Non-high-density lipoprotein cholesterol and coronary artery calcium progression in a multiethnic US population

Dyslipidemia and coronary artery calcium: From association to development of a risk-prediction nomogram

BACKGROUND AND AIMS

The associations between dyslipidemia and coronary artery calcium (CAC) are controversial. We investigated their cross-sectional relationships and developed a predictive scoring system for prognostically significant coronary calcification (PSCC).

METHODS AND RESULTS

This study evaluated the lipid profiles and the CAC score (CACS) measured through multidetector computed tomography (MDCT) among Taiwanese adult patients in a tertiary hospital between 2011 and 2016. Patients with CACS higher than 100 were classified as having PSCC. Dyslipidemia for each lipid component was defined based on the clinical cutoffs or the use of the lipid-lowering agents. Multivariable logistic regression was used to assess the association between dyslipidemia and PSCC and the model performance was assessed using calibration plot, discrimination, and a decision curve analysis. Of the 3586 eligible patients, 364 (10.2%) had PSCC. Increased age, male sex, higher body mass index (BMI), and higher level of triglyceride (TG) were associated with PSCC. The adjusted odds ratios (95% confidence intervals) of PSCC was 1.15 (0.90-1.47) for dyslipidemia defined by total cholesterol (TC) ≥200 mg/dL, 1.06 (0.83-1.35) for low-density-lipoprotein-cholesterol (LDL-C) ≥130 mg/dL, and 1.36 (1.06-1.75) for TG ≥ 200 mg/dL. The positive association between TG ≥ 200 mg/dL and PSCC was not modified by sex. Incorporating hypertriglyceridemia did not significantly improve the predictive performance of the base model comprising of age, sex, BMI, smoking, hypertension, diabetes, estimated glomerular filtration rate, and fasting glucose.

CONCLUSIONS

Hypertriglyceridemia was significantly associated with the prevalent odds of PSCC. Our proposed predictive model may be a useful screening tool for PSCC.

U-Shaped Relationship of Non-HDL Cholesterol With All-Cause and Cardiovascular Mortality in Men Without Statin Therapy

Background

Non-HDL-C is well established causal risk factor for the progression of atherosclerotic cardiovascular disease. However, there remains a controversial pattern of how non-HDL-C relates to all-cause and cardiovascular mortality, and the concentration of non-HDL-C where the risk of mortality is lowest is not defined.

Methods

A population-based cohort study using data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2014. Male participants without statin therapy were divided into the six groups according to non-HDL-C levels (<100, 100–129, 130–159, 160–189, 190–219, ≥220 mg/dl). Multivariable Cox proportional hazards models were conducted with a hazard ratio (HR) and corresponding 95% confidence interval (CI). To further explore the relationship between non-HDL-C and mortality, Kaplan–Meier survival curves, restricted cubic spline curves, and subgroup analysis were performed.

Results

Among 12,574 individuals (average age 44.29 ± 16.37 years), 1,174(9.34%) deaths during a median follow-up 98.38 months. Both low and high non-HDL-C levels were significantly associated with increased risk of all-cause and cardiovascular mortality, indicating a U-shaped association. Threshold values were detected at 144 mg/dl for all-cause mortality and 142 mg/dl for cardiovascular mortality. Below the threshold, per 30 mg/dl increase in non-HDL-C reduced a 28 and 40% increased risk of all-cause (p < 0.0001) and cardiovascular mortality (p = 0.0037), respectively. Inversely, above the threshold, per 30 mg/dl increase in non-HDL-C accelerated risk of both all-cause mortality (HR 1.11, 95% CI 1.03–1.20, p = 0.0057) and cardiovascular mortality (HR 1.30, 95% CI 1.09–1.54, p = 0.0028).

Conclusions

Non-HDL-C was U-shaped related to all-cause and cardiovascular mortality among men without statin therapy.

Causal effects of dietary calcium, zinc and iron intakes on coronary artery disease in men: G-estimation and inverse probability of treatment weighting (IPTW) analyses

BACKGROUND & AIMS

Dietary minerals have significant effects on the risk of cardiovascular disease. However, the results of previous studies were not uniform across different countries. The current study aims to determine the causal effects of dietary calcium, zinc, and iron intakes on coronary artery disease (CAD) among Nepalese men.

METHODS

A matched case-control study was carried out at Shahid Gangalal National Heart Center. Dietary intakes of 466 male participants over the past 12 months were evaluated using a semi-quantitative customized food frequency questionnaire. G-estimation and inverse probability treatment weighting (IPTW) analyses were performed to determine the causal odds of CAD due to dietary calcium, zinc, and iron intakes.

RESULTS

Daily dietary calcium, zinc, and iron intakes were categorized into two groups: less than versus more than the median value and less than versus equal or more than recommended daily allowance (RDA). In G-estimation, dietary calcium intake was inversely associated with CAD in both medians (OR: 91; 91%CI: 0.86, 95) and RDA categories (OR: 0.88: 95%CI: 0.84, 0.97). However, in IPTW analysis, only median calcium intake was significantly associated with CAD (OR: 7; 91%CI: 0.5, 98). We observed a significant inverse association of equal or more than RDA of dietary zinc intake with CAD (OR: 0.91: 95%CI: 0.87, 0.96 in G-estimation, OR: 0.73: 95%CI: 0.66, 0.82 in IPTW); however, more than median dietary zinc intake showed inverse but not significant association with CAD in both analyses. Dietary iron intake was inversely but not significantly associated with CAD in G-estimation in both groups. Nevertheless, in IPTW analysis, equal or more than RDA iron intake was significantly positively (OR: 1.4; 95%CI: 1.14, 1.73) related to CAD.

CONCLUSIONS

A significant inverse association of dietary zinc intake above RDA indicates the potential protective effect of higher dietary zinc against CAD. However, causal odds of CAD are inconsistent across the median or RDA of calcium and iron intakes. Therefore, cohort and randomized clinical trial studies with a large sample size are recommended to substantiate these nutrients' causal link with CAD development in the Nepalese population.

The Correlation of Dyslipidemia with the Extent of Coronary Artery Disease in the Multiethnic Study of Atherosclerosis

Background

The extent of coronary artery calcium (CAC) improves cardiovascular disease (CVD) risk prediction. The association between common dyslipidemias (combined hyperlipidemia, simple hypercholesterolemia, metabolic Syndrome (MetS), isolated low high-density lipoprotein cholesterol, and isolated hypertriglyceridemia) compared with normolipidemia and the risk of multivessel CAC is underinvestigated.

Objectives

To determine whether there is an association between common dyslipidemias compared with normolipidemia, and the extent of coronary artery involvement among MESA participants who were free of clinical cardiovascular disease at baseline.

Methods

In a cross-sectional analysis, 4,917 MESA participants were classified into six groups defined by specific LDL-c, HDL-c, or triglyceride cutoff points. Multivessel CAC was defined as involvement of at least 2 coronary arteries. Multivariate Poisson regression analysis evaluated the association of each group with multivessel CAC after adjusting for CVD risk factors.

Results

Unadjusted analysis showed that all groups except hypertriglyceridemia had statistically significant prevalence ratios of having multivessel CAC as compared to the normolipidemia group. The same groups maintained statistical significance prevalence ratios with multivariate analysis adjusting for other risk factors including Agatston CAC score [combined hyperlipidemia 1.41 (1.06-1.87), hypercholesterolemia 1.55 (1.26-1.92), MetS 1.28 (1.09-1.51), and low HDL-c 1.20 (1.02-1.40)].

Conclusion

Combined hyperlipidemia, simple hypercholesterolemia, MetS, and low HDL-c were associated with multivessel coronary artery disease independent of CVD risk factors and CAC score. These findings may lay the groundwork for further analysis of the underlying mechanisms in the observed relationship, as well as for the development of clinical strategies for primary prevention.

Concerns About the Use of Non-High-Density Lipoprotein Cholesterol as a Lipid Predictor

Introduction: Non-high-density lipoprotein (non-HDL) cholesterol is the sum of low-density lipoprotein (LDL) cholesterol and very-low-density lipoprotein (VLDL) cholesterol, and is usually approximated by the total cholesterol minus HDL-cholesterol. The National Lipid Association (NLA) has advocated the use of non-HDL cholesterol as its favoured lipid predictor. Cut-off points are based on LDL cholesterol values, with a lower end at 100 mg/dL (2.50 mmol/L) and a higher end at 190 mg/dL (4.75 mmol/L), adding 30 mg/dL (0.75 mmol/L) to keep triglyceride (TG) levels <150 mg/dL (1.70 mmol/L). Objectives: The author will demonstrate that the use of non-HDL cholesterol has not been fully considered. Methods: The author will examine a general population lipid database to demonstrate the frequency of distribution of non-HDL cholesterol in the part of the population that was known to have developed a form of atherothrombotic disease (ATD) and in the part that was not known to have done so. The effect of stratifying each non-HDL cholesterol quintile in terms of another lipid predictor that does not involve VLDL-cholesterol or TG will be demonstrated. The other risk predictor is the cholesterol retention fraction (CRF) defined as (LDL-HDL)/LDL. Findings: All non-HDL cholesterol quintiles above the lowest quintile had higher frequencies in the ATD population than in the non-ATD population. The highest two quintiles had frequencies in the ATD population that are 2.5-times as high as those in the non-ATD population, whereas in the middle two quintiles, the frequency in the ATD population was minimally higher than in the non-ATD population. In the lowest quintile, the frequency is much higher in the non-ATD population than in the ATD population. At any non-HDL cholesterol quintile, the average age of ATD onset depends on cigarette smoking (not discussed here) and the CRF. Higher CRF levels equate to an earlier average age of ATD onset and lower levels of CRF equate to a later onset. A 75-year-old male who was a hypertensive diabetic and a former smoker was not on statins because of low lipid levels, had clean arteries on angiography, whereas a 45-year-old normotensive, non-smoking patient with severe dyslipidaemia (obtained at first encounter) had a massive stroke due to carotid stenosis. Both had non-HDL cholesterol levels in the intermediate ATD risk quintiles. Conclusions: Non-HDL cholesterol is not the optimal predictor of the population at risk of atherothrombotic disease and its use should be reconsidered.

Distribution of ABO Blood Groups and Coronary Artery Calcium

BACKGROUND

ABO blood groups have been confirmed to be associated with cardiovascular diseases such as coronary artery disease. However, whether ABO blood group is correlated with coronary artery calcium (CAC) is still unknown.

METHOD

301 patients with coronary artery calcium score (CACS) assessed by computed tomography were consecutively enrolled and divided into two groups: with calcium group (CACS>0, n=104) and without calcium group (CACS=0, n=197). Distribution of ABO blood groups was evaluated between the two groups.

RESULTS

The percentage of A blood type was significantly higher (p=0.008) and O blood type was significantly lower (p=0.037) in the calcium group. Univariate regression analysis showed that age, total cholesterol, low density lipoprotein cholesterol, high-sensitivity C-reactive protein, A blood type were positively correlated with CAC, and O blood type was inversely associated with CAC. Multivariate regression analysis showed that A blood type was independently associated with CAC (odds ratio: 2.217, 95% confidence interval: 1.260-3.900, p=0.006) even after further adjustment for variables that were clearly different between the two groups.

CONCLUSIONS

Our data has suggested for the first time that A blood type was an independent risk marker for CAC.

Non-high-density lipoprotein cholesterol: current status as cardiovascular marker

PURPOSE OF REVIEW

In this review, we summarize the evidence with regard to the rationale of using nonhigh density lipoprotein cholesterol (non-HDL-C) as a cardiovascular disease (CVD) risk factor, in relation to low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (apoB).

RECENT FINDINGS

In the 2015 National Lipid Association Annual Summary non-HDL-C is considered a coprimary target, apart from LDL-C. The other data published in the last 18 months about non-HDL-C support all the previous published data. There are no recent findings, which we deem to cause a change of the current opinion about non-HDL-C as a predictor for CVD.

SUMMARY

The existing evidence supports the claim that non-HDL-C is superior to LDL-C in CVD risk estimation.