Apo C subclasses from non-insulin-dependent diabetic patients--a quantitative comparison with control subjects

Longitudinal association between egg consumption and the risk of cardiovascular disease: interaction with type 2 diabetes mellitus

Background/objectives

It remains unclear if high egg consumption has beneficial or adverse effects on cardiometabolic health. The present study prospectively evaluated the longitudinal association between egg-consumption levels and incident cardiovascular disease (CVD) among Korean adults.

Subjects/methods

We conducted a prospective cohort study of 9248 Korean adults aged 40–69 years without CVD or cancer at the baseline from the Korean Genome and Epidemiology Study, Ansung–Ansan cohort, South Korea. The egg intake of the participants was estimated using a validated semiquantitative food frequency questionnaire at the baseline and the second follow-up examination and categorized into quartiles. CVD cases were identified using biennial questionnaires and confirmed through repeated in-depth personal interviews. Hazard ratios (HR) and 95% confidence interval (CI) were analyzed using Cox proportional hazard regression.

Results

During the average follow-up of 7.3 years, 570 cases of CVD were newly diagnosed. After adjusting for multiple confounding variables, egg-intake levels were not associated with CVD incidence (HR: 1.14, 95% CI: 0.87–1.49, P for trend: 0.7). However, the association was modified by type 2 diabetes mellitus (T2DM) status. Egg consumption was significantly associated with an increased risk for incident CVD among participants with T2DM; individuals with the highest egg intake (4.2 ± 0.04 eggs/week) had a 2.8 times higher incidence of CVD (HR: 2.81, 95% CI: 1.25–6.30, P for trend: 0.02) than those with the lowest egg intake (0.1 ± 0.02 eggs/week). However, no association was observed among individuals without T2DM (HR: 1.03, 95% CI: 0.77–1.38, P for trend: 0.8).

Conclusions

Higher egg consumption may increase the risk for CVD in Korean patients with T2DM. Our findings provide a basis for the development of an optimal dietary cholesterol intake guideline for the Korean population.

Egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies

OBJECTIVE

To investigate and quantify the potential dose-response association between egg consumption and risk of coronary heart disease and stroke.

DESIGN

Dose-response meta-analysis of prospective cohort studies.

DATA SOURCES

PubMed and Embase prior to June 2012 and references of relevant original papers and review articles.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective cohort studies with relative risks and 95% confidence intervals of coronary heart disease or stroke for three or more categories of egg consumption.

RESULTS

Eight articles with 17 reports (nine for coronary heart disease, eight for stroke) were eligible for inclusion in the meta-analysis (3,081,269 person years and 5847 incident cases for coronary heart disease, and 4,148,095 person years and 7579 incident cases for stroke). No evidence of a curve linear association was seen between egg consumption and risk of coronary heart disease or stroke (P=0.67 and P=0.27 for non-linearity, respectively). The summary relative risk of coronary heart disease for an increase of one egg consumed per day was 0.99 (95% confidence interval 0.85 to 1.15; P=0.88 for linear trend) without heterogeneity among studies (P=0.97, I(2)=0%). For stroke, the combined relative risk for an increase of one egg consumed per day was 0.91 (0.81 to 1.02; P=0.10 for linear trend) without heterogeneity among studies (P=0.46, I(2)=0%). In a subgroup analysis of diabetic populations, the relative risk of coronary heart disease comparing the highest with the lowest egg consumption was 1.54 (1.14 to 2.09; P=0.01). In addition, people with higher egg consumption had a 25% (0.57 to 0.99; P=0.04) lower risk of developing hemorrhagic stroke.

CONCLUSIONS

Higher consumption of eggs (up to one egg per day) is not associated with increased risk of coronary heart disease or stroke. The increased risk of coronary heart disease among diabetic patients and reduced risk of hemorrhagic stroke associated with higher egg consumption in subgroup analyses warrant further studies.

Parallel increase of plasma apoproteins C-II and C-III in Type 2 diabetic patients

AIMS

To determine plasma levels of apoprotein (apo) C-II and apoprotein C-III in Type 2 diabetic patients and to examine the clinical and biological factors that are associated with elevated apoC concentrations.

METHODS

We measured apoC-II and apoC-III in total plasma and in non-high-density lipoprotein fractions by an immunoturbidimetric assay in 88 Caucasian Type 2 diabetic patients and in 138 healthy control subjects.

RESULTS

Plasma levels of both apoC-II and apoC-III were increased in Type 2 diabetic patients. The clinical conditions associated with an increase of plasma apoC-II and apoC-III were abdominal obesity, body mass index, poor glycaemic control and lack of insulin treatment. However, when multivariate analysis was used, plasma apoCs levels correlated with triglyceride levels only. The apoC-III/apoC-II ratio was similar in the Type 2 diabetic and control subjects.

CONCLUSIONS

Our study shows the parallel increase of apoC-II and C-III in Type 2 diabetic patients. This parallel increase is related to hypertriglyceridaemia only.

APOC3/A5 haplotypes, lipid levels, and risk of myocardial infarction in the Central Valley of Costa Rica

Genetic variation in the APOC3 and APOA5 genes has been associated with plasma triglyceride concentrations and may affect the risk of myocardial infarction (MI). To assess whether APOC3/A5 haplotypes are associated with risk of MI, we examined three single-nucleotide polymorphisms (SNPs) in APOC3 (3238C>G, -455T>C, and -482C>T) and six SNPs in the APOA5 gene (-1131T>C, c.-3A>G, c.56C>G, IVS3+476G>A, c.553G>T, and c.1259T>C) in incident cases (n = 1,703) of a first nonfatal MI matched for gender, age, and area of residence with population-based controls (n = 1,703). Conditional logistic regression models, adjusted for potential environmental confounders, were used for analysis. The common APOC3*222 haplotype was more frequent in cases than in controls (17.4% and 13.7%, respectively, P < 0.001) and was associated with increased risk of MI [odds ratio (OR) = 1.27; 95% confidence interval (95% CI), 1.09, 1.48] compared with APOC3*111 wild-type haplotype. This association was independent of the APOA5 SNPs. Although the APOC3 3238G, APOA5 -1131C, APOA5 c.-3G, and APOA5 c.1259C alleles were associated with higher triglyceride plasma concentrations, these effects could not explain the associations with MI in this population. In summary, this study supports the hypothesis that haplotypes in the APOC3 gene but not in the APOA5 gene increase susceptibility to MI.

Hypertriglyceridemia but not diabetes status is associated with VLDL containing apolipoprotein CIII in patients with coronary heart disease

High apoCIII concentration in apoB lipoproteins is a prominent component of atherogenic dyslipidemia, and explains the risk of coronary heart disease (CHD) associated with high triglyceride (TG). We hypothesized that diabetic people have atherogenic dyslipidemia with apoCIII in excess of that accounted for by their high TG levels. We selected 30 diabetic and 30 nondiabetic persons, 15 of each with fasting TG<160 mg/dl and 15 with TG>/=200 mg/dl. Using immunoaffinity chromatography and ultracentrifugation, we prepared large and small VLDL, IDL and LDL with or without apoCIII or apoE. The groups with TG>/=200 mg/dl, regardless of diabetes status, had higher concentrations of large and small VLDL particles with apoCIII and higher apoCIII concentrations than the groups with fasting TG<160 mg/dl. The diabetes groups did not have higher concentrations of these lipoproteins than the nondiabetes groups within the same fasting TG criteria. In conclusion, high concentrations of apoCIII-containing VLDL are associated with hypertriglyceridemia, which may play a critical role in identifying the high risk of CHD in hypertriglyceridemic patients whether diabetic or nondiabetic. Diabetes status per se does not appear to be associated with high concentrations of apoCIII-containing TG-rich lipoprotein particles, if the plasma TG levels are similar.