease Control show that approximately one-quarter of adults have elevated triglyceride (TG) levels. Some clinical trials, but not all, have demonstrated that pharmacologic treatment of high TG levels in patients already on statin therapy reduces the rate of major vascular events such as myocardial infarction and stroke. We assessed the prevalence of elevated TG levels in patients with asymptomatic carotid stenosis (CS), and medical conditions associated with high TG., Methods: Baseline lipid profiles from patients enrolled in the Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST 2) were analyzed. to determine treatment eligibility for high TG levels using the criteria established by the REDUCE-IT trial (triglyceride levels ≥150 mg/dL with LDL managed by a statin to <100 mg/dL). Equally assessed was the percentage of patients who were using pharmacologic treatment for high TG levels at study entry. Demographic factors and baseline medical conditions associated with high (>150 mg/dl) TG values were also analyzed. Chi-square and t=tests were used to assess baseline factors and abnormal TG values., Results: As of October 2023, of 2377 randomized CREST-2 patients, 2328 (98 %) (mean age 70.0 years, 63 % men) had baseline lipid profiles suitable for analysis. Among 1961 (84 %) patients who met REDUCE-IT criteria, analysis of lipid profiles revealed that 20.5 % of the patients were eligible for treatment of high triglycerides. Of the 1464 patients with fasting lipid profiles, 17.8 % were eligible for treatment. The median TG value was 205 (IQR 91) mg/dl in the total population. TG levels of 150 mg/dl or higher were strongly associated with hypertension, diabetes, obesity, high hemoglobin A1c, and reduced physical activity (all p<0.0001)., Conclusions: Elevated TG levels are strongly associated with diabetes, hypertension, obesity, and reduced physical activity. Further research is needed on whether treatment of elevated TG levels in patients with asymptomatic carotid stenosis confers benefit., Competing Interests: Declaration of competing interest Nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Clinical studies have shown that periodontitis is associated with non-alcoholic fatty liver disease (NAFLD). However, it remains unclear if periodontitis contributes to the progression of NAFLD. In this study, we generated a mouse model with high-fat diet (HFD)-induced metabolic syndrome (MetS) and NAFLD and oral P. gingivalis inoculation-induced periodontitis. Results showed that the presence of periodontitis increased insulin resistance and hepatic inflammation and exacerbated the progression of NAFLD. To determine the role of sphingolipid metabolism in the association between NAFLD and periodontitis, we also treated mice with imipramine, an inhibitor of acid sphingomyelinase (ASMase), and demonstrated that imipramine treatment significantly alleviated insulin resistance and hepatic inflammation, and improved NAFLD. Studies performed in vitro showed that lipopolysaccharide (LPS) and palmitic acid (PA), a major saturated fatty acid associated with MetS and NAFLD, synergistically increased the production of ceramide, a bioactive sphingolipid involved in NAFLD progression in macrophages but imipramine effectively reversed the ceramide production stimulated by LPS and PA. Taken together, this study showed for the first time that the presence of periodontitis contributed to the progression of NAFLD, likely due to alterations in sphingolipid metabolism that led to exacerbated insulin resistance and hepatic inflammation. This study also showed that targeting ASMase with imipramine improves NAFLD by reducing insulin resistance and hepatic inflammation.

We determined the relationship between plasma kallikrein and cardiovascular disease (CVD) outcomes as well as major adverse cardiovascular events (MACE) in the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) cohort of type 1 diabetes (T1D). Plasma kallikrein levels were measured longitudinally in 693 subjects at DCCT baseline (1983-1989), midpoint (1988-1991), and end (1993) and at EDIC years 4-6 (1997-1999), 8-10 (2001-2003), and 11-13 (2004-2006). Cox proportional hazards regression models assessed the association between plasma kallikrein levels and the risk of CVD. In unadjusted models, higher plasma kallikrein levels were associated with higher risk of any CVD during DCCT/EDIC (hazard ratio [HR] = 1.16 per 20 nmol/L higher levels of plasma kallikrein; P = 0.0177) as well as over the EDIC-only period (HR = 1.22; P = 0.0024). The association between plasma kallikrein levels and the risk of any CVD remained significant during the EDIC follow-up after adjustment for age and mean HbA 1c (HR = 1.20; P = 0.0082) and in the fully adjusted model for other CVD risk factors (HR = 1.17; P = 0.0330). For MACE, higher plasma kallikrein levels were associated with higher risk in the unadjusted (HR = 1.25; P = 0.0145), minimally adjusted (HR = 1.23; P = 0.0417, and fully adjusted (HR = 1.27; P = 0.0328) models for EDIC only. These novel findings indicate that plasma kallikrein level associates with the risk of any CVD and MACE in T1D individuals., (© 2020 by the American Diabetes Association.)

Background and Purpose: The CREST2 trial (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis) is comparing intensive medical management (IMM) alone to IMM plus revascularization with carotid endarterectomy or transfemoral carotid artery stenting for preventing stroke or death within 44 days after randomization or ipsilateral ischemic stroke thereafter. There are extensive clinical trial data on outcomes after revascularization of asymptomatic carotid stenosis, but not for IMM. As such, the experimental treatment in CREST2 is IMM, which is described in this article., Methods: IMM consists of aspirin 325 mg/day and intensive risk factor management, primarily targeting systolic blood pressure <130 mm Hg (initially systolic blood pressure <140 mm Hg) and LDL (low-density lipoprotein) cholesterol <70 mg/dL. Secondary risk factor targets focus on tobacco smoking, non-HDL (high-density lipoprotein), HbA1c (hemoglobin A1c), physical activity, and weight. Risk factor management is performed by site personnel and a lifestyle coaching program delivered by telephone. We report interim risk factor data on 1618 patients at baseline and last follow-up through 24 months., Results: The mean baseline LDL of 80.5 mg/dL improved to 66.7 mg/dL. The mean baseline systolic blood pressure of 139.7 mm Hg improved to 130.3 mm Hg. The proportion of patients in-target improved from 43% to 61% for systolic blood pressure <130 mm Hg and from 45% to 67% for LDL<70 mg/dL (both changes P <0.001)., Conclusions: The rigorous multimodal approach to intensive stroke risk factor management in CREST2 has resulted in significant improvements in risk factor control that will enable a comparison of cutting-edge medical care to revascularization in patients with asymptomatic carotid stenosis. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02089217.

The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study demonstrated that intensive glucose control reduced the risk of developing diabetic peripheral neuropathy (DPN) and cardiovascular autonomic neuropathy (CAN). We evaluated multiple risk factors and phenotypes associated with DPN and CAN in this large, well-characterized cohort of participants with type 1 diabetes, followed for >23 years. DPN was defined by symptoms, signs, and nerve conduction study abnormalities in ≥2 nerves; CAN was assessed using standardized cardiovascular reflex tests. Generalized estimating equation models assessed the association of DPN and CAN with individual risk factors measured repeatedly. During DCCT/EDIC, 33% of participants developed DPN and 44% CAN. Higher mean HbA 1c was the most significant risk factor for DPN, followed by older age, longer duration, greater height, macroalbuminuria, higher mean pulse rate, β-blocker use, and sustained albuminuria. The most significant risk factor for CAN was older age, followed by higher mean HbA 1c , sustained albuminuria, longer duration of type 1 diabetes, higher mean pulse rate, higher mean systolic blood pressure, β-blocker use, estimated glomerular filtration rate <60 mL/min/1.73 m 2 , higher most recent pulse rate, and cigarette smoking. These findings identify risk factors and phenotypes of participants with diabetic neuropathy that can be used in the design of new interventional trials and for personalized approaches to neuropathy prevention., (© 2020 by the American Diabetes Association.)

Objective: The Diabetes Control and Complications Trial (DCCT) and its observational follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) demonstrated the dominant role of glycemia, second only to age, as a risk factor for a first cardiovascular event in type 1 diabetes (T1D). We now investigate the association between established risk factors and the total cardiovascular disease (CVD) burden, including subsequent (i.e., recurrent) events., Research Design and Methods: CVD events in the 1,441 DCCT/EDIC participants were analyzed separately by type (CVD death, acute myocardial infarction [MI], stroke, silent MI, angina, percutaneous transluminal coronary angioplasty/coronary artery bypass graft [PTCA/CABG], and congestive heart failure [CHF]) or as composite outcomes (CVD or major adverse cardiovascular events [MACE]). Proportional rate models and conditional models assessed associations between risk factors and CVD outcomes., Results: Over a median follow-up of 29 years, 239 participants had 421 CVD events, and 120 individuals had 149 MACE. Age was the strongest risk factor for acute MI, silent MI, stroke, and PTCA/CABG, while glycemia was the strongest risk factor for CVD death, CHF, and angina, second strongest for acute MI and PTCA/CABG, third strongest for stroke, and not associated with silent MI. HbA 1c was the strongest modifiable risk factor for a first CVD event (CVD: HR 1.38 [95% CI 1.21, 1.56] per 1% higher HbA 1c ; MACE: HR 1.54 [1.30, 1.82]) and also for subsequent CVD events (CVD: incidence ratio [IR] 1.28 [95% CI 1.09, 1.51]; MACE: IR 1.89 [1.36, 2.61])., Conclusions: Intensive glycemic management is recommended to lower the risk of initial CVD events in T1D. After a first event, optimal glycemic control may reduce the risk of recurrent CVD events and should be maintained., (© 2020 by the American Diabetes Association.)

Immune complexes (IC) containing predominantly malondialdehyde-LDL and the corresponding autoantibodies (MDA-LDL IC) predict acute cardiovascular events, while IC rich in oxidized LDL (oxLDL IC) predict cardiovascular disease progression. Our objective was to determine mechanisms that could explain these prognostic differences. We compared the effects of the interaction of oxLDL, MDA-LDL and the corresponding IC with human macrophages focusing on apoptosis, metalloproteinases, and proinflammatory cytokines. MDA-LDL IC induced higher degrees of apoptosis, higher levels of caspase-3 expression, and increased expression and release of MMP-1 and TNF compared to MDA-LDL, oxLDL, and oxLDL IC. The pro-apoptotic effects of MDA-LDL IC were inhibited by blocking TNFR 1 or FcγRI. Blocking FcγRI abrogated the induction and expression of MMPs and proinflammatory cytokines by MDA-LDL IC. In conclusion, the interaction of MDA-LDL IC with FcγRI triggers macrophage apoptosis and increased expression and release of TNF and MMP-1, which can lead to the rupture of unstable plaques., (Copyright © 2017. Published by Elsevier Inc.)

Aims/hypothesis: Haptoglobin(Hp) 2-2 genotype has been shown to increase coronary artery disease (CAD) risk in numerous type 2 diabetes studies but in only one type 1 diabetes cohort. We assessed the association of Hp2-2 with incident CAD over 26years of follow-up in 1303 Caucasian participants of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study., Methods: DCCT randomized volunteers with type 1 diabetes to intensive versus conventional therapy within two cohorts: 'primary prevention' with 1-5years diabetes duration and 'secondary intervention' with 1-15years diabetes duration and early retinopathy, with or without albuminuria, but no advanced complications. CAD was defined as myocardial infarction (MI) or death judged to be from CAD, silent MI, angina, coronary revascularization, or congestive heart failure due to CAD., Results: In the entire DCCTcohort, Hp2-2 was not significantly associated with incident CAD or MI. However, in pre-specified exploratory subgroup analyses, an increased MI risk was suggested in the secondary cohort for those with Hp2-2., Conclusions/interpretation: The analysis does not statistically confirm an overall association between Hp 2-2 and incident CAD, however, some suggestions of associations were observed in secondary analyses., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The hypothesis that plasma prekallikrein (PK) is a risk factor for the development of vascular complications was assessed in a study using the Diabetes Control and Complications Trial (DCCT)/Epidemiology and Diabetes Interventions and Complications (EDIC) cohort of subjects with type 1 diabetes. The circulating levels of plasma PK activity were measured in the plasma of 636 subjects with type 1 diabetes (EDIC years 3-5). Common and internal carotid intima-media thickness (IMT) were measured by B-mode ultrasonography in EDIC years 1 and 6. Plasma PK levels were positively and significantly associated with BMI, hemoglobin A1c, systolic blood pressure, total cholesterol, LDL cholesterol, and triglycerides but not with age, sex, duration of diabetes, or HDL cholesterol. Univariate and multivariable statistical models after controlling for other risk factors consistently demonstrated a positive association between plasma PK and progression of internal carotid IMT. Multivariate analysis using a general linear model showed plasma PK to be significantly associated with progression of both internal and combined IMT (Wilks Λ P value of 0.005). In addition, the mean internal carotid IMT levels were higher in subjects with plasma PK levels in the highest 10th percentile compared with subjects with plasma PK levels in the lower 10th percentile (P = 0.048). These novel findings implicate plasma PK as a risk factor for vascular disease in type 1 diabetes., (© 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)

Aims: The VADT was a randomized clinical trial designed to assess the effect of intensive vs. standard glucose management on cardiovascular events in Type 2 diabetes. At the end of the study, intensive management failed to improve outcomes. We performed plasma lipoprotein subclass analyses to yield new information on the effects of study randomization on cardiovascular risk., Methods: This is a cross-sectional study of a subset of the VADT (740 men: 368 intensive; 372 standard), conducted at least six months (mean±SD: 2.1±0.8years) post-randomization. Conventional lipids, apolipoprotein-defined (ADLS) lipoprotein subclasses, ApoCIII, ApoE, and Nuclear Magnetic Resonance (NMR) lipoprotein subclasses were determined., Results: In intensive vs. standard groups, conventional lipids and ADLS did not differ significantly. However, with intensive treatment, NMR-determined large and medium VLDL subclasses and VLDL diameter were lower, LDL diameter was higher, medium HDL was higher, and small HDL was lower (all p<0.05). Also, ApoCIII levels were lower (p<0.01)., Conclusions: In a subset of diabetic men from the VADT, intensive glucose management did not affect conventional lipids or ADLS, but had some beneficial effects on particle characteristics as defined by NMR and on ApoCIII., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Aims: Dyslipoproteinemia has been associated with nephropathy in diabetes, with stronger correlations in men than in women. We aimed to characterize and compare plasma lipoprotein profiles associated with normal and increased albuminuria in men and women using apolipoprotein-defined lipoprotein subclasses and simple apolipoprotein measures., Methods: This is a cross-sectional study in a subset (154 women and 282 men) of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort, using samples obtained in 1997-9. Immunochemical methods were used to quantify plasma apolipoprotein-based lipoprotein subclasses and individual apolipoprotein levels., Results: In adjusted analyses, elevated Lipoprotein-B (Lp-B) was significantly associated with macroalbuminuria in men [odds ratios (OR) and 95% confidence interval (CI): 2.13 (1.15-3.97)] and women [3.01 (1.11-8.12)], while association with Lp-B:C was observed only in men [1.84 (1.19-2.86)]. For individual apolipoproteins the following significant associations with macroalbuminuria were observed in men only: Apolipoprotein B (ApoB) [1.97 (1.20-3.25)], Apo-AII [0.52 (0.29-0.93)], ApoC-III [1.95 (1.16-3.30)], "ApoC-III in VLDL" (heparin-manganese precipitate) [1.88 (1.16-3.04)], and "ApoCIII in HDL" (heparin-manganese supernatant) [2.03 (1.27-3.26)], all P<0.05)., Conclusions: Atherogenic apolipoprotein-based profiles are associated with nephropathy in Type 1 diabetic men and to a lesser extent in women. The difference could result from the greater prevalence and severity of dyslipoproteinemia, and from the greater prevalence of renal dysfunction, in men vs women., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Demographic factors such as race, vital status, gender, and age could affect the final renal outcome of patients who undergo renal transplantation. These demographic factors could be assessed at the recipient and donor levels. Repeated measures for blood urea nitrogen (BUN) are typically recorded for each patient following renal transplantation, as a biomarker to assess renal progress. However, once a patient develops renal failure due to graft rejection, no measurement of BUN can be registered and the patient goes back to dialysis. This causes loss of follow-up and incomplete data on BUN measurements, a problem referred to as informative right censoring. If this problem is ignored, inaccurate, and biased estimates will be generated. In this study, unbiased estimates for the rate of change of BUN levels over time adjusted for informative right censoring and demographic factors were acquired using a sophisticated model of analysis. Our results demonstrated that BUN levels for Caucasians were decreasing at a greater rate than African Americans (p < 0.0001). When donors are deceased, African American recipients showed an increase instead of a decrease in their BUN levels following transplantation. Moreover, African Americans showed a decrease in their BUN levels when the donors were African Americans compared with when donors were Caucasians (p = 0.03). Our results also showed that BUN levels were decreasing at a greater rate when donors and recipients were of different gender than when they were of the same gender (p = 0.009). These results suggest that the success of renal transplantation is impacted by the donor/recipient demographic factors.

BACKGROUND The evidence for genetic susceptibility in the pathogenesis of diabetic nephropathy is well recognised, but the genes involved remain to be identified. It is hypothesised that mutations within the gene encoding connective tissue growth factor (CTGF/CCN2) will increase the propensity of diabetic subjects to develop nephropathy. METHODS AND RESULTS Genomic screening was performed for single nucleotide polymorphisms (SNPs) within the CTGF gene in 862 subjects from the DCCT/EDIC cohort of type 1 diabetes. A novel SNP was identified in the promoter region that changes a C-G at the position -20. The frequency of GG genotype in microalbuminuric patients (albumin excretion rate (AER) >40 mg/24 h) is significantly greater than diabetics with AER <40 mg/24 h, p<0.0001. The relative risk (RR) to develop microalbuminuria in diabetic subjects with the polymorphism is 3X higher than diabetic subjects without the polymorphism (RR 3.142, 95% CI 1.9238 to 5.1249; p<0.05). Kaplan-Meier survival curves demonstrated that the GG genotype group developed microalbuminuria and macroalbuminuria at a more rapid rate than the GC or CC genotypes. Functional studies demonstrated that the basal activity of the substituted allele/promoter (-20 GG allele) was significantly greater than that of the wild type promoter (-20 CC genotype). This higher level of basal activity of substituted allele CTGF/CCN2 promoter was abrogated upon suppression of Smad1 levels, indicating that SNP region in the CTGF/CCN2 promoter plays a vital role in the gene expression. CONCLUSIONS These findings provide the first evidence that variants within the promoter region of the CTGF/CCN2 gene predisposes diabetic subjects to develop albuminuria and demonstrate that Smad1 [corrected] controls the expression of CTGF/CCN2 promoter through this region.

Objective: We explored the relevance and significance of connective tissue growth factor (CTGF) as a determinant of renal and vascular complications among type 1 diabetic patients., Methods and Results: We measured the circulating and urinary levels of CTGF and CTGF N fragment in 1050 subjects with type 1 diabetes from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study cohort. We found that hypertensive diabetic subjects have significantly higher levels of plasma log CTGF N fragment relative to normotensive subjects (P = 0.0005). Multiple regression analysis showed a positive and independent association between CTGF N fragment levels and log albumin excretion rate (P < 0.0001). In categorical analysis, patients with macroalbuminuria had higher levels of CTGF N fragment than diabetic subjects with or without microalbuminuria (P < 0.0001). Univariate and multiple regression analyses demonstrated an independent and significant association of log CTGF N fragment with the common and internal carotid intima-media thickness. The relative risk for increased carotid intima-media thickness was higher in patients with concomitantly elevated plasma CTGF N fragment and macroalbuminuria relative to patients with normal plasma CTGF N fragment and normal albuminuria (relative risk = 4.76; 95% confidence interval, 2.21-10.25; P < 0.0001)., Conclusion: These findings demonstrate that plasma CTGF is a risk marker of diabetic renal and vascular disease.

Cardiovascular disease is a major cause of morbidity and premature mortality in diabetes. HDL plays an important role in limiting vascular damage by removing cholesterol and cholesteryl ester hydroperoxides from oxidized low density lipoprotein and foam cells. Methionine (Met) residues in apolipoprotein A-I (apoA-I), the major apolipoprotein of HDL, reduce peroxides in HDL lipids, forming methionine sulfoxide [Met(O)]. We examined the extent and sites of Met(O) formation in apoA-I of HDL isolated from plasma of healthy control and type 1 diabetic subjects to assess apoA-I exposure to lipid peroxides and the status of oxidative stress in the vascular compartment in diabetes. Three tryptic peptides of apoA-I contain Met residues: Q(84)-M(86)-K(88), W(108)-M(112)-R(116), and L(144)-M(148)-R(149). These peptides and their Met(O) analogs were identified and quantified by mass spectrometry. Relative to controls, Met(O) formation was significantly increased at all three locations (Met(86), Met(112), and Met(148)) in diabetic patients. The increase in Met(O) in the diabetic group did not correlate with other biomarkers of oxidative stress, such as N(epsilon)-malondialdehyde-lysine or N(epsilon)-(carboxymethyl)lysine, in plasma or lipoproteins. The higher Met(O) content in apoA-I from diabetic patients is consistent with increased levels of lipid peroxidation products in plasma in diabetes. Using the methods developed here, future studies can address the relationship between Met(O) in apoA-I and the risk, development, or progression of the vascular complications of diabetes.

Aims: To relate nuclear magnetic resonance lipoprotein subclass profiles (NMR-LSP) and other lipoprotein-related factors with carotid intima-media thickness (IMT) in Type 1 diabetes., Methods: Lipoprotein-related factors were determined in sera (obtained in 1997-1999) from 428 female [age 39 +/- 7 years (mean +/- SD)] and 540 male (age 40 +/- 7 years) Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) participants. NMR quantifies chylomicrons, three very low-density lipoprotein (VLDL) subclasses, intermediate density lipoprotein (IDL), three low-density lipoprotein (LDL) subclasses, two high-density lipoprotein (HDL) subclasses, mean VLDL, LDL and HDL size, and LDL particle concentration. Conventional lipids, ApoA1, ApoB and Lp(a) and in vitro LDL oxidizibility were also measured. IMT was determined (in 1994-1995) using high-resolution B-mode ultrasound. Relationships between IMT and lipoproteins were analysed by multiple linear regression, controlling for age, diabetes-related factors, and cardiovascular disease (CVD) risk factors., Results: IMT associations with lipoproteins were stronger for the internal than the common carotid artery, predominantly involving LDL. Internal carotid IMT was positively (P < 0.05) associated with NMR-based LDL subclasses and particle concentration, and with conventional LDL-cholesterol and ApoB in both genders. Common carotid IMT was associated, in men only, with large VLDL, IDL, conventional LDL cholesterol and ApoB., Conclusions: NMR-LSP reveals significant associations with carotid IMT in Type 1 diabetic patients, even 4 years after IMT measurement. NMR-LSP may aid early identification of high-risk diabetic patients and facilitate monitoring of interventions. Longer DCCT/EDIC cohort follow-up will yield CVD events and IMT progression, permitting more accurate assessment of pre-morbid lipoprotein profiles as determinants of cardiovascular risk in Type 1 diabetes.

Background: Predictors of diabetic nephropathy are only partly known and traditional risk factors do not adequately explain disease risk. We thus examined novel risk factors for overt nephropathy (ON) in type 1 diabetes., Methods: The EDC is a prospective study of childhood-onset type 1 diabetes. When first seen (1986-1988), mean age was 28 and diabetes duration 19 years. In the subsequent 10 years, 56 of 485 subjects without ON in 1986-88 developed ON. An age, duration (+/-3 years), and sex-matched control was identified for 47 cases. Forty-two matched pairs had available stored plasma samples obtained prior to ON onset in cases, and complete standard risk factor data., Results: Cases had a higher baseline albumin excretion rate (AER), HbA1, pulse rate, non-HDL cholesterol, fibrinogen, small LDL and lower eGDR and LDL particle size compared to controls (all P values<0.05). Multiple measures of immune complexes were increased in cases (P<0.05), whereas borderline elevations were seen for total antioxidant reserve (P=0.06) and retinol (P=0.08). Multivariably, other than AER, LDL particle size and IgG-IC were predictive beyond the standard predictors., Conclusion: Besides AER, the immunecomplexes and lipoprotein subclasses may provide additional information in the assessment of ON risk in type 1 diabetes.

Chronic endothelial infection is believed to be one of the factors able to cause endothelial cell damage and trigger the onset of human atherosclerosis. Chlamydophila pneumoniae infects endothelial cells and has received special attention because of both epidemiological and experimental evidence supporting its role as a risk factor for atherosclerosis. It is also possible that otherwise independent risk factors for atherosclerosis may have synergistic effects. Immune phenomena, such as the formation of circulating immune complexes (IC) containing modified LDL and corresponding antibodies, have been linked to the development of coronary artery disease. The antibodies involved in the immune response to modified lipoproteins are predominantly of the pro-inflammatory IgG1 and IgG3 subclasses. However, it is difficult to understand how circulating IC could cause endothelial damage and initiate the atherosclerotic process, unless they were formed in the subendothelial space or immobilized by endothelial cells. The last hypothesis would be possible if endothelial cells expressed Fcgamma receptors. Healthy endothelial cells do not express Fcgamma receptors, but endothelial cells infected by a variety of infectious agents do. Thus we decided to investigate whether infection of endothelial cells with C. pneumoniae is also able to cause the expression of Fcgamma receptors. The expression of Fcgamma receptors (CD64, 32, and 16) on human aortic endothelial cells infected with C. pneumoniae for 4, 24, 36, and 48 h was studied by flow cytometry. Twenty-four hours after infection 30-40% of the endothelial cells had detectable inclusion bodies, 8-9% of the total number of cells (approximately 25% of the infected cells) expressed FcgammaRII, and about 1.5-2% (5% of infected cells) expressed FcgammaRI and FcgammaRIII. Double-staining studies confirmed that the expression of FcgammaRII was limited to C. pneumoniae-infected endothelial cells. We conclude that C. pneumoniae infection induces primarily the expression of FcgammaRII by endothelial cells and this may be a significant link between two proposed pathogenic mechanisms involved in the pathogenesis of human atherosclerosis.

The goal of this study was to characterize the isotypes and reactivity of human autoantibodies to copper oxidized LDL (oxLDL). Forty-six purified oxLDL antibodies contained immunoglobulins of the three major isotypes, with a predominance of IgG, subclasses 1 and 3. These IgG isotypes are known to interact with FcRgammaI and to activate the complement system and thus are potentially able to activate macrophages and cause foam cell formation. The same purified antibodies were tested for cross-reactivity with malondialdehyde (MDA)-, glycated (Glyc)-, and native (n)LDL and cardiolipin. Absorption with oxLDL resulted in a decrease of reactivity of 77.2 +/- 4.7%. Absorption with MDA-LDL resulted in a wider range of reduction of reactivity values, ranging from 50 to 87%, possibly reflecting differences in the degree of MDA modification. Absorption with Glyc- and nLDL caused a minor decrease in the reactivity of antibodies to oxLDL (5.9 +/- 7.1 and 6.8 +/- 6. 4%, respectively), comparable to the reduction of reactivity (2.1 +/- 4.0%) measured after absorption with transferrin, an irrelevant protein used as a negative control. These results suggest that oxLDL antibodies recognize primarily MDA epitopes. To determine whether purified oxLDL antibodies also recognize other epitopes known to be generated during copper oxidation of LDL, such as 4-hydroxynonenal (HNE)- and N(epsilon)(carboxymethyl)-lysine (CML), two additional sets of experiments were carried out. First, we monitored the formation of CML-, MDA-lysine, and HNE-lysine at different times during copper oxidation of two LDL pools. Both pools showed simultaneous increases in protein modification, as indicated by increasing fluorescence emission at 430 nm, and in immunoreactivity with oxLDL antibodies, coinciding closely with MDA modification of lysine groups. Second, we assessed whether the reactivity of oxLDL antibodies could be blocked by absorption with CML- or HNE-LDL. HNE-LDL did not react with isolated oxLDL antibodies. Highly modified CML-LDL (>90% of lysine residues modified) reduced the reactivity of oxLDL antibodies, but only by 25.5%. Finally, we investigated the possible cross-reactivity of oxLDL antibodies with cardiolipin. Seventeen purified oxLDL antibodies were used in this study, which showed that absorption with oxLDL or nLDL did not affect their reactivity with immobilized cardiolipin., (Copyright 2000 Academic Press.)

Background: Small apolipoprotein A (apo [A]) phenotypes and oxidized low-density lipoprotein immune complexes (oxLDL-ICs) are known to be associated with the development of atherosclerosis in adults. Presence of these factors in children and their relationships with other known cardiovascular risk factors have not been well documented., Objective: To examine the relationship of oxLDL-ICs with apo(A) phenotypes and other known cardiovascular risk factors in children., Design: A survey of asymptomatic 9- to 11-year-old children, randomly selected from a cohort of children stratified based on family history of premature coronary artery disease., Setting: A preventive medicine research institute., Participants: Thirty-five children with or without a family history of premature coronary artery disease who are participating in a longitudinal cardiovascular health study., Main Outcome Measures: The influence of apo(A) phenotypes on plasma levels of oxLDL-ICs after controlling for lipid/lipoprotein levels, percentage of body fat, and physical fitness., Results: Oxidized low-density lipoprotein immune complexes were significantly correlated with the levels of total cholesterol (r = 0.56, P< or =.05), low-density lipoprotein cholesterol (r = 0.64, P< or =.01), and low-density lipoprotein cholesterol/high-density lipoprotein cholesterol (r = 0.54, P<.05). Oxidized low-density lipoprotein immune complexes were also correlated with total cholesterol high-density lipoprotein cholesterol (r = 0.49, P< or =.06) and percentage of body fat (r = 0.48, P< or =.06). However, they achieved only a borderline level of statistical significance after adjustment for multiple comparisons. Multiple regression analysis demonstrated that small apo(A) phenotypes, levels of low-density lipoprotein cholesterol, and family history of premature coronary artery disease explained 54% of the variation of oxLDL-ICs using a parsimonious model (P = .001)., Conclusions: Significant correlations exist between oxLDL-ICs and known cardiovascular risk factors in children. The association of oxLDL-ICs with the genetically controlled small apo(A) phenotype suggests that the genetic predisposition to immune complex formation may be an important determinant of future coronary artery disease.

Medical investigators in South Carolina have been on the "cutting edge" of diabetes research for a number of decades. Despite this fact, our state ranks second in the nation in diabetes prevalence, and diabetes complications are more severe here than anywhere else. It is from the efforts of these investigators that our hope for a brighter future comes. Through a concerted effort toward prevention, improvements in care, and investigation of the pathophysiology of diabetes and its complications, researchers may reduce the substantial burden of diabetes in our state and throughout the world.

We have studied the effects of dietary supplementation with fish oil on immunological parameters in a group of six normal volunteers, four of whom received a fish oil extract (total EPA dose of 2.4 g/day, which is on the lower range of clinically effective doses) for 6 weeks and two of which received a placebo (olive oil) for an identical period of time. Each volunteer was followed up for a period of 23 weeks after the dietary intervention was ended. All volunteers were boosted with tetanus toxoid (TT) at the onset of the trial. Several immune parameters were followed longitudinally, including NBT reduction and lysozyme release to test neutrophil function; lymphocyte subpopulations; mitogenic responses to phytohemagglutinin (PHA), concanavalin A (Con A) and anti-CD3; IL-2 release after PHA and pokeweed mitogen (PWM) stimulation; immunoglobulin and anti-TT antibody (ATT) synthesis by stimulated lymphocytes; and serum levels of immunoglobulins and of ATT. No consistent changes were observed in neutrophil function tests, mitogenic responses to PHA and Con A, and lymphocyte subsets. The mitogenic response to anti-CD3 and the release of IL-2 after stimulation with PHA and PWM appeared reduced as a consequence of fish oil ingestion, and levels of serum immunoglobulins decreased in three of the volunteers receiving fish oil supplementation. The systemic humoral response after the TT booster appeared not to be influenced by the ingestion of fish oil. However, in those subjects who were given fish oil supplementation, the specific in vitro response of their peripheral blood lymphocytes to TT appeared to be compromised at Week 3. This could reflect the need for progressive accumulation of EPA in lymphocyte membranes for the suppressive effect to be detectable, but it could also reflect a differential sensitivity to the effects of fish oil of circulating B lymphocytes vs. bone marrow B lymphocytes. All the parameters apparently affected by fish oil ingestion were also affected by the incubation of normal lymphocytes with EPA in vitro. In conclusion, low doses of fish oil may have a mild immunosuppressive effect affecting both T and B cell functions. These observations stress the need for more extensive trials designed to determine whether immunosuppressive effects can be consistently elicited and for studies aimed at determining the mechanisms by which omega-3 fatty acids affect the immune system.

Patients with diabetes mellitus manifest increased in vitro platelet aggregation and increased synthesis of the proaggregant and vasoconstrictor, thromboxane A2 (TXA2). We studied the effects of continuous insulin infusion treatment on platelet aggregation and arachidonic acid (AA)-stimulated platelet TXA2 synthesis (15 and 30 s post-AA, 1 mM) in 16 type I diabetic patients. Strict glycemic control was induced with the Biostator for 2 days and maintained for 12-14 days with continuous subcutaneous insulin infusion (CSII). The average premeal plasma glucose level (4/day) fell from 184 +/- 15, before treatment, to 107 +/- 6 mg/dl on the final day (P less than 0.001). After control, platelet synthesis of TXA2, measured by radioimmunoassay of its stable metabolite, immunoreactive TXB2 (iTXB2), decreased in all patients (30 s: 276 +/- 31 versus 199 +/- 28 ng iTXB2/ml/5 X 10(5) platelets; P less than 0.05). The reduction in platelet iTXB2 synthesis (15 and 30 s) was greater in poorly controlled patients (HbA1c greater than 12%; N = 8), and for all patients the decrease in iTXB2 (15 and 30 s) was correlated with the prestudy HbA1c level (15 s: r = 0.6; P less than 0.01). In contrast, platelet aggregation responses did not improve during intensive insulin treatment. The ED50 for AA (dose producing 50% maximum aggregation at 1 min) was unchanged after 2 wk of treatment and the ED50 for aggregation induced by ADP fell significantly in patients with HbA1c greater than 12% (2.8 +/- 1.3 versus 1.2 +/- 0.6 microM; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum lipids and lipoproteins and urinary apolipoprotein A (Apo A) were determined in two groups of patients. One group consisted of 11 children (ages ranging from 4 to 14 years) with minimal change glomerular disease. The other group consisted of 13 patients, eight less than 19 years old five adults, with different types of chronic glomerulopathy. Elimination of urinary lysozyme was a feature of chronic glomerulopathies, and creatinine clearances were also significantly lower in this group. Patients with chronic glomerulopathies had significantly lower HDL cholesterol and Apo A concentrations in their sera. In contrast, urinary Apo A concentrations were significantly higher in patients with chronic glomerulopathies, who also showed significantly lower urinary protein selectivities. Lipoprotein electrophoresis of urines containing Apo A showed distinct high-density lipoprotein (HDL) fractions, suggesting that HDL is eliminated in the urine as a result of increased glomerular permeability. This is also supported by a correlation coefficient of 0.77 between the selectivity indices and the ratio of urinary Apo A to total proteinuria. The determination of urinary Apo A appears to give valuable diagnostic information in patients with glomerular disease. According to our results the absence of urinary Apo A is very suggestive of minimal change glomerular disease.

Numerous studies have shown that patients with diabetes mellitus have accelerated atherosclerotic vascular disease, and major advances in understanding it pathogenesis have been made. Current suggestions are that endothelial injury may be the initial event in the genesis of atherosclerosis, followed by platelet adhesion and aggregation at the site of injury. In diabetes, evidence of endothelial dysfunction is present. Smooth muscle cell proliferation is an important pathologic finding in atherosclerosis. This process is stimulated by a platelet mitogen, which has been partially characterized. The mitogen has not been studied in diabetes. Lipid accumulation in the area of the atherosclerotic lesion is primarily in the form of intracellular and extracellular esterified cholesterol. In uncontrolled diabetes, elevated plasma low density lipoprotein levels and decreased plasma high density lipoprotein levels favor lipid deposition in large vessels. There is evidence of a thrombotic state in certain diabetic patients. Collectively, these abnormalities of endothelial, platelet, smooth muscle, lipoprotein, and coagulation behavior may be viewed as contributing to the problem of accelerated atherosclerosis in diabetes. A thorough understanding of the pathogenesis of this process aids in designing appropriate preventive therapeutic approaches.

Diabetes mellitus is associated with altered platelet function and endothelial damage, but their relationship remains unclear. We examined the effect of short-term metabolic control with insulin in 14- and 28-day streptozocin-induced diabetic rats on alterations in in vitro platelet aggregation and serotonin release. Endothelial damage was assessed by plasma concentrations of von Willebrand factor activity (VIIIR:WF) and factor VIII-related antigen (VIIIR:Ag). Insulin was administered for 5 or 7 days at 9 or 21 days, respectively, after streptozocin. Enhanced platelet aggregation responses to adenosine diphosphate (ADP) and thrombin occurred after both durations of diabetes. Insulin therapy returned ADP-induced, but not thrombin-induced, responses to normal. Enhanced thrombin-induced platelet release of serotonin occurred at both times. Collagen-induced platelet release was enhanced in 28-day diabetic rats. Insulin therapy returned these responses to normal. Plasma concentrations of VIIIR:WF and VIIIR:Ag were elevated in 28-day, but only VIIIR:WF was elevated in 14-day diabetic rats. Insulin therapy reduced the elevated levels of VIIIR:Ag in 28-day diabetic rats, but had little effect on either parameter after the shorter duration of diabetes. In summary, Enhanced platelet aggregation and increased release of serotonin occur shortly after the induction of diabetes by streptozocin in adult rats. These platelet changes precede alterations of endothelial function, as determined by plasma VIIIR:WF and VIIIR:Ag levels. Platelet changes respond more rapidly to insulin therapy than do endothelial changes in diabetic rats. The duration of diabetes before insulin therapy does not affect these relationships.(ABSTRACT TRUNCATED AT 250 WORDS)

The association of atherosclerosis with lipoprotein disorders is well recognized. Since lipoprotein abnormalities are present in diabetes mellitus, it has been postulated that these abnormalities may constitute a link between diabetes and the accelerated atherogenesis that usually accompanies this disease. The quantitative alterations in lipoproteins are, however, relatively small to be solely responsible for the accelerated atherosclerosis present in diabetes. Other possible explanations have been thought. One of the most attractive hypotheses postulates that the biochemical abnormalities existent in diabetes could lead to the formation of lipoproteins with an abnormal composition and that lipoproteins so formed could interact abnormally with cells and be more atherogenic. We present data showing that the internalization and degradation by cultured fibroblasts of LDL isolated from diabetic patients in poor metabolic control is significantly decreased and that this decrease is further enhanced when the cells are incubated with lipoprotein depleted serum isolated from diabetic patients in poor metabolic control. We discussed several alterations in LDL composition and diabetic serum that may be responsible for the abnormal interaction between cultured cells and LDL isolated from diabetic patients. The relevance of these abnormal cell-LDL interactions in the development of atherosclerosis in diabetes mellitus is also discussed.

New concepts about the pathogenesis of atherosclerosis in diabetes mellitus are presented. Emphasis is given to alterations of endothelial function, as indicated by von Willebrand factor activity, prostacyclin release, and fibrinolytic activity in diabetes mellitus. Previous work on platelet aggregation and arachidonic acid metabolism is updated and recent findings are emphasized. The atherogenic mix of elevated low-density lipoprotein cholesterol and low high-density lipoprotein cholesterol levels in uncontrolled diabetes mellitus is noted. The lipid hypothesis is extended by consideration of very low-density lipoprotein and intermediate-density lipoprotein metabolism in diabetes. Lipoprotein-cell interactions that may contribute to atherosclerosis are reviewed and suggestions are made for future research in order to clarify the pathogenesis of atherosclerosis in diabetes mellitus.

The relationship between platelet abnormalities and vessel wall changes in diabetes is not known. We have examined the time course of alterations in in vitro platelet function and endothelial damage, as assessed by measurement of plasma levels of von Willebrand factor (VIIIR:WF) and factor VIII-related antigen (VIIIR:Ag), in streptozotocin-induced diabetic rats. Platelet aggregation and the platelet release reaction in response to ADP, thrombin, and collagen were measured in suspensions of washed platelets prepared from rats 3, 7, 14, or 28 days after induction of diabetes and in control animals. Platelets from diabetic animals showed enhanced aggregation response to ADP as early as 3 days after induction of diabetes and became hyperresponsive to thrombin after 7 days, compared to control platelets. Thrombin-induced release of serotonin was greater in platelets from diabetic animals at 14 days. Collagen-induced responses were not different at any time studied. VIIIR:WF was determined by ristocetin-induced platelet agglutination time in gel-filtered platelets, and VIIIR:Ag was determined by immunoelectrophoretic technique. VIIIR:WF and VIIIR:Ag were significantly enhanced in plasma from rats at 28 days after induction of diabetes and VIIIR:Ag was enhanced in plasma from rats at 14 days after induction of diabetes, but at the earlier times studied, neither were different from values in plasma from control-treated rats. Changes in VIIIR:WF and VIIIR:Ag therefore occurred later than the changes in platelet function. Plasma cholesterol concentrations were not significantly different at any of the times studied, but plasma triglyceride concentrations were significantly increased at 3 days and remained increased with further durations of diabetes. This may have contributed to the observed platelet and vessel wall changes. If these in vitro alterations reflect in vivo behavior, then platelet alterations occur before vessel wall changes and therefore do not appear to be a consequence of such changes in experimental diabetes mellitus.