Elevated Levels of Apolipoprotein CIII Increase the Risk of Postprandial Hypertriglyceridemia

Exploring apolipoprotein C-III: pathophysiological and pharmacological relevance

The availability of pharmacological approaches able to effectively reduce circulating LDL cholesterol (LDL-C) has led to a substantial reduction in the risk of atherosclerosis-related cardiovascular disease (CVD). However, a residual cardiovascular (CV) risk persists in treated individuals with optimal levels of LDL-C. Additional risk factors beyond LDL-C are involved, and among these, elevated levels of triglycerides (TGs) and TG-rich lipoproteins are causally associated with an increased CV risk. Apolipoprotein C-III (apoC-III) is a key regulator of TG metabolism and hence circulating levels through several mechanisms including the inhibition of lipoprotein lipase activity and alterations in the affinity of apoC-III-containing lipoproteins for both the hepatic receptors involved in their removal and extracellular matrix in the arterial wall. Genetic studies have clarified the role of apoC-III in humans, establishing a causal link with CVD and showing that loss-of-function mutations in the APOC3 gene are associated with reduced TG levels and reduced risk of coronary heart disease. Currently available hypolipidaemic drugs can reduce TG levels, although to a limited extent. Substantial reductions in TG levels can be obtained with new drugs that target specifically apoC-III; these include two antisense oligonucleotides, one small interfering RNA and an antibody.

A bibliometric analysis and visualization of literature on non-fasting lipid research from 2012 to 2022

Background

Non-fasting lipid assessment can help predict cardiovascular disease risks and is linked to multiple diseases, particularly diabetes. The significance of non-fasting lipid levels in routine screening and postprandial lipid tests for potential dyslipidemia has not been conclusively determined. Various new lipid-lowering strategies have been developed to improve non-fasting dyslipidemia. Therefore, analysis of scientific outputs over the past decade is essential to reveal trends, hotspots, and frontier areas for future research in this field.

Methods

The Science Citation Index Expanded in the Web of Science Core Collection database was searched for publications related to non-fasting lipid research from 2012 to 2022. The regional distributions, authors, disciplines, journals, references, and keywords of the studies were analyzed using the bibliometric software VOSviewer and CiteSpace.

Results

A total of 4160 articles and reviews that met the inclusion criteria were included in this study. The output trend was established to be stable and the number of citation indices has been persistently increasing. A total of 104 countries/regions, 4668 organizations, and 20782 authors were involved in this research area. In terms of country, the United States had the largest number of publications (979). The University of Copenhagen was the most productive institution, publishing 148 papers. Professor Børge G Nordestgaard has made the most significant contribution to this field. Nutrients was the most productive journal while the American Journal of Clinical Nutrition was the highest co-cited journal. Analysis of co-cited references indicated that lipid-lowering strategies, statin therapy, high-fat meals, insulin resistance, physical exercise, and fructose were hotspots. Analysis of co-cited keywords revealed that apolipoprotein B, especially apolipoprotein B48, is becoming a key research focus. The keywords "gut microbiota" and "meal timing" were the most extensively studied.

Conclusion

The causal relationship between non-fasting dyslipidemia and diseases is currently being explored and the standards for non-fasting or postprandial lipid assessment are continuously being updated. Among the hotspots, lipid-lowering strategies are a potential research direction. Apolipoprotein B48, gut microbiota, and chrononutrition are the research frontiers. This initial bibliometric analysis of non-fasting lipids will enable researchers to monitor swift transformations and recognize novel concepts for upcoming research.

Combined association of triglyceride-glucose index and systolic blood pressure with all-cause and cardiovascular mortality among the general population

Background

The combined association of triglyceride-glucose (TyG) index and different systolic blood pressure (SBP) levels with all-cause and cardiovascular mortality among the general population remains unclear.

Methods

In this study, 6245 individuals were from the National Health and Nutrition Examination Survey (1999–2002). The study endpoints were all-cause and cardiovascular mortality. Multivariate Cox proportional hazards regression models were used to explore the combined association of TyG index and different SBP levels with all-cause and cardiovascular mortality.

Results

During a mean follow-up period of 66.8 months, a total of 284 all-cause deaths (331/100000 person-years) and 61 cardiovascular deaths (66/100000 person-years) were recorded. Multivariate Cox regression analysis revealed that the combination of low TyG index and low SBP (< 120 mmHg and < 130 mmHg) was associated with a reduced risk of all-cause and cardiovascular mortality than others. However, survival benefit was not observed in the combined group with the low TyG index and SBP < 140 mmHg. Furthermore, the mortality rate in the combined group of low TyG index and low SBP gradually increased with the elevation of SBP level.

Conclusion

The combination of low TyG index and low SBP (< 120 mmHg and < 130 mmHg) was associated with a lower risk of all-cause and cardiovascular mortality. However, no survival benefit was observed in the combined group of low TyG index and SBP < 140 mmHg.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03678-z.

Differentially Represented Proteins in Response to Infection with Mycobacterium tuberculosis Identified by Quantitative Serum Proteomics in Asian Elephants

Tuberculosis is a major global concern. Tuberculosis in wildlife is a risk for zoonotic transmission and becoming one of the challenges for conservation globally. In elephants, the number of cases is likely rising. The aim of this study was to identify proteins related to tuberculosis infection in elephants, which could then be used for the development of diagnostic tools and/or vaccines. A serum proteomics approach was used to characterize differentially represented proteins in response to Mycobacterium tuberculosis in Asian elephants (Elaphas maximus). Blood samples were collected from eight elephants, four of which were antibody positive for tuberculosis and four were antibody negative. Proteomics analysis identified 26 significantly dysregulated proteins in response to tuberculosis. Of these, 10 (38%) were identified as immunoglobulin and 16 (62%) as non-immunoglobulin proteins. The results provided new information on the antibody response to mycobacterial infection and biomarkers associated with tuberculosis and protective response to mycobacteria in Asian elephants. Protective mechanisms included defense against infection (Alpha-1-B glycoprotein A1BG, Serpin family A member 1 SERPINA1, Transthyretin TTR), neuroprotection (TTR), and reduced risks of inflammation, infections, and cancer (SERPINA1, Keratin 10 KRT10). Using a translational biotechnology approach, the results provided information for the identification of candidate diagnostic, prognostic, and protective antigens for monitoring and control of tuberculosis in Asian elephants.

Combined Oral Triglyceride and Glucose Tolerance Test After Acute Ischemic Stroke to Predict Recurrent Vascular Events: The Berlin “Cream&Sugar” Study

Background:

Elevated triglyceride and glucose levels are associated with an increased cardiovascular disease risk including ischemic stroke. It is not known whether the response to a combined oral triglyceride and glucose challenge after ischemic stroke improves identification of patients with increased risk for recurrent vascular events.

Methods:

The prospective, observational Berlin “Cream&Sugar” study was conducted at 3 different university hospital sites of the Charité–Universitätsmedizin Berlin, Germany, between January 24, 2009 and July 31, 2017. Patients with first-ever ischemic stroke were recruited 3 to 7 days after stroke. An oral triglyceride tolerance test (OTTT) and consecutive blood tests before (t 0 ) as well as 3 (t 1 ), 4 (t 2 ), and 5 hours (t 3 ) after OTTT were performed in fasting patients. An oral glucose tolerance test was performed in all nondiabetic patients 3 hours after the start of OTTT. Outcomes of the study were recurrent fatal or nonfatal stroke as well as a composite vascular end point including stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death assessed 1 year after stroke. Cox regression models were used to estimate hazard ratios and corresponding 95% CIs between patients with high versus low levels of triglyceride and glucose levels.

Results:

Overall 755 patients were included; 523 patients completed OTTT and 1-year follow-up. Patients were largely minor strokes patients with a median National Institutes of Health Stroke Scale score of 1 (0–3). Comparing highest versus lowest quartiles of triglyceride levels, neither fasting (adjusted hazard ratio t0 , 1.24 [95% CI, 0.45–3.42]) nor postprandial triglyceride levels (adjusted hazard ratio t3 , 0.44 [95% CI, 0.16–1.25]) were associated with recurrent stroke. With regard to recurrent vascular events, results were similar for fasting triglycerides (adjusted hazard ratio t0 , 1.09 [95% CI, 0.49–2.43]), however, higher postprandial triglyceride levels were significantly associated with a lower risk for recurrent vascular events (adjusted hazard ratio t3 , 0.42 [95% CI, 0.18–0.95]). No associations were observed between fasting and post–oral glucose tolerance test blood glucose levels and recurrent vascular risk. All findings were irrespective of the diabetic status of patients.

CONCLUSIONS:

In this cohort of patients with first-ever‚ minor ischemic stroke, fasting triglyceride or glucose levels were not associated with recurrent stroke at one year after stroke. However, higher postprandial triglyceride levels were associated with a lower risk of recurrent vascular events which requires further validation in future studies. Overall, our results do not support the routine use of a combined OTTT/oral glucose tolerance test to improve risk prediction for recurrent stroke.