Non-HDL Cholesterol as a Predictor of Carotid Atherosclerosis in the Elderly

Association between non-high-density lipoprotein cholesterol levels and asymptomatic vulnerable carotid atherosclerotic plaques

BACKGROUND AND PURPOSE

Carotid atherosclerosis, especially rupture of plaques, is related to cerebrovascular diseases. Non-high-density lipoprotein cholesterol (non-HDL-C) is relevant to cerebrovascular diseases and may be a potential risk factor. We designed this study to investigate the association between non-HDL-C and the prevalence of asymptomatic vulnerable carotid atherosclerotic plaques.

METHODS

We enrolled 2888 participants who underwent carotid atherosclerotic plaque detection and non-HDL-C measurement, with no history of taking lipid-lowering agents, from the Asymptomatic Polyvascular Abnormalities in Community study. We used multivariable logistic regression to estimate the association between non-HDL-C levels and the presence of asymptomatic vulnerable carotid atherosclerotic plaques.

RESULTS

In our study, 1505 subjects had asymptomatic vulnerable carotid atherosclerotic plaques and 1383 subjects had stable plaques. After adjustment for confounding factors, the odds ratios for vulnerable plaques of non-HDL-C levels in the middle and highest tertile groups were 1.02 (95% confidence interval, 0.84-1.23) and 1.50 (95% confidence interval, 1.23-1.82), respectively (P trend < 0.01).

CONCLUSION

In our community-based observational and cross-sectional study, non-HDL-C level was a significant risk factor for the occurrence of asymptomatic vulnerable carotid plaques.

Apolipoprotein B vs non-high-density lipoprotein cholesterol: Association with endothelial hemostatic markers and carotid intima-media thickness

BACKGROUND

Both apolipoprotein B (apoB) and non-high-density lipoprotein cholesterol (non-HDL-C) are accepted as alternative risk factors or targets for lipid-lowering therapy, which correlate more strongly with cardiovascular events than low-density lipoprotein cholesterol.

OBJECTIVE

The aim of this cross-sectional study was to evaluate the differences in plasma levels of plasminogen activator inhibitor-1 (PAI-1) and of von Willebrand factor (vWF) as endothelial hemostatic markers and carotid intima-media thickness (C-IMT) as a morphologic marker for atherosclerotic vascular disease among dyslipidemic individuals with apoB levels higher, estimated or lower based on regression equation of apoB vs non-HDL-C.

METHODS

A total of 594 dyslipidemic subjects without atherosclerotic manifestation were divided into 3 groups (according to tertiles of apoB levels above, within, and below the line of identity): H-apoB (n = 200), E-apoB (n = 194), and L-apoB (n = 200). PAI-1, vWF, C-IMT and lipids, anthropometric parameters, markers of insulin resistance, and inflammation were measured. Differences in variables between groups were analyzed using analysis of variance.

RESULTS

There was a strong association between apoB and non-HDL-C. The correlations of apoB and of non-HDL-C with markers of endothelial damage and C-IMT were very similar. Despite these facts, individuals with higher apoB levels had significantly higher levels of PAI-1 compared with individuals with estimated (P < .05) or lower apoB (P < .001). There were no significant differences in vWF, C-IMT, markers of insulin resistance, obesity, and inflammation.

CONCLUSION

Individuals with apoB higher than predicted by non-HDL-C had significantly higher levels of PAI-1, which may contribute to the increased risk of future atherothrombotic events.

Mildly elevated serum total bilirubin levels are negatively associated with carotid atherosclerosis among elderly persons with type 2 diabetes

Diabetes is strongly associated with several mechanisms of tissue damage such as oxidative stress. Serum bilirubin may have a beneficial role in preventing oxidative changes in cardiovascular disease (CVD). Limited information is available on whether serum bilirubin is an independent confounding factor for carotid atherosclerosis among elderly persons with type 2 diabetes. The study subjects were 169 men aged 79 ± 8 (mean ± SD) years and 205 women aged 81 ± 8 years that were enrolled consecutively from patients in the medical department. Carotid intima-media thickness (IMT) and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that serum total bilirubin (β = -0.160) was significantly associated with carotid IMT. Compared to subjects with a serum total bilirubin of tertile-1 (0.13-0.58 mg/dL), the multivariate-adjusted odds ratio (95% confidence interval) of carotid IMT ≥1.0 mm including plaque and carotid plaque was 0.46 (0.23-0.93) and 0.32 (0.17-0.60) in the Tertile-3 group (0.87-1.93 mg/dL), respectively. Next, data were further stratified by gender, age, smoking status, medication and prevalence of CVD. There were no significant differences in serum total bilirubin levels between selected subgroups. Our data demonstrated a negative association between serum total bilirubin and carotid atherosclerosis among elderly persons with type 2 diabetes.

The correlation between serum lipid profile with carotid intima-media thickness and plaque

Background

It is indicated that non-HDL cholesterol and lipid ratios, including total/HDL cholesterol and LDL/HDL cholesterol ratios, are risk indicators with greater predictive value for coronary atherosclerotic progression or regression compared with conventional lipid profile. However, there have been few reports about the correlation between serum lipid profile with carotid intima-media thickness (IMT) and plaque in Chinese general people.

Methods

We examined 402 subjects without apparent diseases in a cross-sectional study (mean age 50.16 years; 36.07% female). Demographics, anthropometrics, and laboratory data were collected. The presence of carotid plaque and intima-media thickness were evaluated by ultrasonography.

Results

Univariate correlations showed carotid IMT was correlated with LDL-C (r = 0.137, p = 0.009), non-LDL-C levels (r = 0.140, p = 0.008) and LDL-C/HDL-C ratio (r = 0.169, p = 0.001). After adjustment for potential covariates, LDL-C/HDL-C ratio (β = 0.132, p < 0.001) were independent variables that interacted on carotid IMT. Other risk factors including age and systolic blood pressure were independently associated with carotid IMT. LDL-C levels, non-HDL-C levels, TC/HDL-C and LDL-C/HDL-C ratios were significantly higher, but HDL-C levels were significantly lower in subjects with carotid plaque than those without it. The subsequent multiple logistic regression analysis showed that LDL-C (OR; 1.325, 95% CI; 1.046-1.821, p = 0.033) and HDL-C levels (OR; 0.093, 95% CI; 0.038-0.227, p < 0.001) were significantly associated with the presence of carotid plaque after adjustment of age. Furthermore, LDL-C combined with HDL-C levels showed the highest area under the curve (0.788, 95% CI; 0.740–0.837, p < 0.001).

Conclusions

Serum LDL-C/HDL-C ratio represents as an independent index associated with increased carotid IMT and LDL-C combined with HDL-C levels may be useful markers for predicting the presence of carotid plaque in the Chinese general population.

Mildly elevated serum bilirubin levels are negatively associated with carotid atherosclerosis among elderly persons

Serum bilirubin may have a beneficial role in preventing oxidative changes in atherosclerosis. Limited information is available on whether serum total bilirubin is an independent confounding factor for carotid atherosclerosis {for example, intima-media thickness (IMT), plaque} measured noninvasively by B-mode ultrasonography only among elderly persons. The study subjects were 325 men aged 79±8 (mean ± standard deviation) years and 509 women aged 81±8 years that were enrolled consecutively from patients aged ≥60 years in the medical department. Carotid IMT and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that in men age (β = 0.199, p = 0.002), smoking status (β = 0.154, p = 0.006), GGT (β = -0.139, p = 0.039), and GGT (β = -0.133, p = 0.022) were significantly and independently associated with carotid IMT, and in women age (β = 0.186, p<0.001), systolic blood pressure (β = 0.104, p = 0.046), diastolic blood pressure (β = -0.148, p = 0.004), prevalence of antihypertensive medication (β = 0.126, p = 0.004), fasting plasma glucose (β = 0.135, p = 0.003), GGT (β = -0.104, p = 0.032), estimated glomerular filtration rate, serum bilirubin (β = -0.119, p = 0.006), and prevalence of cardiovascular disease (CVD) (β = 0.103, p = 0.017) were also independently associated with carotid IMT. The odds ratios (ORs) {95% confidence interval (CI)} of increasing serum bilirubin category were negatively associated with carotid IMT ≥1.0 mm and plaque in both genders. Compared to subjects with a serum bilirubin of Quartile-1, the multivariate-OR (95% CI) of carotid plaque was 0.25 (0.11–0.57) in the Quartile-4 male group, and 0.41 (0.21–0.78) in the Quartile-2 female group, 0.51 (0.26–0.98) in the Quartile-3 female group, and 0.46 (0.24–0.89) in the Quartile-4 female group. Our data demonstrated an independently negative association between serum bilirubin and carotid atherosclerosis in both genders.

Serum non-high-density lipoprotein cholesterol levels and the incidence of ischemic stroke in a Japanese population: the Jichi Medical School cohort study

The predictive value of serum non-high-density lipoprotein cholesterol (non-HDL-C) levels for the incidence of ischemic stroke and its subtypes has not yet been established. The present cohort study investigated their relationships in a Japanese population. The first incidence of ischemic stroke and its subtypes was documented as the primary outcome. A total of 249 ischemic stroke patients (men/women = 145/104) were identified during a follow-up period of 10.7 years among 10 760 community-dwelling subjects (men/women = 4212/6548). Cox proportional hazard model analyses revealed that when compared with the lowest tertile of non-HDL-C, multivariate-adjusted hazard ratios for the highest tertile were 0.55 (95% confidence interval = 0.32-0.95, P = .03) on ischemic stroke and 0.29 (95% confidence interval = 0.08-1.05, P = .06) on cardioembolic infarction in women. Men did not show such significant relationships. Low serum non-HDL-C levels may be a predictive marker associated with an increase in the incidence of ischemic stroke and possibly of cardioembolic infarction in Japanese women.

Usefulness of lipoprotein ratios in assessing carotid atherosclerosis in Japanese type 2 diabetic patients

OBJECTIVE

It is indicated that total/HDL cholesterol and LDL/HDL cholesterol ratios have more predictive power for cardiovascular disease compared to classic lipid parameters. However, there have been few reports about the usefulness of these indices for the assessment of early stage atherosclerosis in Japanese type 2 diabetic subjects.

METHODS

We examined the relation between various lipid parameters and carotid atherosclerosis in 934 type 2 diabetic subjects without apparent atherosclerotic diseases (males, 71.7%; age, 59.6 ± 10.5 years (mean ± SD)). Serum concentrations of total cholesterol (TC), HDL cholesterol (HDL-C), and triglyceride were measured. LDL cholesterol (LDL-C) level was calculated using the Friedewald formula. The presence of carotid plaque and intima-media thickness (IMT) were evaluated by ultrasonography.

RESULTS

A stepwise multivariate regression analysis demonstrated that HDL-C (β = -0.110, p<0.001), TC/HDL-C (β = 0.132, p < 0.001) and LDL-C/HDL-C ratios (β = 0.132, p < 0.001) were independent determinants of IMT even after adjustment of other conventional risk factors. However, there was no significant correlation between IMT and TC, triglyceride, LDL-C, and non-HDL-C levels. TC/HDL-C and LDL-C/HDL-C ratios and non-HDL-C levels were significantly higher, but HDL-C levels were significantly lower in patients with carotid plaque than those without it (p < 0.05). There was no significant difference between the groups regarding TC, LDL-C, and triglyceride levels. Furthermore, TC/HDL-C (OR; 1.34, p < 0.001) and LDL-C/HDL-C (OR; 1.54, p < 0.001) ratios showed a positive and linear relationship with the prevalence of carotid plaque, whether covariates were adjusted or not.

CONCLUSIONS

TC/HDL-C and LDL-C/HDL-C ratios are useful as a tool to assess the risk of early stage atherosclerosis in Japanese type 2 diabetic patients.

Age-dependent associations of smoking and drinking with non-high-density lipoprotein cholesterol

Serum high-density lipoprotein (HDL) cholesterol levels are influenced by habitual smoking and drinking. Non-HDL cholesterol is known to be a potent predictor of cardiovascular disease. However, it remains to be determined whether the associations of non-HDL cholesterol with smoking and drinking differ with age. The objectives of this study were to investigate relationships among smoking, drinking, and non-HDL cholesterol and to investigate interactions of age with smoking and drinking regarding serum non-HDL cholesterol levels. Subjects (54,020 Japanese men aged 20-69 years) were divided into drinkers and nondrinkers or into smokers and nonsmokers and were further divided into 5 age groups with 10-year intervals. Subjects in each age group were divided into 3 subgroups according to alcohol or cigarette consumption. The mean levels of serum non-HDL cholesterol calculated after adjustment for age and body mass index were compared among the groups. In nondrinkers, non-HDL cholesterol levels of subjects in their 40s or older were significantly higher in heavy smokers than in nonsmokers, whereas non-HDL cholesterol levels of subjects in their 20s and 30s were not significantly different among non-, light, and heavy smokers. In drinkers, non-HDL cholesterol levels of subjects in all age groups were not higher in light and heavy smokers than in nonsmokers. In nonsmokers, non-HDL cholesterol in subjects in their 30s or older was significantly lower in light and heavy drinkers than in nondrinkers, whereas this difference was not observed in subjects in their 20s. In smokers, non-HDL cholesterol levels of subjects in all age groups were significantly lower in light and heavy drinkers than in nondrinkers, and the differences in non-HDL cholesterol between drinkers and nondrinkers tended to increase with advance of age. The difference in non-HDL cholesterol between drinkers and nondrinkers tended to be greater in smokers than in nonsmokers. Thus, the associations of non-HDL cholesterol with smoking and drinking were modified by drinking and smoking, respectively. Smoking is associated with high non-HDL cholesterol in nondrinkers, and drinking is associated with low non-HDL cholesterol in nonsmokers; these associations are shown at middle and elderly ages but not at young ages.

Measurement of cholesterol concentrations of major serum lipoprotein classes in haemodialysis patients by anion-exchange chromatography

BACKGROUND

Increased triglyceride (TG)-rich lipoproteins and decreased HDL that are implicated in the progression of atherosclerotic vascular diseases, are present in serum samples of patients undergoing haemodialysis (HD) therapy. Therefore, it is important to measure serum TG-rich lipoprotein concentrations to prevent the diseases.

METHODS

The cholesterol concentrations of lipoprotein classes in serum samples from the HD patients (n = 18) and healthy subjects (n = 18) were analysed by our recently developed method of high-performance liquid chromatography (HPLC), in which the lipoprotein classes were separated using an anion-exchange column, and the cholesterol concentrations of each of those were measured enzymatically using a post-column reaction. The ability of fractionated lipoprotein cholesterol determination by this HPLC method is mostly equivalent to the determination ability of an ultracentrifugation (UC).

RESULTS

HDL, LDL, and TG-rich lipoproteins, i.e. IDL, VLDL and chylomicrons, were well separated in the chromatograms. HDL cholesterol concentrations in the HD patients were significantly lower than in the healthy subjects (P < 0.0001), and IDL cholesterol concentrations and VLDL cholesterol concentrations in the HD patients were significantly higher than in the healthy subjects (P < 0.05). Profiles of these measured lipoprotein values were consistent with the previously reported lipoprotein values, measured ultracentrifugally characteristic of HD patients.

CONCLUSION

These results suggest that the HPLC method may be sufficiently applied to the assessment of serum lipoprotein profile in HD patients in place of the other method including an UC.

The importance of non-HDL cholesterol reporting in lipid management

Plasma levels of lipids and lipoproteins are essential to the management of lipid disorders by generalists and by practitioners of the emerging specialty of clinical lipidology. The routine lipid panel consists of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides. Several additional lipid parameters are emerging as potentially valuable adjuncts to the standard panel, including measurements of apolipoproteins and LDL particle size and concentration, but most of these serve mainly as research tools at present. One major exception is non-HDL-C, which is readily available for routine clinical use. This review outlines some of the numerous research studies that clearly establish the clinical utility and even preeminence of non-HDL-C as a comprehensive measure of atherogenic lipoproteins. Non-HDL-C was highlighted as a key secondary goal of therapy several years ago in the National Cholesterol Education Program Adult Treatment Panel III national lipid treatment guidelines and recently was further emphasized as a major goal of therapy in the consensus guidelines for lipoprotein management in patients with cardiometabolic risk from the American Diabetes Association and the American College of Cardiology. Non-HDL-C is superior to LDL-C for the prediction of cardiovascular events and has many other compelling advantages over LDL-C and other traditional lipid parameters. Importantly, it can be calculated directly from values in routine lipid panels, at no added expense. It is our opinion that non-HDL-C should be reported on all routine lipid profiles and used regularly in the management of dyslipidemia for optimal prevention of atherosclerosis and cardiovascular disease.

Impact of C-reactive protein on the likelihood of carotid atherosclerosis in Japanese adults

OBJECTIVE

Several cohort studies have shown a link between serum C-reactive protein (CRP) and subsequent cardiovascular disease; however, the role of CRP as an independent risk factor remains controversial. We therefore investigated the association between CRP and sclerotic lesions of common carotid atherosclerosis.

PATIENTS AND METHODS

We evaluated sclerotic lesions of common carotid arterial intima-media thickness (IMT) by ultrasonography in 139 men aged 67 +/- 15 years and 201 women aged 75 +/- 10 years. To investigate the relation between CRP and various confounding factors, subjects were divided into four groups based on the quartile of CPR.

RESULTS

Carotid IMT values were significantly higher in groups with higher CRP (p = 0.022). To identify the possible CRP level and risk factor interactions for IMT, multiple regression analysis for IMT was performed based on risk factors in subjects with a specific CRP level. It was shown that age, smoking status, systolic blood pressure (SBP) and LDL cholesterol were significantly associated with IMT in subjects in the lower CRP groups (CRP-1 approximately CRP-3), and age, SBP and presence of diabetes mellitus in the highest CRP group (CRP-4). To further investigate whether the interaction between CRP and conventional risk factors could influence IMT, a general linear model demonstrated that interaction between CRP and the presence of diabetes mellitus (F = 4.754 p = 0.030) was significantly associated with IMT, in addition to sex, age, SBP, antihypertensive drug use, LDL cholesterol and HDL cholesterol.

CONCLUSIONS

This finding indicates that the association between CRP and IMT significantly differed between subjects with and without diabetes mellitus.

Lipoprotein (a) and risk of ischemic stroke in young adults

Lipoprotein (a) [Lp(a)] is a LDL-particle linked to apoprotein (a) [apo(a)]. High Lp(a) plasma level is a risk factor for coronary heart disease and, in older men, for ischemic stroke. The role of Lp(a) as a risk factor for ischemic stroke in young adults is uncertain.

METHODS

Lp(a) concentration was prospectively measured in 100 consecutive patients with acute ischemic stroke (58 men and 42 women) aged 18-55 years, and in 100 controls matched for age and gender.

RESULTS

The distribution of Lp(a) concentration was skewed toward the highest and median tertiles in male patients. In multivariate logistic regression analyses adjusting on classical risk factors for ischemic stroke and lipid variables, Lp(a) concentration in the highest and medium tertiles compared with the lowest tertile was significantly associated with ischemic stroke in men (OR 3.55, 95% CI 1.33-9.48, p = 0.012), but was not in women (OR 0.42, 95% CI 0.14-1.26, p = 0.12). Although large vessel atherosclerosis was more common in men than in women, there were no differences in Lp(a) concentration according to the cause of ischemic stroke.

CONCLUSION

Among subjects aged 18-55 years, a slightly elevated Lp(a) concentration was strongly and independently associated with ischemic stroke in men, but not in women. Further studies are required to elucidate the mechanisms underlying this gender-specific association.