Polygenic Risk of Hypertriglyceridemia Is Modified by BMI

Interplay between BMI, neutrophil, triglyceride and uric acid: a case-control study and bidirectional multivariate mendelian randomization analysis

BACKGROUND

This study aims to explore the interplay between body mass index (BMI), neutrophils, triglyceride levels, and uric acid (UA). Understanding the causal correlation between UA and health indicators, specifically its association with the body's inflammatory conditions, is crucial for preventing and managing various diseases.

METHODS

A retrospective analysis was conducted on 4,286 cases utilizing the Spearman correlation method. BMI, neutrophil count, and triglyceride levels were determined as key exposure factors. To further investigate the causal correlation, a two-sample Mendelian randomization(MR) design was utilized, leveraging data from genome-wide association study (GWAS). Within this framework, and multivariable Mendelian randomization(MVMR) was applied to explore the linkage between multiple genetic variants and complex traits.

RESULTS

The study primarily focused on UA, employing genetic variation as a natural tool to assess the causal impact of various factors on UA. Spearman correlation analysis revealed significant association between UA and BMI (ρ = 0.230,p<0.01), neutrophils (ρ = 0.164,p<0.01), and triglyceride levels (ρ = 0.154,p<0.01). Additionally, two-sample MR analysis affirmed a reciprocal causal association between neutrophils and UA (OR = 1.035,95%CI:1.009-1.061,p = 0.008), as well as positive causal connection between UA and both BMI (OR = 1.083,95%CI:1.042-1.126,p<0.001) and triglyceride levels (OR = 1.090,95%CI:1.037-1.146,p<0.001). Neutrophils also demonstrated a positive causal linkage with BMI (OR = 1.034,95%CI:1.009-1.078,p = 0.012) and triglyceride levels (OR = 1.077,95%CI:1.033-1.122,p<0.001), and BMI exhibited a similar causal association with triglyceride levels (OR = 1.300,95%CI:1.212-1.385,p<0.001). These findings shed light on the causal networks connecting UA, BMI, neutrophils, and triglyceride levels. By integrating Spearman correlation analysis with various MR study designs, this study provided a robust framework for identifying key factors influencing hyperuricemia and related health issues, thereby enhancing our understanding of the interplay between inflammatory markers and these health indicators.

CONCLUSIONS

Our study presents strong evidence of the complex interconnection between BMI, neutrophils, triglyceride, and UA, revealing complex causal links and highlighting potential inflammatory states as key mediators. The findings may contribute to a better understanding of these factors and potentially lead to improved clinical outcomes and patients' health.

DNA methylation levels may contribute to severe hypertriglyceridemia in multifactorial chylomicronemia syndrome

BACKGROUND AND AIMS

Familial chylomicronemia syndrome (FCS) and multifactorial chylomicronemia syndrome (MCS) are the two main causes of severe hypertriglyceridemia (sHTG). FCS is a rare autosomal recessive form of sHTG, whereas MCS is mainly polygenic in nature with both common and rare variants accumulating and leading to sHTG. However, 30 to 50% of MCS patients have no identified genetic cause of sHTG. DNA methylation (DNAm) is a non-traditional heritable factor known to be associated with triglyceride (TG) levels. The aim of this study is to determine if DNAm level at three candidate genes for hypertriglyceridemia (ABCG1, CPT1A and SREBF1) could contribute to sHTG in MCS patients.

METHODS

A total of 114 MCS and 20 FCS patients were included in this retrospective study. DNAm levels were measured at ABCG1 (cg06500161), CPT1A (cg00574958), and SREBF1 (cg11024682) gene loci using pyrosequencing of bisulfite-treated DNA.

RESULTS

DNAm levels at ABCG1, CPT1A and SREBF1 were significantly associated with TG levels or minimal TG levels in MCS patients. Prevalence of patients with at least 2 loci with DNAm levels into the top tertile of DNAm associated with hypertriglyceridemia was significantly higher in MCS patients with genetically undefined sHTG compared to MCS patients with polygenic sHTG and FCS patients (57 % vs. 24 % vs. 0 %, respectively; p < 0.0001).

CONCLUSION

This study suggests for the first time that DNAm could contribute to sHTG in MCS patients. It suggests that further studies of epivariations may contribute to better understand the clinical heterogeneity seen in MCS patients.

Polygenic Risk Score, Cardiorespiratory Fitness, and Cardiometabolic Risk Factors: WASEDA'S Health Study

PURPOSE

This study estimated an individual's genetic liability to cardiometabolic risk factors by polygenic risk score (PRS) construction and examined whether high cardiorespiratory fitness (CRF) modifies the association between PRS and cardiometabolic risk factors.

METHODS

This cross-sectional study enrolled 1296 Japanese adults aged ≥40 yr. The PRS for each cardiometabolic trait (blood lipids, glucose, hypertension, and obesity) was calculated using the LDpred2 and clumping and thresholding methods. Participants were divided into low-, intermediate-, and high-PRS groups according to PRS tertiles for each trait. CRF was quantified as peak oxygen uptake (V̇O 2peak ) per kilogram body weight. Participants were divided into low-, intermediate-, and high-CRF groups according to the tertile V̇O 2peak value.

RESULTS

Linear regression analysis revealed a significant interaction between PRS for triglyceride (PRS TG ) and CRF groups on serum TG levels regardless of the PRS calculation method, and the association between PRS TG and TG levels was attenuated in the high-CRF group. Logistic regression analysis revealed a significant sub-additive interaction between LDpred2 PRS TG and CRF on the prevalence of high TG, indicating that high CRF attenuated the genetic predisposition to high TG. Furthermore, a significant sub-additive interaction between PRS for body mass index and CRF on obesity was detected regardless of the PRS calculation method. These significant interaction effects on high TG and obesity were diminished in the sensitivity analysis using V̇O 2peak per kilogram fat-free mass as the CRF index. Effects of PRSs for other cardiometabolic traits were not significantly attenuated in the high-CRF group regardless of PRS calculation methods.

CONCLUSIONS

The findings of the present study suggest that individuals with high CRF overcome the genetic predisposition to high TG levels and obesity.

Acute pancreatitis risk in multifactorial chylomicronemia syndrome depends on the molecular cause of severe hypertriglyceridemia

BACKGROUND AND AIMS

Multifactorial chylomicronemia syndrome (MCS) is a severe form of hypertriglyceridemia (hyperTG) associated with an increased risk of acute pancreatitis (AP). Severe hyperTG is mainly polygenic in nature, either caused by the presence of heterozygous pathogenic variants (PVs) in TG-related metabolism genes or by accumulation of common variants in hyperTG susceptibility genes. This study aims to determine if the risk of AP is similar amongst MCS patients with different molecular causes of severe hyperTG.

METHODS

This study included 114 MCS patients who underwent genetic testing for PVs in TG-related metabolism genes and 16 single nucleotide polymorphisms (SNPs) in hyperTG susceptibility genes. A weighted TG-polygenic risk score (TG-PRS) was calculated. A TG-PRS score ≥ 90th percentile was used to define a high TG-PRS.

RESULTS

Overall, 66.7% of patients had severe hyperTG of polygenic origin. MCS patients with only a PV and those with both a PV and high TG-PRS were more prone to have maximal TG concentration ≥ 40 mmol/L (OR 5.33 (1.55-18.36); p = 0.008 and OR 5.33 (1.28-22.25); p = 0.02), as well as higher prevalence of AP (OR 3.64 (0.89-14.92); p = 0.07 and OR 11.90 (2.54-55.85); p = 0.002) compared to MCS patients with high TG-PRS alone.

CONCLUSIONS

This is the first study to show that MCS caused by a high TG-PRS and a PV is associated with higher risk of AP, similar to what is seen in the monogenic form of severe hyperTG. This suggests that determining the molecular cause of severe hyperTG could be useful to stratify the risk of pancreatitis in MCS.

Developing a model to predict the early risk of hypertriglyceridemia based on inhibiting lipoprotein lipase (LPL): a translational study

Hypertriglyceridemia (HTG) is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD). One of the multiple origins of HTG alteration is impaired lipoprotein lipase (LPL) activity, which is an emerging target for HTG treatment. We hypothesised that early, even mild, alterations in LPL activity might result in an identifiable metabolomic signature. The aim of the present study was to assess whether a metabolic signature of altered LPL activity in a preclinical model can be identified in humans. A preclinical LPL-dependent model of HTG was developed using a single intraperitoneal injection of poloxamer 407 (P407) in male Wistar rats. A rat metabolomics signature was identified, which led to a predictive model developed using machine learning techniques. The predictive model was applied to 140 humans classified according to clinical guidelines as (1) normal, less than 1.7 mmol/L; (2) risk of HTG, above 1.7 mmol/L. Injection of P407 in rats induced HTG by effectively inhibiting plasma LPL activity. Significantly responsive metabolites (i.e. specific triacylglycerols, diacylglycerols, phosphatidylcholines, cholesterol esters and lysophospholipids) were used to generate a predictive model. Healthy human volunteers with the impaired predictive LPL signature had statistically higher levels of TG, TC, LDL and APOB than those without the impaired LPL signature. The application of predictive metabolomic models based on mechanistic preclinical research may be considered as a strategy to stratify subjects with HTG of different origins. This approach may be of interest for precision medicine and nutritional approaches.

Pan-Cancer Profiling and Digital Pathology Analysis Reveal Negative Prognostic Biomarker ZPR1 Associated with Immune Infiltration and Treatment Response in Hepatocellular Carcinoma

Purpose

ZPR1 is a zinc finger-containing protein that plays a crucial role in neurodegenerative diseases, lipid metabolism disorders, and non-alcoholic fatty liver disease. However, the expression pattern, prognostic value, and treatment response of ZPR1 in pan-cancer and hepatocellular carcinoma (HCC) remain unclear.

Patients and Methods

Pan-cancer expression profiles and relevant clinical data were acquired from UCSC Xena platform. Pan-cancer expression, epigenetic profile, and clinical correlation analysis for ZPR1 were performed. We next explored the prognostic significance and potential biological functions of ZPR1 in HCC. Furthermore, the relationship between ZPR1 and immune infiltration and treatment response was investigated. Finally, quantitative immunohistochemistry (IHC) analysis was applied to assess the correlation of ZPR1 expression and immune microenvironment in HCC tissues using Qupath software.

Results

ZPR1 was differentially expressed in most tumor types and significantly up-regulated in HCC. ZPR1 showed hypo-methylated status in most tumors. Pan-cancer correlation analysis indicated that ZPR1 was closely associated with clinicopathological factors and TMB, MSI, and stemness index in HCC. High ZPR1 expression could be an independent risk factor for adverse prognosis in HCC. ZPR1 correlated with immune cell infiltration and therapeutic response. Finally, IHC results suggested that ZPR1 correlated with CD4, CD56, CD68, and PD-L1 expression and is a promising pathological diagnostic marker in HCC.

Conclusion

Immune infiltrate-associated ZPR1 could be considered a novel negative prognostic biomarker for therapeutic response in HCC.

Development of LXR inverse agonists to treat MAFLD, NASH, and other metabolic diseases

Activation of LXR activity by synthetic agonists has been the focus of many drug discovery efforts with a focus on treatment of dyslipidemia and atherosclerosis. Many agonists have been developed, but all have been hindered due to their ability to efficaciously stimulate de novo lipogenesis. Here, we review the development of LXR inverse agonists that were originally optimized for their ability to enable recruitment of corepressors leading to silencing of genes that drive de novo lipogenesis. Such compounds have efficacy in animal models of MAFLD, dyslipidemia, and cancer. Several classes of LXR inverse agonists have been identified and one is now in clinical trials for treatment of severe dyslipidemia.