Plasma lipoprotein particle concentrations in postmenopausal women with unstable coronary artery disease. Analysis of diagnostic accuracy using receiver operating characteristics

Plasma levels of HDL subpopulations and remnant lipoproteins predict the extent of angiographically-defined coronary artery disease in postmenopausal women

OBJECTIVE

The association of coronary heart disease (CHD) with subpopulations of triglyceride (TG)-rich lipoproteins and high-density lipoproteins (HDL) is established in men, but has not been well characterized in women.

METHODS AND RESULTS

Plasma HDL subpopulation concentrations, quantified by 2-dimensional gel electrophoresis, and plasma remnant-like particle cholesterol (RLP-C) concentrations were measured in 256 postmenopausal women with established CHD and in 126 CHD-free postmenopausal women. Coronary artery disease was assessed in women with CHD by quantitative coronary angiography. Plasma RLP-C and prebeta1 HDL concentrations were higher and alpha1 and alpha2 HDL concentrations were lower in CHD than in CHD-free women. After adjustment for conventional CHD-risk factors, plasma levels of RLP-C were positively associated with the degree of coronary artery disease. In similar analyses, plasma prebeta1 HDL particle concentrations were positively associated and alpha2 HDL particle concentrations were inversely associated with the extent of coronary atherosclerosis. Plasma TG, low density lipoprotein cholesterol, and HDL cholesterol levels were not associated with the degree of coronary atherosclerosis.

CONCLUSIONS

The degree of coronary atherosclerosis in postmenopausal women is linked to a dysregulation of the TG/HDL metabolism. Subpopulations of TG-rich and HDL lipoproteins are better predictors of disease than TG and HDL cholesterol concentrations.

Improved identification of patients with coronary artery disease by the use of new lipid and lipoprotein biomarkers

Increasing attention is being directed toward new lipid and lipoprotein biomarkers as risk factors for coronary artery disease, although limited information is available on the diagnostic accuracy of these new biomarkers for the identification of patients with coronary artery disease. In the present study, levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, lipoprotein-associated phospholipase A2 (Lp-PLA2), and oxidized LDL/HDL cholesterol were determined in 431 apparently healthy men and women without clinical evidence of coronary artery disease who were matched for age and gender with 490 men and women with coronary artery disease who participated in the Second Fragmin and Fast Revascularization During Instability in Coronary Artery Disease (FRISC-II) trial. Diagnostic accuracy was determined by receiver-operating characteristic curve analysis by measuring the area under the curve. The diagnostic accuracies of each lipid or lipoprotein biomarker (in descending order of area under the curve) were 0.867 for oxidized LDL/HDL cholesterol (95% confidence interval [CI] 0.844 to 0.890), 0.826 for oxidized LDL (95% CI 0.800 to 0.852), 0.775 for 1/HDL cholesterol (95% CI 0.745 to 0.805), 0.764 for total/HDL cholesterol (95% CI 0.733 to 0.795), 0.631 for triglycerides (95% CI 0.594 to 0.667), 0.597 for Lp-PLA2 (95% CI 0.558 to 0.615), 0.577 for LDL cholesterol (95% CI 0.539 to 0.615), and 0.520 for total cholesterol (95% CI 0.482 to 0.537). In conclusion, these findings indicate that the ratio of oxidized LDL to HDL cholesterol was a more potent biomarker for discriminating between subjects with and without coronary artery disease than traditionally measured lipids and lipoproteins and Lp-PLA2.

Triglycerides + high-density-lipoprotein-cholesterol dyslipidaemia, a coronary risk factor in elderly women: the CArdiovascular STudy in the ELderly

BACKGROUND

The relationship between serum triglycerides (TG) level and the risk of coronary heart disease (CHD) mortality remains controversial.

AIMS

To evaluate whether TG level is a risk factor for CHD in elderly people from general population, and to look for interactions between TG and other risk factors.

METHODS

3257 subjects aged >or= 65 years followed up for 12 years from the CArdiovascular STudy in the ELderly. Blood tests and anthropometric measurements were performed. Continuous items were divided into quintiles and, for each quintile, adjusted hazard ratio (HR) with 95% confidence interval (CI) for CHD mortality was derived by genders from Cox analysis.

RESULTS

In women, the HR of being in the fifth rather than in the first quintile of TG was 2.45 (CI 1.48-3.51). In turn, high-density-lipoprotein cholesterol (HDL-C) inversely predicted CHD mortality; the HR of being in the first rather than in the fifth quintiles of HDL-C was 1.52 (CI 1.24-2.36). The risk of CHD mortality further increased up to 3.81 (CI 1.62-5.43) when high TG and low HDL-C were combined. No predictive role for either TG or HDL-C was detected in men.

CONCLUSIONS

TG and HDL-C were independent predictors of CHD mortality in elderly women. The combination high TG + low HDL-C quadrupled the risk of CHD mortality in this gender only.

Relation between age and gender differences in plasma triglyceride concentrations and coronary artery disease in Southern Turkey

BACKGROUND

Coronary artery disease (CAD) is still a leading cause of morbidity and mortality in both genders in Turkey as well as other countries. The role of plasma triglycerides (TG) as a CAD risk factor has been controversial. We investigated the relation between age and gender differences in plasma TG and CAD in patients with angiographically proven CAD.

METHODS

The study population consisted of 937 patients (605 males and 332 females, aged between 32 and 82 years). The patients were divided into three age groups as < 45, 45-59 and > or = 60 years. Risk factors were considered as hypertension, hyperlipidemia, diabetes mellitus, cigarette smoking and family history. Hypertriglyceridemia was defined as TG concentration > 150 mg/dl (> 1.69 mmol/l).

RESULTS

Of the total, 608 had CAD. TG was an independent risk factor for CAD only in women (p < 0.05). There was also a positive correlation between TG concentrations and number of the diseased vessels only in women (p = 0.001, r = 0.2).

CONCLUSION

High TG concentrations increase CAD risk more in women than in men in Southern Turkey. Triglycerides should be taken into consideration as an important risk factor especially in women > 45 years of age.

Fractional esterification rate of cholesterol and ratio of triglycerides to HDL-cholesterol are powerful predictors of positive findings on coronary angiography

BACKGROUND

We examined the predictive value of various clinical and biochemical markers for angiographically defined coronary artery disease (aCAD). Specifically, we assessed the value of the ratio of plasma triglyceride (TGs) to HDL-cholesterol (HDL-C) and the fractional esterification rate of cholesterol in plasma depleted of apolipoprotein B (apoB)-containing lipoproteins (FER(HDL)), a functional marker of HDL and LDL particle size.

METHODS

Patients (788 men and 320 women) undergoing coronary angiography were classified into groups with positive [aCAD(+)] and negative [aCAD(-)] findings. Patient age, body mass index, waist circumference, blood pressure (BP), medications, drinking, smoking, exercise habits, and plasma total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-unesterified cholesterol, HDL-C, TGs, FER(HDL), apoB, log(TG/HDL-C), and TC/HDL-C were assessed. Lipids and apoproteins were measured by standard laboratory procedures; FER(HDL) was determined by a radioassay.

RESULTS

Members of the aCAD(+) group were older and had a higher incidence of smoking and diabetes than those in the aCAD(-) group. The aCAD(+) group also had higher TG, apoB, FER(HDL), and log(TG/HDL-C) and lower HDL-C values. aCAD(+) women had greater waist circumference and higher plasma TC and TC/HDL-C. aCAD(+) men, but not women, had higher plasma LDL-C. In the multivariate logistic model, the significant predictors of the presence of aCAD(+) were FER(HDL), age, smoking, and diabetes. If only laboratory tests were included in the multivariate logistic model, FER(HDL) appeared as the sole predictor of aCAD(+). Log(TG/HDL-C) was an independent predictor when FER(HDL) was omitted from multivariate analysis.

CONCLUSIONS

FER(HDL) was the best laboratory predictor of the presence of coronary atherosclerotic lesions.

Markers of hypercoagulation and von Willebrand factor in postmenopausal women with unstable coronary artery disease. Discriminatory ability regarding unstable coronary artery disease and coronary atherosclerosis using receiver operating characteristics

OBJECTIVES

Many women with typical anginal chest pain have normal coronary angiograms. The pathogenetic mechanisms behind the chest pain in these patients are unknown but may be due to increased thrombogenicity. We evaluated markers of hypercoagulation and thrombosis in women with clinical signs of unstable coronary artery disease (CAD).

METHODS AND RESULTS

A total of 158 patients with unstable CAD and 101 controls were examined: 16% of the patients had normal vessels and 84% had coronary atherosclerosis at coronary angiography. Mean plasma concentrations of von Willebrand factor antigen, soluble fibrin (SF), thrombin-antithrombin complex and D-dimer were significantly higher, whereas there was no difference regarding prothrombin fragment 1+2 between patients and controls. Patients with coronary atherosclerosis had higher mean plasma levels for most variables compared with those with normal coronary vessels, although only significantly higher for SF. D-Dimer was significantly higher in patients with normal coronary vessels compared with the control group. Although multivariate analyses showed strong significant correlations of the haemostatic variables to the diagnosis of unstable CAD, receiver operating characteristics (ROC) revealed that none of the variables represented high diagnostic accuracy in separating patients with unstable CAD. Likewise, none of the variables was particularly good at identifying coronary atherosclerosis.

CONCLUSION

Our results are in favour of a hypercoagulable state in postmenopausal women with unstable CAD and coronary atherosclerosis, whereas this does not seem to be the case in patients with normal vessels. ROC revealed no variable to be particularly clinically useful in separating patients from controls or patients from those without coronary atherosclerosis.

Plasma total homocysteine levels in postmenopausal women with unstable coronary artery disease

An elevated plasma total homocysteine (tHcy) level is considered a risk factor for coronary artery disease (CAD), but the relationship between plasma tHcy and well-defined CAD in women is still unclear. Plasma tHcy concentrations and the covariates serum folate, vitamin B12, and creatinine were analysed in 157 angiographically examined postmenopausal women with unstable CAD and in 101 healthy controls. At coronary angiography, 16% had normal vessels and 84% had coronary atherosclerosis. Mean plasma tHcy concentration (micromol/l, 95% confidence interval) did not differ in patients compared to controls (13.1 (12.3-13.8) vs. 12.5 (11.6-13.5)) or in patients with or without coronary atherosclerosis (13.3 (12.4-14.1) vs. 12.0 (10.8-13.2)). A trend to an increasing plasma tHcy with increasing degree of coronary atherosclerosis was attenuated after adjustment for age and the previous mentioned covariates. Odds ratio for the risk of coronary artery disease and coronary atherosclerosis in hyperhomocysteinemic patients (> or =90th percentile in controls) was approximately 3. However, the confidence interval included unity in half of the groups and the significance was therefore difficult to judge. Receiver operating characteristics showed age to be the only variable with a significant discriminatory ability regarding the presence of coronary atherosclerosis (area 0.77). Mild hyperhomocysteinemia seems not to be related to the risk of unstable CAD in postmenopausal women. The trend towards higher plasma tHcy with increasing degree of coronary atherosclerosis may be a marker of the disease. In future studies adjustment for age and the other three covariates should be considered.