Reprint of: Impact of Lipids on Cardiovascular Health: JACC Health Promotion Series

The associations between high-levels of urine benzophenone-type UV filters (BPs) and changes in serum lipid concentrations

Little is known about the potential health impacts of benzophenone-type UV filters (BPs) exposure among the general population. In our study conducted in Wuxi, China, we investigated the associations between the concentrations of eight BP-derivatives and five target lipid molecules. We collected basic information, serum, and urine samples from 120 residents aged 9 to 80 in Wuxi. We determined BPs in urine samples and lipid levels in serum samples. Generalized linear models were used to evaluate the differences in ln-transformed serum target lipids levels (μg/L) with different urine BPs quartiles compared to the lowest quartile. Benzophenone-4 (BP-4) had the highest detection rate (95.0%) and geometric mean concentration (1.96 μg/L) among all the BP-derivatives in our study population. The exposure levels of BPs were generally higher in females than in males. Participants in the 9-17 and 18-50 age groups exhibited greater levels of exposure to BPs than those in the 51-80 age group. We observed statistically significant changes in LysoPC (18:0), LysoPE (18:0), ΣLPL, and ΣTL concentrations between the highest and lowest quartiles of BP-4. Similar changes were found in LysoPE (18:0) concentration between the highest and lowest quartiles of ΣBP-3 and ΣBPs. High urine BP concentrations were associated with variations in our target serum lipids involved in neurological and metabolic disorders, and posed a potential health risk. Future studies are warranted to further validate and elucidate our findings.

Bempedoic Acid: Lipid Lowering for Cardiovascular Disease Prevention

The management of low-density lipoprotein cholesterol (LDL-C) levels is a central strategy for the prevention of atherosclerotic cardiovascular disease. Current United States (2018 American Heart Association/American College of Cardiology/Multisociety) and European (2019 European Society of Cardiology/European Atherosclerosis Society) guidelines endorse statin therapy as the first-line therapy for pharmacologic LDL-C lowering. However, in clinical practice up to 30% of patients report partial or complete intolerance to statin therapy. While the nocebo effect with statins is well described, perceived statin intolerance prevents many patients from achieving LDL-C thresholds associated with clinical benefit. Bempedoic acid is a novel, oral, non-statin lipid-l owering therapy that works by inhibiting adenosine triphosphate-citrate lyase, an enzymatic reaction upstream of 3-hydroxy-3-methylglutaryl coenzyme A reductase in the hepatic cholesterol synthesis pathway. Bempedoic acid confers reduction in LDL-C of ~18% on background statin therapy,~21% in patients with statin intolerance, and ~38% when given in fixed-dose combination with ezetimibe. The CLEAR Outcomes trial, which enrolled high-risk primary and secondary prevention patients with reported statin intolerance and LDL-C levels ≥100 mg/dL, showed that bempedoic acid compared with placebo reduced 4-component major adverse cardiovascular events (MACE) by 13% (hazard ratio 0.87, 95% confidence interval 0.79-0.96). Bempedoic acid also reduced 3-component MACE by 15%, myocardial infarction by 23% and coronary revascularization by 19%. The benefit was even greater in the primary prevention cohort (hazard ratio 0.70, 95% confidence interval 0.55-0.89) for 4-component MACE. Bempedoic acid was associated with increases in uric acid levels and cholelithiasis, but numerically fewer events of myalgia and new-onset diabetes. These findings confirm that bempedoic acid is an effective approach to reduce cardiovascular outcomes in high-risk patients with statin intolerance who require further reduction in LDL-C.

LDL-C target attainment in secondary prevention of ASCVD in the United States: barriers, consequences of nonachievement, and strategies to reach goals

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death in the United States. Elevated low-density lipoprotein cholesterol (LDL-C) is a major causal risk factor for ASCVD. Current evidence overwhelmingly demonstrates that lowering LDL-C reduces the risk of secondary cardiovascular events in patients with previous myocardial infarction or stroke. There is no lower limit for LDL-C: large, randomized studies and meta-analyses have found continuous benefit and no safety concerns in patients achieving LDL-C levels <25 mg/dL. As 'Time is plaque' in patients with ASCVD, early, sustained reductions in LDL-C are critical to slow or halt disease progression. However, despite use of lipid-lowering medications, <30% of patients with ASCVD achieve guideline-recommended reductions in LDL-C, resulting in a substantial societal burden of preventable cardiovascular events and early mortality. LDL-C goals are not met due to several factors: lipid-lowering therapy is not initiated and intensified as directed by clinical guidelines (clinical inertia); most patients do not adhere to prescribed medications; and high-risk patients are frequently denied access to add-on therapies by their insurance providers. Promoting patient and clinician education, multidisciplinary collaboration, and other interventions may help to overcome these barriers. Ultimately, achieving population-level guideline-recommended reductions in LDL-C will require a collaborative effort from patients, clinicians, relevant professional societies, drug manufacturers, and payers.

Hepatic miR-378 modulates serum cholesterol levels by regulating hepatic bile acid synthesis

Rationale: An improved understanding of thyroid hormone (TH) action on cholesterol metabolism will facilitate the identification of novel therapeutic targets for hypercholesterolemia. TH-regulated microRNAs (miRNAs) have been implicated in TH-controlled biological processes; however, whether and how TH-regulated miRNAs mediate the cholesterol-lowering effect of TH remains unclear. Our aim was to identify TH-regulated microRNAs that have cholesterol-lowering effects and explore the underlying mechanism.

Method: Microarray and RNA-seq were performed to identify TH-regulated microRNAs and the genes regulated by mmu-miR-378-3p (miR-378) in the liver of mice, respectively. Recombinant adenoviruses encoding miR-378, Mafg, and shRNA for Mafg, antagomiR-378, liver-specific miR-378 transgenic mice, and miR-378 knockout mice were employed to investigate the roles of hepatic miR-378 and MAFG in cholesterol and bile acid homeostasis. The levels of bile salt species were determined by using UFLC-Triple-time of flight/MS.

Results: Here, we show that hepatic miR-378 is positively regulated by TH. Transient overexpression of miR-378 in the liver of mice reduces serum cholesterol levels, accompanied with an increase in the expression of key enzymes in primary bile acid synthetic pathways and corresponding increases in biliary and fecal bile acid levels. Consistently, liver-specific miR-378 transgenic mice with moderate overexpression of hepatic miR-378 display decreased serum cholesterol levels and resistance to diet-induced hypercholesterolemia, while mice lacking miR-378 exhibit defects in bile acid and cholesterol homeostasis. Mechanistically, hepatic miR-378 regulates the expression of key enzymes in both classic and alternative bile acid synthetic pathways through MAFG, a transcriptional repressor, thereby modulating bile acid and cholesterol metabolism.

Conclusions: TH-responsive hepatic miR-378 is capable of modulating serum cholesterol levels by regulating both the classic and alternative BA synthetic pathways. Our study not only identifies a previously undescribed role of hepatic miR-378 but also provides new cholesterol-lowering approaches.

Should We Target Global Risk or Risk Factors?

PURPOSE OF REVIEW

Recent evidence has shaped the new guidelines for the management of dyslipidemia. The importance of accurate risk estimation, subclinical disease detection, and contemporary dyslipidemia management approaches are discussed in this review.

RECENT FINDINGS

Risk prediction helps determine the intensity of management strategies and identify high-risk patients. To overcome the pitfalls of the current risk prediction systems, incorporating genetic scores, biomarkers, and imaging is being explored. Key initiating event in atherogenesis is low-density lipoprotein cholesterol (LDL-C) retention in the arterial wall. Recent dyslipidemia guidelines agree that LDL-C is the primary target, but management approaches vary. Guidelines are shaped by new studies that show the benefits of high-intensity lipid lowering, especially for patients at very high-risk. Global risk assessment should be performed in all individuals for cardiovascular disease prevention. Main target should be the causal risk factors, particularly LDL-C which is one of the most important modifiable causal factors. Lower LDL-C goals will help prevent further events in very high-risk patients.

Relationship of serum vitamin D levels with coronary thrombus grade, TIMI flow, and myocardial blush grade in patients with acute ST-segment elevation myocardial infarction

BACKGROUND

Vitamin D deficiency is a prevalent condition that is found in about 30-50% of the general population, and it is increasing as a new risk factor for coronary artery disease. Our study aimed to evaluate the relationship of serum vitamin D levels with coronary thrombus burden, Thrombolysis In Myocardial Infarction flow grade, and myocardial blush grade in patients managed by primary percutaneous coronary intervention for their first acute ST-segment elevation myocardial infarction.

RESULTS

Eighty patients were included in the study with their first acute ST-segment elevation myocardial infarction and were managed by primary percutaneous coronary intervention. According to the serum concentrations of vitamin D, the study population was divided into 2 groups: group A with abnormal vitamin D levels less than 30 ng/ml (50 patients) and group B with normal vitamin D levels equal to or more than 30 ng/ml (30 patients). Angiographic data was recorded before and after coronary intervention. On comparing thrombus grade and initial and post-procedural Thrombolysis In Myocardial Infarction flow between both groups of patients, there was no significant difference (p = 0.327, p = 0.692, p = 0.397). However, myocardial blush grade was better in patients with normal vitamin D levels (p = 0.029) without a significant correlation between vitamin D concentration values and myocardial blush grade (r = 0.164, p = 0.146).

CONCLUSIONS

Patients with first acute ST-segment elevation myocardial infarction and normal vitamin D levels undergoing primary percutaneous coronary intervention had better myocardial blush grade and more successful microvascular reperfusion in comparison with patients with abnormal vitamin D levels. There was no significant difference between the normal and abnormal vitamin D groups regarding the coronary thrombus grade and Thrombolysis In Myocardial Infarction flow.