Is the superiority of apoB over non-HDL-C as a marker of cardiovascular risk in the INTERHEART study due to confounding by related variables?

Discordantly high Apo B with LDL-C or non-HDL-C in relation to presence and burden of cerebral atherosclerotic plaques

BACKGROUND

Data are limited on associations between apolipoprotein B (Apo B) and cerebral atherosclerosis.

OBJECTIVE

Our study aimed to estimate associations between discordant Apo B with low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (Non-HDL-C) and the odds of the presence and burden of intra-/extra-cranial atherosclerotic plaques.

METHODS

This cross-sectional study was based on the baseline survey from the PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events (PRECISE) study, a population-based prospective cohort study. Participants with complete baseline data but without taking lipid-lowering medication were included in this analysis. Discordant Apo B with LDL-C or Non-HDL-C were defined by residuals and cut-off values (LDL-C: 3.4 mmol/L, Non-HDL-C: 4.1 mmol/L). We used binary and ordinal logistic regression models to explore associations between discordant Apo B with LDL-C or Non-HDL-C and the presence and burden of intra-/extra-cranial atherosclerotic plaques.

RESULTS

A total of 2,943 participants were enrolled in this study. Discordantly high Apo B with LDL-C was associated with an increased odds of the presence of intracranial atherosclerotic plaque [odds ratio (OR),1.28; 95%CI,1.01-1.61], intracranial atherosclerotic burden [common odds ratio (cOR), 1.31; 95%CI,1.04-1.64], the presence of extracranial atherosclerotic plaque (OR, 1.37; 95%CI,1.14-1.66), and extracranial atherosclerotic burden (cOR, 1.32; 95%CI,1.10-1.58) compared with the concordant group. Discordantly low Apo B with Non-HDL-C was associated with decreased odds of the presence and burden of intra-/extra-cranial atherosclerotic plaques.

CONCLUSION

Discordantly high Apo B with LDL-C or Non-HDL-C were associated with an increased odds of the presence and burden of intra-/extra-cranial atherosclerotic plaques. This demonstrated that discordantly high Apo B might be important for early assessment of risk of cerebral atherosclerotic plaques in addition to LDL-C and Non-HDL-C.

Discordance of Low-Density Lipoprotein Cholestrol and Non-High-Density Lipoprotein Cholestrol and Coronary Artery Disease Severity

BACKGROUND

A sizeable proportion of patients have discordant low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C).

OBJECTIVES

We assessed the relationship between discordance of LDL-C and non-HDL-C and coronary artery disease (CAD) severity.

METHODS

We retrospectively evaluated the data of 574 consecutive patients who underwent coronary angiography. Fasting serum lipid profiles were recorded, SYNTAX and Gensini scores were calculated to establish CAD complexity and severity. We determined the medians for LDL-C and non-HDL-C to examine the discordance between LDL-C and non-HDL-C. Discordance was defined as LDL-C greater than or equal to the median and non-HDL-C less than median; or LDL-C less than median and non-HDL-C greater than or equal to median. A p value < 0.05 was accepted as statistically significant.

RESULTS

LDL-C levels were strongly and positively correlated with non-HDL-C levels (r = 0.865, p < 0.001) but 15% of patients had discordance between LDL-C and non-HDL-C. The percentage of patients with a Gensini score of zero or SYNTAX score of zero did not differ between discordant or concordant groups (p = 0.837, p = 0.821, respectively). Mean Gensini and SYNTAX scores, percentage of patients with Gensini score ≥20 and SYNTAX score >22 were not different from group to group (p = 0.635, p = 0.733, p = 0.799, p = 0.891, respectively). Also, there was no statistically significant correlation between LDL-C and Gensini or SYNTAX scores in any of the discordant or concordant groups. Additionally, no correlation was found between non-HDL-C and Gensini or SYNTAX score.

CONCLUSIONS

While there was discordance between LDL-C and non-HDL-C (15% of patients), there is no difference regarding CAD severity and complexity between discordant and concordant groups.

Serum apolipoprotein B is associated with increased risk of metabolic syndrome among middle-aged and elderly Chinese: A cross-sectional and prospective cohort study

BACKGROUND

Serum apolipoprotein (apo) B has been associated with an increased risk of atherosclerotic cardiovascular diseases. However, findings on the association between apoB and the risk of metabolic syndrome (MetS) are inconsistent. The purpose of this study was to investigate the association between serum apoB and MetS risk in Chinese population.

METHODS

A baseline survey was conducted in a population-based cohort of 10 340 adults aged ≥40 years in Shanghai, China, in 2010. A follow-up visit was conducted to assess incident diabetes in 2015.

RESULTS

At baseline, 2794 of 10 340 participants (27.02%) had MetS. Serum apoB was significantly associated with an increased risk of prevalent MetS. Multivariable-adjusted odds ratios and 95% confidence intervals (CIs) for quintiles 2-5 compared with quintile 1 (reference) were 1.29 (1.02-1.63), 1.47 (1.18-1.84), 1.32 (1.06-1.65), and 2.02 (1.61-2.51), respectively (P_trend  < 0.05). During an average of 5.1 years follow-up, 4627 individuals without MetS at baseline showed a significant association between apoB and the risk of incident MetS. Multivariable-adjusted risk ratios (95% CIs) for subjects in apoB quintiles 2-5 compared with the reference were 1.43 (1.13-1.82), 1.57 (1.25-1.98), 1.74 (1.38-2.18), and 2.07 (1.66-2.58), respectively (P_trend  < 0.05). Stratified analysis suggested that the above association was much stronger among normal weight individuals than in those who were overweight or obese.

CONCLUSION

These cross-sectional and prospective studies provide evidence that serum apoB is associated with existing MetS and is a possible predictor of the risk of MetS, especially among normal weight individuals.

Association between discordance of LDL-C and non-HDL-C and clinical outcomes in patients with stent implantation: from the FU-Registry

It is not yet clear whether the discordance of low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) predicts the follow-up clinical outcome (major adverse cardiovascular events: MACEs) in patients with coronary stent implantation. Among 2015 patients with coronary stent implantation (Fukuoka University [FU]-Registry), excluding those with acute coronary syndrome or hemodialysis, we selected 801 patients who had undergone successful stent implantation with a follow-up until 18 months, and classified them into 3 groups according to baseline LDL-C and non-HDL-C levels [percentile(P)non-HDL-C more than (P)LDL-C, (P)non-HDL-C equal to (P)LDL-C, and (P)non-HDL-C less than (P) LDL-C]. We found that the discordance of (P)LDL-C and (P)non-HDL-C was not a significant predictor of MACEs. Higher LDL-C level was consistently and independently associated with higher incidences of MACEs after controlling for conventional risk factors and the type of stent used by multivariate Cox regression analyses. In conclusion, LDL-C levels are more important than non-HDL-C levels and the discordance of LDL-C and non-HDL-C levels as predictors of MACEs in patients with stable angina after stent implantation.

Association of Apolipoproteins B and A-1 With Markers of Vascular Health or Cardiovascular Events

BACKGROUND

Apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-1) are markers of lipoprotein metabolism. Although their relationship to cardiovascular disease has been well documented, little is known regarding their correlation to measures of vascular structure and function. This study was conducted to investigate the relationship between apoA-1, apoB, and measures of vascular function, as well their relationship to adverse cardiovascular events. Moreover, we evaluated whether apoB or the apoB/apoA-1 ratio was more closely related to vascular markers than was low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C).

METHODS

One thousand five hundred twenty-two healthy middle-aged men of the Firefighters and Their Endothelium (FATE) cohort were assessed for risk factors and flow-mediated dilatation (FMD), hyperemic velocity (VTI), and carotid intima-media thickness (CIMT). Participants were then followed for 7.2 ± 1.7 years. ApoA-1 and apoB levels were measured at baseline.

RESULTS

ApoA-1 was not correlated with VTI, FMD, or CIMT, whereas apoB was significantly related to VTI and CIMT. Multiple regression analyses confirmed apoB as being related to both VTI (β = -0.083; P = 0.001) and CIMT (β = 0.055; P = 0.022) in models adjusted for age; blood pressure; high-density lipoprotein C (HDL-C), triglyceride and insulin levels; waist circumference; and C-reactive protein levels. In substituted models, LDL-C (β = -0.092; P < 0.001) and non-HDL-C (β = -0.089; P = 0.001) levels appeared to have the same degree of association as apoB for VTI but were not associated with CIMT. ApoB was found to be associated with cardiovascular events (hazard ratio, 1.349; 95% confidence interval, 1.073-1.695; P = 0.010).

CONCLUSIONS

ApoB had an independent but weak relationship with indices of microvascular health. Nevertheless, it was associated with occurrence rates of adverse cardiovascular events.

Non-HDL-C is a Better Predictor for the Severity of Coronary Atherosclerosis Compared with LDL-C

BACKGROUND

Recent guidelines recommended both low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) are the primary target of lipid modulating therapy. However, which lipid measure is most closely related to the severity of coronary atherosclerosis has not yet been assessed.

METHODS

We studied 1757 consecutive subjects undergoing coronary angiography who were not receiving any lipid-lowering therapy. Low-density lipoprotein cholesterol was measured directly, and non-HDL-C was calculated. The severity of coronary stenosis was determined using the Gensini Score (GS) system.

RESULTS

In the overall population, LDL-C and non-HDL-C were all dramatically increased according to the quartiles of GS (p<0.001, both). In patients with coronary atherosclerosis (n=1097), non-HDL-C (r=0.138, p<0.001) was more closely related to GS than LDL-C (r=0.113, p<0.001) tested by Spearman correlation analysis. Multivariate logistic regression analysis suggested that non-HDL-C (OR=1.326, 95% CI 1.165-1.508, p<0.001) was slightly superior to LDL-C (OR=1.286, 95% CI 1.130-1.463, p<0.001) in predicting high GS after adjusting for potential confounders. Among patients with LDL-C less than the median, discordant non-HDL-C could not provide extra value in predicting high GS (OR=0.759, 95% CI 0.480-1.201). However, among patients with LDL-C greater than or equal to the median, the cardiovascular risk was overestimated for patients with discordant non-HDL-C (OR=0.458, 95% CI 0.285-0.736).

CONCLUSIONS

Our data support the use of non-HDL-C ahead of LDL-C in predicting the severity of coronary atherosclerosis, especially among patients with LDL-C greater than or equal to the median.

Discordance Between Apolipoprotein B and LDL-Cholesterol in Young Adults Predicts Coronary Artery Calcification: The CARDIA Study

BACKGROUND

High levels of apolipoprotein B (apoB) have been shown to predict atherosclerotic cardiovascular disease (CVD) in adults even in the context of low levels of low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C).

OBJECTIVES

This study aimed to quantify the associations between apoB and the discordance between apoB and LDL-C or non-HDL-C in young adults and measured coronary artery calcium (CAC) in midlife.

METHODS

Data were derived from a multicenter cohort study of young adults recruited at ages 18 to 30 years. All participants with complete baseline CVD risk factor data, including apoB and year 25 (Y25) CAC score, were entered into this study. Presence of CAC was defined as having a positive, nonzero Agatston score as determined by computed tomography. Baseline apoB values were divided into tertiles of 4 mutually exclusive concordant/discordant groups, based on median apoB and LDL-C or non-HDL-C.

RESULTS

Analysis included 2,794 participants (mean age: 25 ± 3.6 years; body mass index: 24.5 ± 5 kg/m(2); and 44.4% male). Mean lipid values were as follows: total cholesterol: 177.3 ± 33.1 mg/dl; LDL-C: 109.9 ± 31.1 mg/dl; non-HDL-C: 124.0 ± 33.5 mg/dl; HDL-C: 53 ± 12.8 mg/dl; and apoB: 90.7 ± 24 mg/dl; median triglycerides were 61 mg/dl. Compared with the lowest apoB tertile, higher odds of developing Y25 CAC were seen in the middle (odds ratio [OR]: 1.53) and high (OR: 2.28) tertiles based on traditional risk factor-adjusted models. High apoB and low LDL-C or non-HDL-C discordance was also associated with Y25 CAC in adjusted models (OR: 1.55 and OR: 1.45, respectively).

CONCLUSIONS

These data suggest a dose-response association between apoB in young adults and the presence of midlife CAC independent of baseline traditional CVD risk factors.