Association of Lipid Fractions With Risks for Coronary Artery Disease and Diabetes

Favourable HDL composition in endurance athletes is not associated with changes in HDL in vitro antioxidant and endothelial anti-inflammatory function

Given the failure of high-density lipoprotein (HDL) raising therapies to reduce cardiovascular disease risk, attention has turned towards HDL composition and vascular protective functions. In individuals with insulin resistance, exercise interventions recover HDL function. However, the effect of exercise on HDL in otherwise healthy individuals is unknown. This cross-sectional study aimed to measure HDL composition and antioxidant/endothelial anti-inflammatory function in insulin sensitive endurance athlete and healthy control men. HDL was isolated using density gradient ultracentrifugation. HDL composition was measured using microplate assays for apolipoprotein A-I, total cholesterol content and apolipoprotein M. HDL protein composition was measured using nano-liquid chromatography tandem mass spectrometry. HDL subclass distribution was measured by native gel electrophoresis. HDL in vitro antioxidant function was measured by paraoxonase-1 activity assay and anti-inflammatory function assessed in endothelial cells. Compared with controls, endurance athlete HDL had higher apolipoprotein A-1 (1.65 ± 0.62 mg/ml vs 1.21 ± 0.34 mg/ml, P=0.028) and higher total cholesterol content (2.09 ± 0.44 mmol/L vs 1.54 ± 0.33 mmol/L, P<0.001). Proteomics revealed higher apolipoprotein A-II, A-IV and D and transthyretin in endurance athlete HDL versus controls. There was no difference observed in in vitro HDL antioxidant or anti-inflammatory functions between controls and endurance athletes. Despite a more favourable composition, endurance athlete HDL did not have higher in vitro antioxidant or anti-inflammatory function. It is possible that HDL has a ceiling of function, i.e. that healthy HDL function cannot be enhanced by endurance exercise.

Causal inference in health and disease: a review of the principles and applications of Mendelian randomization

Mendelian randomization (MR) is a genetic epidemiological technique that uses genetic variation to infer causal relationships between modifiable exposures and outcome variables. Conventional observational epidemiological studies are subject to bias from a range of sources; MR analyses can offer an advantage in that they are less prone to bias as they use genetic variants inherited at conception as "instrumental variables", which are proxies of an exposure. However, as with all research tools, MR studies must be carefully designed to yield valuable insights into causal relationships between exposures and outcomes, and to avoid biased or misleading results that undermine the validity of the causal inferences drawn from the study. In this review, we outline Mendel's laws of inheritance, the assumptions and principles that underlie MR, MR study designs and methods, and how MR analyses can be applied and reported. Using the example of serum phosphate concentrations on liability to kidney stone disease we illustrate how MR estimates may be visualized and, finally, we contextualize MR in bone and mineral research including exemplifying how this technique could be employed to inform clinical studies and future guidelines concerning BMD and fracture risk. This review provides a framework to enhance understanding of how MR may be used to triangulate evidence and progress research in bone and mineral metabolism as we strive to infer causal effects in health and disease.

Discordance Analysis of VLDL-C and ApoB in UK Biobank and Framingham Study: A Prospective Observational Study

BACKGROUND

Recent observational and Mendelian randomization analyses have reported significant effects of VLDL-C (very-low density lipoprotein cholesterol) on risk that is independent of ApoB (apolipoprotein B). We aim to determine the independent association of VLDL-C and ApoB with the risk of new onset cardiovascular events in the UK Biobank and Framingham Heart Study cohorts.

METHODS

We included 294 289 UK Biobank participants with a median age of 56 years, 42% men, and 2865 Framingham Heart Study participants (median age, 53 years; 47% men). The residual resulting from regressing VLDL-C on ApoB expresses the portion of VLDL-C not explained by ApoB, while the residual from regressing ApoB on VLDL-C expresses the portion of ApoB not explained by VLDL-C. Cox proportional hazards models for atherosclerotic cardiovascular disease incidence were created for residual VLDL-C and residual ApoB. Models were analyzed with and without high-density lipoprotein cholesterol (HDL-C). Furthermore, we investigated the independent effects of VLDL-C after accounting for ApoB and HDL-C and of HDL-C after accounting for ApoB and VLDL-C.

RESULTS

In the UK Biobank, ApoB was highly correlated with VLDL-C (r=0.70; P<0.001) but weakly negatively correlated with HDL-C (r=-0.11; P<0.001). The ApoB residual and the VLDL-C residual were significantly associated with new-onset atherosclerotic cardiovascular disease (hazard ratio [HR], 1.08 and 1.05, respectively; P<0.001). After adjusting for HDL-C, the ApoB residual remained similar in magnitude (HR, 1.10; P<0.001), whereas the effect size of the VLDL-C residual was reduced (HR, 1.02; P=0.029). The independent effect of HDL-C (after accounting for ApoB and VLDL-C) remained robust (HR, 0.86; P<0.0001), while the independent effect of VLDL-C (after accounting for ApoB and HDL-C) was modest (HR, 1.02; P=0.029). All results were consistent in the Framingham cohort.

CONCLUSIONS

When adjusted for HDL-C, the association of VLDL-C with cardiovascular risk was no longer clinically meaningful. Our residual discordance analysis suggests that adjustment for HDL-C cannot be ignored.

Differences in HDL-related coronary heart disease risk between individuals with and without diabetes

BACKGROUND AND AIMS

High-density lipoprotein (HDL) might lose atheroprotective functions in the presence of diabetes. We sought to examine associations of HDL cholesterol (HDL-C) and HDL particle (HDL-P) subclasses with risk of coronary heart disease (CHD) stratified by diabetes.

METHODS

We included 393,516 participants (20,691 diabetics and 372,825 nondiabetics) from the UK Biobank. Restricted cubic splines cooperated with Cox model were used to estimate associations of HDL with CHD.

RESULTS

During a median follow-up of 13.0 years, 3398 (16.4 %) and 24,772 (6.6 %) incident CHD events occurred among diabetics and nondiabetics, respectively. HDL-C showed inverse associations with CHD among nondiabetics, whereas U-shaped associations among diabetics. Compared to individuals with normal HDL-C (40th - 60th percentile, 1.32-1.51 mmol/L), those in the top percentile (95th, >2.16 mmol/L) had lower CHD risks among nondiabetics (Hazard Ratio, 0.79; 95 % confidence interval, 0.73-0.86), but higher risks among diabetics (1.38, 1.02-1.88). As for HDL-P, there were inverted U-shaped associations of very large HDL-P and linearly negative associations of large HDL-P with CHD among nondiabetics; however, linearly positive associations of very large HDL-P and null associations of large HDL were observed among diabetics. L-shaped associations of medium and small HDL-P were found both in diabetics and nondiabetics.

CONCLUSIONS

Very high HDL-C levels were associated with lower CHD risks in nondiabetics, but higher risks in diabetics. Smaller HDL-P was negatively, whereas very large HDL-P was positively associated with CHD risk in diabetics. These data advance our knowledge about the interactions between HDL and diabetes.

Physical activity and the risk of developing 8 age-related diseases: epidemiological and Mendelian randomization studies

BACKGROUND

We aimed to characterize the associations between physical activity levels and the risk of developing age-related diseases in the Coronary Artery Risk Development in Young Adults (CARDIA) study and used Mendelian randomization (MR) to assess whether there are causal relationships between physical activity levels and the risk of developing 8 age-related diseases (coronary atherosclerosis, ischemic heart disease, angina, Alzheimer's disease, hypertension, type 2 diabetes, hyperlipidemia, and venous thromboembolism).

METHODS

Based on the data available in the CARDIA, we obtained data related to five disease states: coronary heart disease, hypertension, diabetes, hyperlipidemia, and venous thromboembolism. Binary logistic regression analysis estimated the multivariable-adjusted associations between different physical activity statuses and diseases. For the MR study, we used summary-level data from a recently published genome-wide association study on physical activity (including vigorous physical activity and accelerometer-based physical activity) conducted with participants from the UK Biobank study. We selected the above 8 age-related diseases as our outcomes.

RESULTS

In the CARDIA-based analysis, the risk of developing coronary heart disease [OR (95% CI): 0.562 (0.397-0.795)], hypertension [OR (95% CI): 0.703 (0.601-0.821)], diabetes [OR (95% CI): 0.783 (0.620-0.988)], and hyperlipidemia [OR (95% CI): 0.792 (0.662-0.949)] was negatively related to physical activity status when participants achieved the physical activity target. Our MR results support a negative causal association between genetically determined vigorous physical activity levels and the risk of developing 3 age-related diseases, namely, angina, hypertension and type 2 diabetes. Moreover, our results also support a negative causal association between genetically determined accelerometer-based physical activity levels and the risk of developing angina.

CONCLUSIONS

Promotion of physical activity is likely to prevent specific age-related diseases.

Interaction Between Primary Hyperlipidemias and Type 2 Diabetes: Therapeutic Implications

There is a gap of knowledge about the clinical and pathophysiological implications resulting from the interaction between primary hyperlipidemias and type 2 diabetes (T2D). Most of the existing evidence comes from sub-analyses of cohorts; scant information derives from randomized clinical trials. The expected clinical implications of T2D in patients with primary hyperlipidemias is an escalation of their already high cardiovascular risk. There is a need to accurately identify patients with this dual burden and to adequately prescribe lipid-lowering therapies, with the current advancements in newer therapeutic options. This review provides an update on the interactions of primary hyperlipidemias, such as familial combined hyperlipidemia, familial hypercholesterolemia, multifactorial chylomicronemia, lipoprotein (a), and type 2 diabetes.

Lipids, Apolipoproteins, Lipid-Lowering Drugs, and the Risk of Cerebral Small Vessel Disease: A Mendelian Randomization Study

BACKGROUND

Serum lipids are causally involved in the occurrence of atherosclerosis, but their roles in cerebral small vessel disease remain unclear. This study aimed to investigate the causal roles of lipid or apolipoprotein traits in cerebral small vessel disease and to determine the effects of lipid-lowering interventions on this disease.

METHODS AND RESULTS

Data on genetic instruments of lipids/apolipoproteins, as well as characteristic cerebral small vessel disease manifestations, including small vessel stroke (SVS) and white matter hyperintensity (WMH), were obtained from publicly genome-wide association studies. Through 2-sample Mendelian randomization analyses, it was found that decreased levels of high-density lipoprotein cholesterol (odds ratio [OR], 0.85, P=0.007) and apolipoprotein A-I (OR, 0.83, P=0.005), as well as increased level of triglycerides (OR, 1.16, P=0.025) were associated with a higher risk of SVS. A low level of high-density lipoprotein cholesterol (OR, 0.93, P=0.032) was associated with larger WMH volume. Specifically, the genetically determined expressions of lipid fractions in various size-defined lipoprotein particles were more closely related to the risk of SVS than WMH. Moreover, it was found that the hypertension trait ranked at the top in mediating the causal effect of hyperlipidemia on SVS and WMH by using Mendelian randomization-based mediation analysis. For drug-target Mendelian randomization, the low-density lipoprotein cholesterol-reducing genetic variation alleles at HMGCR and NL1CL1 genes and the high-density lipoprotein cholesterol-raising genetic variation alleles at the CETP gene were predicted to decrease the risk of SVS.

CONCLUSIONS

The present Mendelian randomization study indicates that genetically determined hyperlipidemia is closely associated with a higher risk of cerebral small vessel disease, especially SVS. Lipid-lowering drugs could be potentially considered for the therapies and preventions of SVS rather than WMH.

A metabolome-wide Mendelian randomization study prioritizes causal circulating metabolites for reproductive disorders including primary ovarian insufficiency, polycystic ovary syndrome, and abnormal spermatozoa

BACKGROUND

Accumulating studies have highlighted the significant role of circulating metabolomics in the etiology of reproductive system disorders. However, the causal effects between genetically determined metabolites (GDMs) and reproductive diseases, including primary ovarian insufficiency (POI), polycystic ovary syndrome (PCOS), and abnormal spermatozoa (AS), still await thorough clarification.

METHODS

With the currently most comprehensive genome-wide association studies (GWAS) data of metabolomics, systematic two-sample Mendelian randomization (MR) analyses were conducted to disclose causal associations between 1,091 blood metabolites and 309 metabolite ratios with reproductive disorders. The inverse-variance weighted (IVW) method served as the primary analysis approach, and multiple effective MR methods were employed as complementary analyses including MR-Egger, weighted median, constrained maximum likelihood (cML-MA), contamination mixture method, robust adjusted profile score (MR-RAPS), and debiased inverse-variance weighted method. Heterogeneity and pleiotropy were assessed via MR-Egger intercept and Cochran's Q statistical analysis. Outliers were detected by Radial MR and MR-PRESSO methods. External replication and metabolic pathway analysis were also conducted.

RESULTS

Potential causal associations of 63 GDMs with POI were unearthed, and five metabolites with strong causal links to POI were emphasized. Two metabolic pathways related to the pathogenesis of POI were pinpointed. Suggestive causal effects of 70 GDMs on PCOS were detected, among which 7 metabolites stood out for strong causality with elevated PCOS risk. Four metabolic pathways associated with PCOS mechanisms were recognized. For AS, 64 GDMs as potential predictive biomarkers were identified, particularly highlighting two metabolites for their strong causal connections with AS. Three pathways underneath the AS mechanism were identified. Multiple assessments were conducted to further confirm the reliability and robustness of our causal inferences.

CONCLUSION

By extensively assessing the causal implications of circulating GDMs on reproductive system disorders, our study underscores the intricate and pivotal role of metabolomics in reproductive ill-health, laying a theoretical foundation for clinical strategies from metabolic insights.

Remnant cholesterol is more positively related to diabetes, prediabetes, and insulin resistance than conventional lipid parameters and lipid ratios: A multicenter, large sample survey

BACKGROUND

Not many large-sample investigations are available that compare the potency of the relationship of remnant cholesterol (RC) and other lipid parameters with diabetes and prediabetes. The goals of our study are to discover the relationship between RC and prediabetes, diabetes, and insulin resistance (IR) and to investigate RC, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), TC/HDL-C, LDL-C/HDL-C, and TG/HDL-C, which are the lipid parameters that are most positively related to diabetes, prediabetes, and IR.

METHODS

This research enrolled 36 684 subjects from China's eight provinces. We employed multiple logistic regression analysis for testing the relationship between lipid parameters and diabetes, prediabetes, and IR.

RESULTS

After adjusting for potential confounders, and comparing the results with other lipid parameters, the positive relationship between RC and diabetes (odds ratio [OR] 1.417, 95% confidence interval [CI]: 1.345-1.492), prediabetes (OR 1.555, 95% CI: 1.438-1.628), and IR (OR 1.488, 95% CI: 1.404-1.577) was highest. RC was still related to diabetes, prediabetes, and IR even when TG <2.3 mmol/L (diabetes: OR 1.256, 95% CI: 1.135-1.390; prediabetes: OR 1.503, 95% CI: 1.342-1.684; and IR: OR 1.278, 95% CI: 1.140-1.433), LDL-C <2.6 mmol/L (diabetes: OR 1.306, 95% CI: 1.203-1.418; prediabetes: OR 1.597, 95% CI: 1.418-1.798; and IR: OR 1.552, 95% CI: 1.416-1.701), or HDL-C ≥1 mmol/L (diabetes: OR 1.456, 95% CI: 1.366-1.550; prediabetes: OR 1.553, 95% CI: 1.421-1.697; and IR: OR 1.490, 95% CI: 1.389-1.598).

CONCLUSION

RC is more positively related to diabetes, prediabetes, and IR than conventional lipids and lipid ratios in the general population, the relationships between RC and diabetes, prediabetes, and IR are stable, even if HDL-C, LDL-C, or TG are at appropriate levels.

How safe are proprotein convertase subtilisinekexin type 9 inhibitors in diabetes?

PURPOSE OF REVIEW

To examine the safety of proprotein convertase subtilisinekexin type 9 (PCSK9) inhibitors in patients with diabetes, specifically focusing on their impact on glucose metabolism.

RECENT FINDINGS

Patients with diabetes often require intensified lipid-lowering therapy. PCSK9 inhibitors can reduce low-density lipoprotein cholesterol (LDL-C) concentrations by approximately 60%, and significantly reduce cardiovascular risk when added to statin therapy. Some studies have suggested an association between low LDL-C levels and an increased risk of new-onset diabetes, and genetics has almost consistently shown an increased glucose concentration and risk of diabetes. Most clinical trials have not demonstrated a deterioration in glycaemic control in patients with diabetes after the use of PCSK9 inhibitors, and they do not lead to other significant treatment-emergent adverse events.

SUMMARY

Although the majority of patients with diabetes are undergoing background statin therapy, which may mask potential adverse effects of PCSK9 inhibitors on glycaemic control, current data suggest that the benefits outweigh the risks for diabetic patients using PCSK9 inhibitors. Considering the different nature of genetic studies and of clinical trials, close monitoring of glucose parameters is necessary, especially in individuals with prediabetes.

A plant-based diet index to study the relation between diet and disease risk among adults: a narrative review

Plant-based diets (PBD) may offer various health benefits and contribute to a sustainable way of life, but, if not planned correctly, may also confer risks, e.g., by focusing on plant foods with low nutrient density, such as foods primarily consisting of refined carbohydrates. A plant-based diet index (PDI) differentiating between a healthful, unhealthful, and overall PBD, offers a promising approach to standardize and compare studies and integrate results. In this review we (1) summarize current evidence on the PDI and disease risk of relevance to public health, (2) discuss the methodology of the PDI and how it can be sensibly applied in further studies and (3) indicate areas with a lack of knowledge, such as vulnerable populations. In summary, our amalgamation shows, that adherence to a healthier plant-based diet is associated with an 8-68% lower risk for metabolic risk factors, diabetes, and cardiovascular disease, while adherence to an unhealthier plant-based diet is associated with a 10-63% higher risk. Although differences in calculation methods and underlying diet patterns between populations should be accounted for, the PDI can be a useful tool to assess adherence to different plant-based diet patterns and their association with health outcomes in cohort studies across cultures.

A combined observational and Mendelian randomization investigation reveals NMR-measured analytes to be risk factors of major cardiovascular diseases

Dyslipidaemias is the leading risk factor of several major cardiovascular diseases (CVDs), but there is still a lack of sufficient evidence supporting a causal role of lipoprotein subspecies in CVDs. In this study, we comprehensively investigated several lipoproteins and their subspecies, as well as other metabolites, in relation to coronary heart disease (CHD), heart failure (HF) and ischemic stroke (IS) longitudinally and by Mendelian randomization (MR) leveraging NMR-measured metabolomic data from 118,012 UK Biobank participants. We found that 123, 110 and 36 analytes were longitudinally associated with myocardial infarction, HF and IS (FDR < 0.05), respectively, and 25 of those were associated with all three outcomes. MR analysis suggested that genetically predicted levels of 70, 58 and 7 analytes were associated with CHD, HF and IS (FDR < 0.05), respectively. Two analytes, ApoB/ApoA1 and M-HDL-C were associated with all three CVD outcomes in the MR analyses, and the results for M-HDL-C were concordant in both observational and MR analyses. Our results implied that the apoB/apoA1 ratio and cholesterol in medium size HDL were particularly of importance to understand the shared pathophysiology of CHD, HF and IS and thus should be further investigated for the prevention of all three CVDs.

Nonlinear relationship between high-density lipoprotein cholesterol and cardiovascular disease: an observational and Mendelian randomization analysis

BACKGROUND

Clinical trials and Mendelian randomization (MR) studies reported null effects of high-density lipoprotein cholesterol (HDL-C) on risk of cardiovascular disease (CVD), which might have overlooked a nonlinear causal association. We aimed to investigate the dose-response relationship between circulating HDL-C concentrations and CVD in observational and MR frameworks.

METHODS

We included 348,636 participants (52,919 CVD cases and 295,717 non-cases) of European ancestry with genetic data from the UK Biobank (UKB) and acquired genome-wide association summary data for HDL-C of Europeans from the Global Lipids Genetics Consortium (GLGC). Observational analyses were conducted in the UKB. Stratified MR analyses were conducted combing genetic data for CVD from UKB and lipids from GLGC.

RESULTS

Observational analyses showed L-shaped associations of HDL-C with CVD, with no further risk reduction when HDL-C levels exceeded 70 mg/dL. Multivariable MR analyses across entire distribution of HDL-C found no association of HDL-C with CVD, after control of the pleiotropic effect on other lipids and unmeasured pleiotropism. However, in stratified MR analyses, significant inverse associations of HDL-C with CVD were observed in the stratum of participants with HDL-C ≤ 50 mg/dL (odds ratio per unit increase, 0.86; 95 % confidence interval, 0.79-0.94), while null associations were observed in any stratum above 50 mg/dL.

CONCLUSIONS

Our data suggest a potentially causal inverse association of HDL-C at low levels with CVD risks. These findings advance our knowledge about the role of HDL as a potential target in CVD prevention and therapy.

Non-targeted metabolomics revealed novel links between serum metabolites and primary ovarian insufficiency: a Mendelian randomization study

Background

Primary ovarian insufficiency (POI) is a common clinical endocrine disorder with a high heterogeneity in both endocrine hormones and etiological phenotypes. However, the etiology of POI remains unclear. Herein, we unraveled the causality of genetically determined metabolites (GDMs) on POI through Mendelian randomization (MR) study with the overarching goal of disclosing underlying mechanisms.

Methods

Genetic links with 486 metabolites were retrieved from GWAS data of 7824 European participants as exposures, while GWAS data concerning POI were utilized as the outcome. Via MR analysis, we selected inverse-variance weighted (IVW) method for primary analysis and several additional MR methods (MR-Egger, weighted median, and MR-PRESSO) for sensitivity analyses. MR-Egger intercept and Cochran's Q statistical analysis were conducted to assess potential heterogeneity and pleiotropy. In addition, genetic variations in the key target metabolite were scrutinized further. We conducted replication, meta-analysis, and linkage disequilibrium score regression (LDSC) to reinforce our findings. The MR Steiger test and reverse MR analysis were utilized to assess the robustness of genetic directionality. Furthermore, to deeply explore causality, we performed colocalization analysis and metabolic pathway analysis.

Results

Via IVW methods, our study identified 33 metabolites that might exert a causal effect on POI development. X-11437 showed a robustly significant relationship with POI in four MR analysis methods (P IVW=0.0119; P weighted-median =0.0145; PMR-Egger =0.0499; PMR-PRESSO =0.0248). Among the identified metabolites, N-acetylalanine emerged as the most significant in the primary MR analysis using IVW method, reinforcing its pivotal status as a serum biomarker indicative of an elevated POI risk with the most notable P-value (P IVW=0.0007; PMR-PRESSO =0.0022). Multiple analyses were implemented to further demonstrate the reliability and stability of our deduction of causality. Reverse MR analysis did not provide evidence for the causal effects of POI on 33 metabolites. Colocalization analysis revealed that some causal associations between metabolites and POI might be driven by shared genetic variants.

Conclusion

By incorporating genomics with metabolomics, this study sought to offer a comprehensive analysis in causal impact of serum metabolome phenotypes on risks of POI with implications for underlying mechanisms, disease screening and prevention.

Non-linear associations of atherogenic index of plasma with prediabetes and type 2 diabetes mellitus among Chinese adults aged 45 years and above: a cross-sectional study from CHARLS

Background

Dyslipidemia is strongly associated with the development of prediabetes and type 2 diabetes mellitus (T2DM). The atherogenic index of plasma (AIP), as a comprehensive index for assessing lipid metabolism, has received extensive attention from researchers in recent years. However, there are relatively few studies exploring the relationships between AIP and the risk of prediabetes and T2DM in the Chinese population. This study focuses on exploring the relationships of AIP with the risk of prediabetes and T2DM in the Chinese population.

Methods

We conducted an analysis of the public data from the China Health and Retirement Longitudinal Study (CHARLS), involving a total of 12,060 participants aged 45 years and above in China. The study explored the relationships of AIP with prediabetes and T2DM risk through multivariate logistic regression, subgroup analysis, smooth curve fitting, and threshold effect analysis.

Results

After adjusting for potential confounding factors, we observed positive associations between AIP and the risk of prediabetes [odds ratio (OR) = 1.75, 95% confidence interval (CI): 1.49-2.06] and T2DM (OR = 2.91, 95% CI: 2.38-3.57). Participants with higher AIP levels demonstrated a significantly elevated risk of prediabetes (OR = 1.52, 95% CI: 1.33-1.74) and T2DM (OR = 2.28, 95% CI: 1.92-2.71) compared to those with lower AIP levels. AIP showed consistent correlations with prediabetes and T2DM risk in different subgroups. The results showed the non-linear relationships between AIP and risk of prediabetes and T2DM, with inflection points at 0.29 and -0.04, respectively. When AIP > 0.29, there was a positive association between AIP and the risk of prediabetes (OR = 2.24, 95% CI: 1.67-3.00, p < 0.0001). Similarly, when AIP > -0.04, AIP was positively associated with the risk of T2DM (OR = 3.33, 95% CI: 2.67-4.16, p < 0.0001).

Conclusions

This study demonstrated non-linear positive associations of AIP with the risk of prediabetes and T2DM among participants ≥ 45 years of age in China.

Blood lipid profile, HbA1c, fasting glucose, and diabetes: a cohort study and a two-sample Mendelian randomization analysis

PURPOSE

The prevalence of diabetes is increasing worldwide. The associations between the lipid profile and glycated hemoglobin (HbA1c), fasting glucose, and diabetes remain unclear, so we aimed to perform a cohort study and a two-sample Mendelian randomization (MR) study to investigate the causality between blood lipid profile and HbA1c, fasting glucose, and diabetes.

METHODS

A total of 25,171 participants from the Taiwan Biobank were enrolled. We applied a cohort study and an MR study to assess the association between blood lipid profile and HbA1c, fasting glucose, and diabetes. The summary statistics were obtained from the Asian Genetic Epidemiology Network (AGEN), and the estimates between the instrumental variables (IVs) and outcomes were calculated using the inverse-variance weighted (IVW) method. A series of sensitivity analyses were performed.

RESULTS

In the cohort study, high-density lipoprotein cholesterol (HDL-C) was negatively associated with HbA1c, fasting glucose, and diabetes, while the causal associations between HDL-C and HbA1c (βIVW = - 0.098, p = 0.003) and diabetes (βIVW = - 0.594, p < 0.001) were also observed. Furthermore, there was no pleiotropy effect in this study using the MR-Egger intercept test and MR-PRESSO global test.

CONCLUSIONS

Our results support the hypothesis that a genetically determined increase in HDL-C is causally related to a reduction in HbA1c and a lower risk of diabetes.

A two-sample Mendelian randomization study explores metabolic profiling of different glycemic traits

We assessed the causal relation of four glycemic traits and type 2 diabetes liability with 167 metabolites using Mendelian randomization with various sensitivity analyses and a reverse Mendelian randomization analysis. We extracted instruments for fasting glucose, 2-h glucose, fasting insulin, and glycated hemoglobin from the Meta-Analyses of Glucose and Insulin-related traits Consortium (n = 200,622), and those for type 2 diabetes liability from a meta-analysis of multiple cohorts (148,726 cases, 965,732 controls) in Europeans. Outcome data were from summary statistics of 167 metabolites from the UK Biobank (n = 115,078). Fasting glucose and 2-h glucose were not associated with any metabolite. Higher glycated hemoglobin was associated with higher free cholesterol in small low-density lipoprotein. Type 2 diabetes liability and fasting insulin were inversely associated with apolipoprotein A1, total cholines, lipoprotein subfractions in high-density-lipoprotein and intermediate-density lipoproteins, and positively associated with aromatic amino acids. These findings indicate hyperglycemia-independent patterns and highlight the role of insulin in type 2 diabetes development. Further studies should evaluate these glycemic traits in type 2 diabetes diagnosis and clinical management.

Causal association between lipoproteins and risk of coronary artery disease-a systematic review and meta-analysis of Mendelian randomization studies

OBJECTIVE

To systematically evaluate the causal effect of lipoproteins to the risk of coronary artery disease (CAD) by systematic review and meta-analysis of the associated Mendelian randomization (MR) studies.

METHODS

This systematic review was registered in PROSPERO (ID CRD42023465430). Searches from the databases (e.g., PubMed, Embase, Cochrane, Web of Science) and non-database sources to collect MR studies. The search time frame was from the database inception to August 2023. After data extraction, quality evaluation was performed, and the meta-analysis with bias evaluation was carried out with RevMan software.

RESULTS

A total of 5,828,409 participants from 21 records were included. Quality and bias assessment was performed by evaluating the internal three assumptions of MR studies. Meta-analysis for the causal association between non-HDL lipoproteins and CAD showed a significantly positive association between LDL and CAD (OR 1.37, 95% CI 1.26-1.49; P < 0.001, I2 = 95%), apoB and CAD (OR 1.38, 95% CI 1.11-1.71; P = 0.003, I2 = 98%), and Lp(a) and CAD (OR 1.21, 95% CI 1.12-1.31; P < 0.001, I2 = 99%). Interestingly, although there was no statistical significance in the association between VLDL/apoA1 and CAD (both P > 0.05), the pooled non-HDL lipoproteins showed a significantly positive association with CAD (OR 1.28, 95% CI 1.22-1.34; P < 0.001, I2 = 99%). For the HDL lipoproteins, the pooled OR showed a significantly negative association with CAD (OR 0.84, 95% CI 0.72-0.98; P = 0.002, I2 = 72%). However, the protective effect of HDL on CAD diminished when analyzed together with apoA1 and/or apoB (both P > 0.05). The funnel plot did not show serious publication bias, and sensitivity analysis performed relatively well robustness of the causal association of LDL, apoB, Lp(a), and total cholesterol with CAD.

CONCLUSION

The present meta-analysis suggests an overall effect of causal association between lipoproteins and CAD. Most of the non-HDL lipoproteins (LDL, apoB, Lp(a)) promote CAD, while the protective effect of HDL in CAD still needs to be verified in the future.

Local and systemic factors associated with quantitative stiffness of carotid plaque

PURPOSE

Plaque stiffness in carotid artery stenosis is a clinically important factor involved in the development of stroke and surgical complications. The purpose of this study was to clarify which local and systemic factors are associated with the quantitatively measured stiffness of plaque.

METHODS

The subjects were 104 consecutive patients who underwent carotid endarterectomy at our institution. To measure quantitative stiffness of plaque, we used an industrial hard meter in the operating room within 1 h after removal of plaque. Local factors related to carotid plaque hardness were evaluated, including maximum intima-media thickness (max IMT), degree of stenosis using the European Carotid Surgery Trial (ECST), presence of ulceration or calcification, and echo brightness on preoperative carotid ultrasound. The degree of stenosis was also evaluated using the North American Symptomatic Carotid Endarterectomy Trial method in digital subtraction angiography. Age, sex, and presence or absence of hypertension, diabetes, and dyslipidemia (low-density lipoprotein cholesterol and triglyceride [TG] levels) served as systemic factors and were compared with the quantitative stiffness of carotid plaque.

RESULTS

In multivariate analysis, ECST stenosis degree, calcification, and IMT max as local factors affected plaque stiffness. As a systemic factor, plaque stiffness was statistically significantly negatively correlated with TG values in multivariate analysis (p < 0.05).

CONCLUSION

The quantitative stiffness of the plaque was negatively correlated with TG levels as a systemic factor in addition to local factors. This might suggest that reducing high TG levels is associated with plaque stabilization.

Mendelian randomization studies on coronary artery disease: a systematic review and meta-analysis

BACKGROUND

Coronary artery disease (CAD) remains one of the leading causes of mortality worldwide. We aimed to summarize what is currently known with regard to causal modifiable risk factors associated with CAD in populations of diverse ancestries through conducting a systematic review and meta-analysis of Mendelian randomization (MR) studies on CAD.

METHODS

The databases Embase, Medline, Cochrane Library and Web of Science were searched on the 19th and 20th of December 2022 for MR studies with CAD as a primary outcome; keywords of the search strategy included "coronary artery disease" and "mendelian randomization". Studies were included if they were published in the English language, included only human participants, employed Mendelian randomization as the primary methodology and studied CAD as the outcome of interest. The exclusion criteria resulted in the removal of studies that did not align with the predefined inclusion criteria, as well as studies which were systematic reviews themselves, and used the same exposure and outcome source as another study. An ancestry-specific meta-analysis was subsequently conducted on studies which investigated either body mass index, lipid traits, blood pressure or type 2 diabetes as an exposure variable. Assessment of publication bias and sensitivity analyses was conducted for risk of bias assessment in the included studies.

RESULTS

A total of 1781 studies were identified through the database searches after de-duplication was performed, with 47 studies included in the quantitative synthesis after eligibility screening. Approximately 80% of all included study participants for MR studies on CAD were of European descent irrespective of the exposure of interest, while no study included individuals of African ancestry. We found no evidence of differences in terms of direction of causation between ancestry groups; however, the strength of the respective relationships between each exposure and CAD were different, with this finding most evident when blood pressure was the exposure of interest.

CONCLUSIONS

Findings from this review suggest that patterns regarding the causational relationship between modifiable risk factors and CAD do not differ in terms of direction when compared across diverse ancestry populations. Differences in the observed strengths of the respective relationships however are indicative of the value of increasing representation in non-European populations, as novel genetic pathways or functional SNPs relating to CAD may be uncovered through a more global analysis.

SYSTEMATIC REVIEW REGISTRATION

The protocol for this systematic review was registered to the International Prospective Register of Systematic Reviews (PROSPERO) and is publicly available online (CRD42021272726).

Type 2 Diabetes and HDL Dysfunction: A Key Contributor to Glycemic Control

High-density lipoproteins (HDL) have been shown to exert multiple cardioprotective and antidiabetic functions, such as their ability to promote cellular cholesterol efflux and their antioxidant, anti-inflammatory, and antiapoptotic properties. Type 2 diabetes (T2D) is usually associated with low high-density lipoprotein cholesterol (HDL-C) levels as well as with significant alterations in the HDL composition, thereby impairing its main functions. HDL dysfunction also negatively impacts both pancreatic β-cell function and skeletal muscle insulin sensitivity, perpetuating this adverse self-feeding cycle. The impairment of these pathways is partly dependent on cellular ATP-binding cassette transporter (ABC) A1-mediated efflux to lipid-poor apolipoprotein (apo) A-I in the extracellular space. In line with these findings, experimental interventions aimed at improving HDL functions, such as infusions of synthetic HDL or lipid-poor apoA-I, significantly improved glycemic control in T2D patients and experimental models of the disease. Cholesteryl ester transfer protein (CETP) inhibitors are specific drugs designed to increase HDLC and HDL functions. Posthoc analyses of large clinical trials with CETP inhibitors have demonstrated their potential anti-diabetic properties. Research on HDL functionality and HDL-based therapies could be a crucial step toward improved glycemic control in T2D subjects.

Antioxidant and Anti-Inflammatory Functions of High-Density Lipoprotein in Type 1 and Type 2 Diabetes

(1) Background: high-density lipoproteins (HDLs) exhibit antioxidant and anti-inflammatory properties that play an important role in preventing the development of atherosclerotic lesions and possibly also diabetes. In turn, both type 1 diabetes (T1D) and type 2 diabetes (T2D) are susceptible to having deleterious effects on these HDL functions. The objectives of the present review are to expound upon the antioxidant and anti-inflammatory functions of HDLs in both diabetes in the setting of atherosclerotic cardiovascular diseases and discuss the contributions of these HDL functions to the onset of diabetes. (2) Methods: this narrative review is based on the literature available from the PubMed database. (3) Results: several antioxidant functions of HDLs, such as paraoxonase-1 activity, are compromised in T2D, thereby facilitating the pro-atherogenic effects of oxidized low-density lipoproteins. In addition, HDLs exhibit diminished ability to inhibit pro-inflammatory pathways in the vessels of individuals with T2D. Although the literature is less extensive, recent evidence suggests defective antiatherogenic properties of HDL particles in T1D. Lastly, substantial evidence indicates that HDLs play a role in the onset of diabetes by modulating glucose metabolism. (4) Conclusions and perspectives: impaired HDL antioxidant and anti-inflammatory functions present intriguing targets for mitigating cardiovascular risk in individuals with diabetes. Further investigations are needed to clarify the influence of glycaemic control and nephropathy on HDL functionality in patients with T1D. Furthermore, exploring the effects on HDL functionality of novel antidiabetic drugs used in the management of T2D may provide intriguing insights for future research.

Identification of subgroups within a Japanese older adult population for whom statin therapy is effective in reducing mortality

Use of statins for primary prevention can reduce all-cause mortality in Asian elderly populations, but their effect and the specific effective subgroups in the elderly Japanese population remain unclear. This study examined the relationship between statin therapy for primary prevention and mortality reduction in older Japanese adults, and investigated the effective subgroups. The cohort study was conducted using the Shizuoka Kokuho Database (SKDB). Data were compared between the statin-treated group and a non-statin-treated (control) group using the inverse probability of treatment weighting (IPTW) method. In the SKDB cohort aged ≥65 years, new statin use was associated with a decreased risk of all-cause mortality (hazard ratio, 0.40; 95% confidence interval [CI], 0.33-0.48) after IPTW adjustment. The risk difference for mortality at 5 years in the statin-treated group compared with that in the control group was 0.05 (95% CI, 0.04-0.06), and the number needed to treat was 21.20 (95% CI, 18.10-24.70). In conclusion, statin use for primary prevention in older adults may reduce the risk of all-cause mortality in the population without atherosclerotic disease. Furthermore, statin use for primary prevention is feasible in patients aged 75 to <85 years and in patients with comorbidities such as diabetes, or dementia.

The evolving role of cholesteryl ester transfer protein inhibition beyond cardiovascular disease

The main role of cholesteryl ester transfer protein (CETP) is the transfer of cholesteryl esters and triglycerides between high-density lipoprotein (HDL) particles and triglyceride-rich lipoprotein and low-density lipoprotein (LDL) particles. There is a long history of investigations regarding the inhibition of CETP as a target for reducing major adverse cardiovascular events. Initially, the potential effect on cardiovascular events of CETP inhibitors was hypothesized to be mediated by their ability to increase HDL cholesterol, but, based on evidence from anacetrapib and the newest CETP inhibitor, obicetrapib, it is now understood to be primarily due to reducing LDL cholesterol and apolipoprotein B. Nevertheless, evidence is also mounting that other roles of HDL, including its promotion of cholesterol efflux, as well as its apolipoprotein composition and anti-inflammatory, anti-oxidative, and anti-diabetic properties, may play important roles in several diseases beyond cardiovascular disease, including, but not limited to, Alzheimer's disease, diabetes, and sepsis. Furthermore, although Mendelian randomization analyses suggested that higher HDL cholesterol is associated with increased risk of age-related macular degeneration (AMD), excess risk of AMD was absent in all CETP inhibitor randomized controlled trial data comprising over 70,000 patients. In fact, certain HDL subclasses may, in contrast, be beneficial for treating the retinal cholesterol accumulation that occurs with AMD. This review describes the latest biological evidence regarding the relationship between HDL and CETP inhibition for Alzheimer's disease, type 2 diabetes mellitus, sepsis, and AMD.

Appraising the Causal Role of Risk Factors in Coronary Artery Disease and Stroke: A Systematic Review of Mendelian Randomization Studies

BACKGROUND Mendelian randomization (MR) offers a powerful approach to study potential causal associations between exposures and health outcomes by using genetic variants associated with an exposure as instrumental variables. In this systematic review, we aimed to summarize previous MR studies and to evaluate the evidence for causality for a broad range of exposures in relation to coronary artery disease and stroke. METHODS AND RESULTS MR studies investigating the association of any genetically predicted exposure with coronary artery disease or stroke were identified. Studies were classified into 4 categories built on the significance of the main MR analysis results and its concordance with sensitivity analyses, namely, robust, probable, suggestive, and insufficient. Studies reporting associations that did not perform any sensitivity analysis were classified as nonevaluable. We identified 2725 associations eligible for evaluation, examining 535 distinct exposures. Of them, 141 were classified as robust, 353 as probable, 110 as suggestive, and 926 had insufficient evidence. The most robust associations were observed for anthropometric traits, lipids, and lipoproteins and type 2 diabetes with coronary artery; disease and clinical measurements with coronary artery disease and stroke; and thrombotic factors with stroke. CONCLUSIONS Despite the large number of studies that have been conducted, only a limited number of associations were supported by robust evidence. Approximately half of the studies reporting associations presented an MR sensitivity analysis along with the main analysis that further supported the causality of associations. Future research should focus on more thorough assessments of sensitivity MR analyses and further assessments of mediation effects or nonlinearity of associations.

Causality between depression and ankylosing spondylitis in a European population: Results from a Mendelian randomization analysis

The aim of this study was to explore the application of Mendelian randomization (MR) Egger and inverse variance weighted (IVW) in a causal effect on depression and ankylosing spondylitis (AS). Instrumental variables (IVs) were determined using genome-wide association studies. The 2-sample MR analysis was conducted by MR Egger to test the causal effect between depression and AS. The pleiotropy of potential instrumental variables was evaluated. The results of MR Egger and IVW were further compared. A total of 3 single nucleotide polymorphisms as the construct IVs were included. IVW results showed a significant causal effect between depression and AS (P < .001). Depression could promote the risk of AS (odds ratio = 1.060, 95% confidence interval: 1.026-1.094). However, the MR Egger showed no causal effect (P = .311). Heterogeneity statistics suggested that no heterogeneity was existed (P > .05). It was also suggested that there was no horizontal pleiotropy in IVs (MR Egger intercept: -0.0004, P = .471). Reverse MR analysis suggested that there was no causal effect between AS and depression (P > .05). Gene expression quantitative trait locus (QTLs) suggested that rs2517601 and RNF39 were positively correlated (beta = 1.066, P < .001). Depression may be one of the causes of AS by MR analysis in a European population. We can estimate the causal effect based on IVW when horizontal pleiotropy is very tiny.

Statins and risk of type 2 diabetes: mechanism and clinical implications

Statins are widely used to prevent cardiovascular disease events. Cardiovascular diseases and type 2 diabetes are tightly connected since type 2 diabetes is a major risk factor for cardiovascular diseases. Additionally, cardiovascular diseases often precede the development of type 2 diabetes. These two diseases have common genetic and environmental antecedents. Statins are effective in the lowering of cardiovascular disease events. However, they have also important side effects, including an increased risk of type 2 diabetes. The first study reporting an association of statin treatment with the risk of type 2 diabetes was the WOSCOPS trial (West of Scotland Coronary Prevention Study) in 2001. Other primary and secondary cardiovascular disease prevention studies as well as population-based studies have confirmed original findings. The purpose of our review is to examine and summarize the most important findings of these studies as well as to describe the mechanisms how statins increase the risk of type 2 diabetes.

Modulation of the Cellular microRNA Landscape: Contribution to the Protective Effects of High-Density Lipoproteins (HDL)

High-density lipoproteins (HDL) play an established role in protecting against cellular dysfunction in a variety of different disease contexts; however, harnessing this therapeutic potential has proved challenging due to the heterogeneous and relative instability of this lipoprotein and its variable cargo molecules. The purpose of this study is to examine the contribution of microRNA (miRNA; miR) sequences, either delivered directly or modulated endogenously, to these protective functions. This narrative review introduces the complex cargo carried by HDL, the protective functions associated with this lipoprotein, and the factors governing biogenesis, export and the uptake of microRNA. The possible mechanisms by which HDL can modulate the cellular miRNA landscape are considered, and the impact of key sequences modified by HDL is explored in diseases such as inflammation and immunity, wound healing, angiogenesis, dyslipidaemia, atherosclerosis and coronary heart disease, potentially offering new routes for therapeutic intervention.

Efficacy and safety of low levels of low-density lipoprotein cholesterol: trans-ancestry linear and non-linear Mendelian randomization analyses

AIMS

LDL cholesterol (LDL-C) is a well-established risk factor for coronary artery disease (CAD). However, the optimal LDL-C level with regard to efficacy and safety remains unclear. We aimed to investigate the causal relationships between LDL-C and efficacy and safety outcomes.

METHODS AND RESULTS

We analyzed 353 232 British from the UK Biobank and 41 271 Chinese from the China-PAR project. Linear and non-linear Mendelian randomization (MR) analyses were performed to evaluate the causal relation between genetically proxied LDL-C and CAD, all-cause mortality, and safety outcomes (including haemorrhagic stroke, diabetes mellitus, overall cancer, non-cardiovascular death, and dementia). No significant non-linear associations were observed for CAD, all-cause mortality, and safety outcomes (Cochran Q P > 0.25 in British and Chinese) with LDL-C levels above the minimum values of 50 and 20 mg/dL in British and Chinese, respectively. Linear MR analyses demonstrated a positive association of LDL-C with CAD [British: odds ratio (OR) per unit mmol/L increase, 1.75, P = 7.57 × 10-52; Chinese: OR, 2.06, P = 9.10 × 10-3]. Furthermore, stratified analyses restricted to individuals with LDL-C levels less than the guideline-recommended 70 mg/dL demonstrated lower LDL-C levels were associated with a higher risk of adverse events, including haemorrhagic stroke (British: OR, 0.72, P = 0.03) and dementia (British: OR, 0.75, P = 0.03).

CONCLUSION

In British and Chinese populations, we confirmed a linear dose-response relationship of LDL-C with CAD and found potential safety concerns at low LDL-C levels, providing recommendations for monitoring adverse events in people with low LDL-C in the prevention of cardiovascular disease.

U-shaped association between triglyceride and risk of incident diabetes in normoglycemic males with NAFLD: A population-base cohort study

Background: Serum triglyceride (TG) was an important biomarker for nonalcoholic fatty liver disease (NAFLD), and the association between TG and incident type 2 diabetes mellitus is still under debate with some studies suggesting that elevated TG increase the risk of incident T2DM while others indicative of a negative relationship. These controversial findings may be partially due to the inclusion of the participants with NAFLD. The association between TG and incident type 2 diabetes mellitus in people with NAFLD remained unclear. Therefore, this study aimed to characterize the relationship between the baseline TG levels and incident type 2 diabetes mellitus in a male Japanese cohort with NAFLD. Methods: A total of 1221 males with NAFLD were enrolled from the Nagala (NAFLD in the Gifu Area Longitudinal analysis) study conducted from 2004 to 2015. Cox proportional hazards models were performed to examine the relationship between baseline TG concentration and incident type 2 diabetes mellitus. A two-piecewise linear regression model was explored to evaluate the threshold effect of the baseline TG levels on type 2 diabetes mellitus incidence by using a smoothing function. Results: During a median follow-up of 6.05 years, 39 males with NAFLD at baseline developed type 2 diabetes mellitus. The risk of incident type 2 diabetes mellitus was significantly associated with baseline TG concentration in males with NAFLD after fully adjustment for confounders, with per 10 mg/dl elevation in TG levels increasing the risk of incident diabetes by 8.5% (HR=1.085, CI=1.039-1.132; P<0.001). However, no typical dose-dependent positive association between type 2 diabetes mellitus incidence and the TG levels was observed across the TG tertiles. Interestingly, a U-shaped association between TG concentration and risk of incident type 2 diabetes mellitus was revealed by the two-piecewise linear regression analysis. Baseline TG concentration lower than the threshold values (TG <53mg/dl) were negatively associated with risk of incident type 2 diabetes mellitus. With each 10mg/dl increase in baseline TG levels, the risk of incident type 2 diabetes mellitus decreased by nearly 59% (HR=0.413, 95% CI=0.220-0.778). In contrast, when TG levels were higher than the threshold values (TG>53mg/dl), the risk of incident diabetes increased 9.1% with every 10mg TG elevation (HR=1.091, 95% CI=1.046-1.137). Conclusions: A U-shaped relationship was observed between baseline TG levels and incident type 2 diabetes mellitus in a male normoglycemic Japanese population with NAFLD, although extrapolation of the finding to other populations should be made with caution.

Causal association between major depressive disorder and coronary heart disease: a two-sample bidirectional mendelian randomization study

BACKGROUND

Major depressive disorder (MDD) is a highly heterogeneous mental illness and a major public health problem worldwide. A large number of observational studies have demonstrated a clear association between MDD and coronary heart disease (CHD), and some studies have even suggested that the relationship is bidirectional. However, it was unknown whether any causal relationship existed between them and whether causality was bidirectional in such an instance. Thus, we aimed to determine whether there is a bidirectional causal relationship between major depressive disorders and coronary heart disease.

METHODS

Our two-sample Bidirectional Mendelian Randomization Study consisted of two parts: forward MR analysis regarded MDD as exposure and CHD as the outcome, and reverse MR analysis considered CHD as exposure and MDD as the outcome. Summary data on MDD and CHD were obtained from the IEU Open GWAS database. After screening criteria(P < [Formula: see text]), 47 MDD-associated SNPs and 39 CHD-associated SNPs were identified. The inverse-variance weighted (IVW) method, ME-Egger regression, and weighted median method were used to estimate causality. In addition, sensitivity methods, including the heterogeneity test, horizontal pleiotropy test, and leave-one-out method, were applied to ensure the robustness of causal estimation.

RESULTS

Based on the MR-Egger regression intercept test results, there did not appear to be any horizontal pleiotropy in this study (MDD: intercept = -0.0000376, P = 0.9996; CHD: intercept = -0.0002698, P = 0.920). Accordingly, IVW results suggested consistent estimates of causal effect values. The results showed that people with MDD increased the risk of CHD by 14.7% compared with those without MDD (OR = 1.147, 95%CI: 1.045-1.249, P = 0.009). But there was no direct evidence that CHD would increase the risk of MDD(OR = 1.008, 95%CI: 0.985-1.031, P = 0.490). The heterogeneity test and funnel plot showed no heterogeneity in 47 SNPs of MDD (Q = 42.28, [Formula: see text]=0, P = 0.629), but there was heterogeneity in 39 SNPs of CHD (Q = 62.48, [Formula: see text]=39.18%, P = 0.007). The leave-one-out method failed to identify instances where a single SNP was either biased toward or dependent on the causation.

CONCLUSION

Our study supports a one-way causal relationship between MDD and CHD, but there is no bidirectional causal relationship. MDD increases the risk of CHD, but there is no evidence that CHD increases the risk of MDD. Therefore, the influence of psychological factors should also be considered in the prevention and treatment of CHD. For MDD patients, it is necessary to prevent cardiovascular diseases.

Targeting PCSK9 and Beyond for the Management of Low-Density Lipoprotein Cholesterol

Reducing low-density lipoprotein cholesterol (LDL-C) levels is crucial to the prevention of atherosclerotic cardiovascular disease (ASCVD). However, many patients, especially those at very high ASCVD risk or with familial hypercholesterolemia (FH), do not achieve target LDL-C levels with statin monotherapy. The underutilization of novel lipid-lowering therapies (LLT) globally may be due to cost concerns or therapeutic inertia. Emerging approaches have the potential to lower LDL-C and reduce ASCVD risk further, in addition to offering alternatives for statin-intolerant patients. Shifting the treatment paradigm towards initial combination therapy and utilizing novel LLT strategies can complement existing treatments. This review discusses innovative approaches including combination therapies involving statins and agents like ezetimibe, bempedoic acid, cholesterol ester transfer protein (CETP) inhibitors as well as strategies targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) and angiopoietin-like protein 3 (ANGPTL3) inhibition. Advances in nucleic acid-based therapies and gene editing are innovative approaches that will improve patient compliance and adherence. These strategies demonstrate significant LDL-C reductions and improved cardiovascular outcomes, offering potential for optimal LDL-C control and reduced ASCVD risk. By addressing the limitations of statin monotherapy, these approaches provide new management options for elevated LDL-C levels.

Can HDL cholesterol be replaced by paraoxonase 1 activity in the prediction of severe coronary artery disease in patients with type 2 diabetes?

BACKGROUND AND AIMS

Novel biomarkers are required to improve cardiovascular disease prediction in patients with type 2 diabetes (T2D) as a high-risk population. This study was conducted to examine whether coronary artery disease (CAD) risk assessment can be improved by substituting high-density lipoprotein (HDL)-bound paraoxonase 1 (PON1) activity for HDL cholesterol (HDL-C) concentration in patients with T2D.

METHODS AND RESULTS

In this study, we studied 139 patients with T2D (mean age 64.12 ± 8.17 years) who underwent coronary angiographic examination. The initial rate of substrate hydrolysis was spectrophotometrically assayed in kinetic mode for measuring PON1 activity. Receiver operating characteristic (ROC) graphs are created by plotting true positivity versus false positivity. In patients with HbA_1c ≥ 7%, PON1 (AUC = 0.7, p = 0.029) and nonHDL-C/PON1 (AUC = 0.75, p = 0.013) were significantly more capable of differentiating patients with CAD from those without CAD compared to HDL-C and nonHDL-C/HDL-C. Also, the predictive power of PON1 (AUC = 0.64, p = 0.029) and nonHDL-C/PON1 (AUC = 0.71, p = 0.004) were significantly higher in comparison with HDL-C and nonHDL-C/HDL-C for CAD characterization in patients aged ≥50 years. Moreover, PON1 and nonHDL-C/PON1 are associated with the incidence of CAD with an AUC of 0.7 (p = 0.026) and AUC of 0.64 (p = 0.087), respectively, among subjects with low HDL-C.

CONCLUSION

PON1 and the ratio of nonHDL-C/PON1 significantly improve the prediction of severe CAD in T2D patients and in patients with HbA_1c ≥ 7%, age ≥50 years, or low HDL-C. PON1 activity and lipid ratios using this enzyme may be valuable as substitutes of HDL-C for increasing clinical efficacies in cardiovascular risk assessment.

Differences in HDL-related mortality risk between individuals with and without hypertension: a prospective cohort study in UK Biobank

BACKGROUND AND AIMS

Very high levels of high-density lipoprotein cholesterol (HDL-C) have been paradoxically linked to increased mortality risk. The present study aimed to examine associations of HDL-C and varied sizes of the HDL particle (HDL-P) with mortality risk stratified by hypertension.

METHODS AND RESULTS

This prospective cohort study included 429 792 participants (244 866 with hypertension and 184 926 without hypertension) from the UK Biobank. During a median follow-up of 12.7 years, 23 993 (9.8%) and 8142 (4.4%) deaths occurred among individuals with and without hypertension, respectively. A U-shaped association of HDL-C with all-cause mortality was observed in individuals with hypertension after multivariable adjustment, whereas an L-shape was observed in individuals without hypertension. Compared with individuals with normal HDL-C of 50-70 mg/dL, those with very high HDL-C levels (>90 mg/dL) had a significantly higher risk of all-cause mortality among individuals with hypertension (hazard ratio, 1.47; 95% confidence interval, 1.35-1.61), but not among those without hypertension (1.05, 0.91-1.22). As for HDL-P, among individuals with hypertension, a larger size of HDL-P was positively whereas smaller HDL-P was negatively associated with all-cause mortality. After additional adjustment for larger HDL-P in the model, the U-shaped association between HDL-C and mortality risk was altered to an L-shape among individuals with hypertension.

CONCLUSIONS

The increased risk of mortality associated with very high HDL-C existed only in individuals with hypertension, but not in those without hypertension. Moreover, the increased risk at high HDL-C levels in hypertension was likely driven by larger HDL-P.

Unraveling the metabolic underpinnings of frailty using multicohort observational and Mendelian randomization analyses

Identifying metabolic biomarkers of frailty, an age-related state of physiological decline, is important for understanding its metabolic underpinnings and developing preventive strategies. Here, we systematically examined 168 nuclear magnetic resonance-based metabolomic biomarkers and 32 clinical biomarkers for their associations with frailty. In up to 90,573 UK Biobank participants, we identified 59 biomarkers robustly and independently associated with the frailty index (FI). Of these, 34 associations were replicated in the Swedish TwinGene study (n = 11,025) and the Finnish Health 2000 Survey (n = 6073). Using two-sample Mendelian randomization, we showed that the genetically predicted level of glycoprotein acetyls, an inflammatory marker, was statistically significantly associated with an increased FI (β per SD increase = 0.37%, 95% confidence interval: 0.12-0.61). Creatinine and several lipoprotein lipids were also associated with increased FI, yet their effects were mostly driven by kidney and cardiometabolic diseases, respectively. Our findings provide new insights into the causal effects of metabolites on frailty and highlight the role of chronic inflammation underlying frailty development.

Genetically mimicked effects of ASGR1 inhibitors on all-cause mortality and health outcomes: a drug-target Mendelian randomization study and a phenome-wide association study

BACKGROUND

Asialoglycoprotein receptor 1 (ASGR1) is emerging as a potential drug target to reduce low-density lipoprotein (LDL)-cholesterol and coronary artery disease (CAD) risk. Here, we investigated genetically mimicked ASGR1 inhibitors on all-cause mortality and any possible adverse effects.

METHODS

We conducted a drug-target Mendelian randomization study to assess genetically mimicked effects of ASGR1 inhibitors on all-cause mortality and 25 a priori outcomes relevant to lipid traits, CAD, and possible adverse effects, i.e. liver function, cholelithiasis, adiposity and type 2 diabetes. We also performed a phenome-wide association study of 1951 health-related phenotypes to identify any novel effects. Associations found were compared with those for currently used lipid modifiers, assessed using colocalization, and replicated where possible.

RESULTS

Genetically mimicked ASGR1 inhibitors were associated with a longer lifespan (3.31 years per standard deviation reduction in LDL-cholesterol, 95% confidence interval 1.01 to 5.62). Genetically mimicked ASGR1 inhibitors were inversely associated with apolipoprotein B (apoB), triglycerides (TG) and CAD risk. Genetically mimicked ASGR1 inhibitors were positively associated with alkaline phosphatase, gamma glutamyltransferase, erythrocyte traits, insulin-like growth factor 1 (IGF-1) and C-reactive protein (CRP), but were inversely associated with albumin and calcium. Genetically mimicked ASGR1 inhibitors were not associated with cholelithiasis, adiposity or type 2 diabetes. Associations with apoB and TG were stronger for ASGR1 inhibitors compared with currently used lipid modifiers, and most non-lipid effects were specific to ASGR1 inhibitors. The probabilities for colocalization were > 0.80 for most of these associations, but were 0.42 for lifespan and 0.30 for CAD. These associations were replicated using alternative genetic instruments and other publicly available genetic summary statistics.

CONCLUSIONS

Genetically mimicked ASGR1 inhibitors reduced all-cause mortality. Beyond lipid-lowering, genetically mimicked ASGR1 inhibitors increased liver enzymes, erythrocyte traits, IGF-1 and CRP, but decreased albumin and calcium.

Adiposity and lipid metabolism indicators mediate the adverse effect of glucose metabolism indicators on oogenesis and embryogenesis in PCOS women undergoing IVF/ICSI cycles

BACKGROUND

Polycystic ovary syndrome (PCOS) women have high incidences of dyslipidemia, obesity, impaired glucose tolerance (IGT), diabetes, and insulin resistance (IR) and are fragile to female infertility. Obesity and dyslipidemia may be the intermediate biological mechanism for the associations between glucose metabolism dysfunction and abnormal oogenesis and embryogenesis.

METHODS

This retrospective cohort study was performed at a university-affiliated reproductive center. A total of 917 PCOS women aged between 20 and 45 undergoing their first IVF/ICSI embryo transfer cycles from January 2018 to December 2020 were involved. Associations between glucose metabolism indicators, adiposity and lipid metabolism indicators, and IVF/ICSI outcomes were explored using multivariable generalized linear models. Mediation analyses were further performed to examine the potential mediation role of adiposity and lipid metabolism indicators.

RESULTS

Significant dose-dependent relationships were found between glucose metabolism indicators and IVF/ICSI early reproductive outcomes and between glucose metabolism indicators and adiposity and lipid metabolism indicators (all P < 0.05). Also, we found significant dose-dependent relationships between adiposity and lipid metabolism indicators and IVF/ICSI early reproductive outcomes (all P < 0.05). The mediation analysis indicated that elevated FPG, 2hPG, FPI, 2hPI, HbA1c, and HOMA2-IR were significantly associated with decreased retrieved oocyte count, MII oocyte count, normally fertilized zygote count, normally cleaved embryo count, high-quality embryo count, or blastocyst formation count after controlling for adiposity and lipid metabolism indicators. Serum TG mediated 6.0-31.0% of the associations; serum TC mediated 6.1-10.8% of the associations; serum HDL-C mediated 9.4-43.6% of the associations; serum LDL-C mediated 4.2-18.2% of the associations; and BMI mediated 26.7-97.7% of the associations.

CONCLUSIONS

Adiposity and lipid metabolism indicators (i.e., serum TG, serum TC, serum HDL-C, serum LDL-C, and BMI) are significant mediators of the effect of glucose metabolism indicators on IVF/ICSI early reproductive outcomes in PCOS women, indicating the importance of preconception glucose and lipid management and the dynamic equilibrium of glucose and lipid metabolism in PCOS women.

Genetic polymorphism of the Dab2 gene and its association with Type 2 Diabetes Mellitus in the Chinese Uyghur population

Objective

The human Disabled-2 (Dab2) protein is an endocytic adaptor protein, which plays an essential role in endocytosis of transmembrane cargo, including low-density lipoprotein cholesterol (LDL-C). As a candidate gene for dyslipidemia, Dab2 is also involved in the development of type 2 diabetes mellitus(T2DM). The aim of this study was to investigate the effects of genetic variants of the Dab2 gene on the related risk of T2DM in the Uygur and Han populations of Xinjiang, China.

Methods

A total of 2,157 age- and sex-matched individuals (528 T2DM patients and 1,629 controls) were included in this case-control study. Four high frequency SNPs (rs1050903, rs2255280, rs2855512 and rs11959928) of the Dab2 gene were genotyped using an improved multiplex ligation detection reaction (iMLDR) genotyping assay, and the forecast value of the SNP for T2DM was assessed by statistical analysis of clinical data profiles and gene frequencies.

Results

We found that in the Uygur population studied, for both rs2255280 and rs2855512, there were significant differences in the distribution of genotypes (AA/CA/CC), and the recessive model (CC vs. CA + AA) between T2DM patients and the controls (P < 0.05). After adjusting for confounders, the recessive model (CC vs. CA + AA) of both rs2255280 and rs2855512 remained significantly associated with T2DM in this population (rs2255280: OR = 5.303, 95% CI [1.236 to -22.755], P = 0.025; rs2855512: OR = 4.892, 95% CI [1.136 to -21.013], P = 0.033). The genotypes (AA/CA/CC) and recessive models (CC vs. CA + AA) of rs2855512 and rs2255280 were also associated with the plasma glucose and HbA1c levels (all P < 0.05) in this population. There were no significant differences in genotypes, all genetic models, or allele frequencies between the T2DM and control group in the Han population group (all P > 0.05).

Conclusions

The present study suggests that the variation of the Dab2 gene loci rs2255280 and rs2855512 is related to the incidence of T2DM in the Uygur population, but not in the Han population. In this study, these variations in Dab2 were an independent predictor for T2DM in the Uygur population of Xinjiang, China.

Evaluating the distinct pleiotropic effects of omega-3 fatty acids on type 2 diabetes mellitus: a mendelian randomization study

BACKGROUND

Observational studies and conventional Mendelian randomization (MR) studies showed inconclusive evidence to support the association between omega-3 fatty acids and type 2 diabetes. We aim to evaluate the causal effect of omega-3 fatty acids on type 2 diabetes mellitus (T2DM), and the distinct intermediate phenotypes linking the two.

METHODS

Two-sample MR was performed using genetic instruments derived from a recent genome-wide association study (GWAS) of omega-3 fatty acids (N = 114,999) from UK Biobank and outcome data obtained from a large-scale T2DM GWAS (62,892 cases and 596,424 controls) in European ancestry. MR-Clust was applied to determine clustered genetic instruments of omega-3 fatty acids that influences T2DM. Two-step MR analysis was used to identify potential intermediate phenotypes (e.g. glycemic traits) that linking omega-3 fatty acids with T2DM.

RESULTS

Univariate MR showed heterogenous effect of omega-3 fatty acids on T2DM. At least two pleiotropic effects between omega-3 fatty acids and T2DM were identified using MR-Clust. For cluster 1 with seven instruments, increasing omega-3 fatty acids reduced T2DM risk (OR: 0.52, 95%CI 0.45-0.59), and decreased HOMA-IR (β = - 0.13, SE = 0.05, P = 0.02). On the contrary, MR analysis using 10 instruments in cluster 2 showed that increasing omega-3 fatty acids increased T2DM risk (OR:1.10; 95%CI 1.06-1.15), and decreased HOMA-B (β = - 0.04, SE = 0.01, P = 4.52 × 10^-5). Two-step MR indicated that increasing omega-3 fatty acid levels decreased T2DM risk via decreasing HOMA-IR in cluster 1, while increased T2DM risk via decreasing HOMA-B in cluster 2.

CONCLUSIONS

This study provides evidence to support two distinct pleiotropic effects of omega-3 fatty acids on T2DM risk influenced by different gene clusters, which could be partially explained by distinct effects of omega-3 fatty acids on insulin resistance and beta cell dysfunction. The pleiotropic feature of omega-3 fatty acids variants and its complex relationships with T2DM need to be carefully considered in future genetic and clinical studies.

Uncovering genetic associations in the human diseasome using an endophenotype-augmented disease network

Many diseases exhibit complex multimorbidities with one another. An intuitive way to model the connections between phenotypes is with a disease-disease network (DDN), where nodes represent diseases and edges represent associations, such as shared single-nucleotide polymorphisms (SNPs), between pairs of diseases. To gain further genetic understanding of molecular contributors to disease associations, we propose a novel version of the shared-SNP DDN (ssDDN), denoted as ssDDN+, which includes connections between diseases derived from genetic correlations with endophenotypes. We hypothesize that a ssDDN+ can provide complementary information to the disease connections in a ssDDN, yielding insight into the role of clinical laboratory measurements in disease interactions. Using PheWAS summary statistics from the UK Biobank, we constructed a ssDDN+ revealing hundreds of genetic correlations between disease phenotypes and quantitative traits. Our augmented network uncovers genetic associations across different disease categories, connects relevant cardiometabolic diseases, and highlights specific biomarkers that are associated with cross-phenotype associations. Out of the 31 clinical measurements under consideration, HDL-C connects the greatest number of diseases and is strongly associated with both type 2 diabetes and diabetic retinopathy. Triglycerides, another blood lipid with known genetics causes in non-mendelian diseases, also adds a substantial number of edges to the ssDDN. Our study can facilitate future network-based investigations of cross-phenotype associations involving pleiotropy and genetic heterogeneity, potentially uncovering sources of missing heritability in multimorbidities.

Distinct metabolic features of genetic liability to type 2 diabetes and coronary artery disease: a reverse Mendelian randomization study

BACKGROUND

Type 2 diabetes (T2D) and coronary artery disease (CAD) both have known genetic determinants, but the mechanisms through which their associated genetic variants lead to disease onset remain poorly understood.

METHODS

We used large-scale metabolomics data in a two-sample reverse Mendelian randomization (MR) framework to estimate effects of genetic liability to T2D and CAD on 249 circulating metabolites in the UK Biobank (N = 118,466). We examined the potential for medication use to distort effect estimates by conducting age-stratified metabolite analyses.

FINDINGS

Using inverse variance weighted (IVW) models, higher genetic liability to T2D was estimated to decrease high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) (e.g.

, HDL-C

 -0.05 SD; 95% CI -0.07 to -0.03, per doubling of liability), whilst increasing all triglyceride groups and branched chain amino acids (BCAAs). IVW estimates for CAD liability suggested an effect on reducing HDL-C as well as raising very-low density lipoprotein cholesterol (VLDL-C) and LDL-C. In pleiotropy-robust models, T2D liability was still estimated to increase BCAAs, but several estimates for higher CAD liability reversed and supported decreased LDL-C and apolipoprotein-B. Estimated effects of CAD liability differed substantially by age for non-HDL-C traits, with higher CAD liability lowering LDL-C only at older ages when statin use was common.

INTERPRETATION

Overall, our results support largely distinct metabolic features of genetic liability to T2D and CAD, illustrating both challenges and opportunities for preventing these commonly co-occurring diseases.

FUNDING

Wellcome Trust [218495/Z/19/Z], UK MRC [MC_UU_00011/1; MC_UU_00011/4], the University of Bristol, Diabetes UK [17/0005587], World Cancer Research Fund [IIG_2019_2009].

Correlation of elevated serum uric acid with coronary artery disease in Xinjiang, China: A retrospective case-control study

Elevated serum uric acid (SUA) levels are associated with coronary artery disease (CAD). However, whether this association is independent of traditional cardiovascular risk factors remains controversial. Our study aimed to determine the concentration of SUA in the presence and severity of CAD in multi-ethnic patients in Xinjiang, China. For this study, 412 consecutive patients with percutaneous coronary intervention (PCI) and 845 individuals with normal coronary angiograms were included in the study. CAD severity was evaluated using the Gensini score index. The SUA concentrations and the levels of various cardiometabolic risk factors were investigated. We assessed the relationship between SUA levels and other cardiometabolic risk factors. Logistic regression was used to evaluate risk factors for PCI patients. SUA levels were significantly elevated in PCI patients compared to those in control subjects (P < .01). With increased UA levels, we found that the risk factors for CAD increased. SUA concentration had a significant positive relationship with total cholesterol (P < .01), triglycerides (P < .01), low-density lipoprotein cholesterol (P < .01), and creatinine (P < .01) in both sexes. In the PCI group, there was no significant correlation between UA levels. SUA levels are not an independent risk factor for CAD. It can be concluded that in Xinjiang, China, SUA is related to multiple risk factors for CAD, but not related to the severity of CAD.

Phenome-wide Mendelian randomization study of plasma triglyceride levels and 2600 disease traits

Background

Causality between plasma triglyceride (TG) levels and atherosclerotic cardiovascular disease (ASCVD) risk remains controversial despite more than four decades of study and two recent landmark trials, STRENGTH, and REDUCE-IT. Further unclear is the association between TG levels and non-atherosclerotic diseases across organ systems.

Methods

Here, we conducted a phenome-wide, two-sample Mendelian randomization (MR) analysis using inverse-variance weighted (IVW) regression to systematically infer the causal effects of plasma TG levels on 2600 disease traits in the European ancestry population of UK Biobank. For replication, we externally tested 221 nominally significant associations (p<0.05) in an independent cohort from FinnGen. To account for potential horizontal pleiotropy and the influence of invalid instrumental variables, we performed sensitivity analyses using MR-Egger regression, weighted median estimator, and MR-PRESSO. Finally, we used multivariable MR (MVMR) controlling for correlated lipid fractions to distinguish the independent effect of plasma TG levels.

Results

Our results identified seven disease traits reaching Bonferroni-corrected significance in both the discovery (p<1.92 × 10-5) and replication analyses (p<2.26 × 10-4), suggesting a causal relationship between plasma TG levels and ASCVDs, including coronary artery disease (OR 1.33, 95% CI 1.24-1.43, p=2.47 × 10-13). We also identified 12 disease traits that were Bonferroni-significant in the discovery or replication analysis and at least nominally significant in the other analysis (p<0.05), identifying plasma TG levels as a novel potential risk factor for nine non-ASCVD diseases, including uterine leiomyoma (OR 1.19, 95% CI 1.10-1.29, p=1.17 × 10-5).

Conclusions

Taking a phenome-wide, two-sample MR approach, we identified causal associations between plasma TG levels and 19 disease traits across organ systems. Our findings suggest unrealized drug repurposing opportunities or adverse effects related to approved and emerging TG-lowering agents, as well as mechanistic insights for future studies.

Funding

RD is supported by the National Institute of General Medical Sciences of the National Institutes of Health (NIH) (R35-GM124836) and the National Heart, Lung, and Blood Institute of the NIH (R01-HL139865 and R01-HL155915).

The relationship between high density lipoprotein cholesterol and sepsis: A clinical and genetic approach

Sepsis accounts for one in three hospital deaths. Higher concentrations of high-density lipoprotein cholesterol (HDL-C) are associated with apparent protection from sepsis, suggesting a potential therapeutic role for HDL-C or drugs, such as cholesteryl ester transport protein (CETP) inhibitors that increase HDL-C. However, these beneficial clinical associations might be due to confounding; genetic approaches can address this possibility. We identified 73,406 White adults admitted to Vanderbilt University Medical Center with infection; 11,612 had HDL-C levels, and 12,377 had genotype information from which we constructed polygenic risk scores (PRS) for HDL-C and the effect of CETP on HDL-C. We tested the associations between predictors (measured HDL-C, HDL-C PRS, CETP PRS, and rs1800777) and outcomes: sepsis, septic shock, respiratory failure, and in-hospital death. In unadjusted analyses, lower measured HDL-C concentrations were significantly associated with increased risk of sepsis (p = 2.4 × 10-23 ), septic shock (p = 4.1 × 10-12 ), respiratory failure (p = 2.8 × 10-8 ), and in-hospital death (p = 1.0 × 10-8 ). After adjustment (age, sex, electronic health record length, comorbidity score, LDL-C, triglycerides, and body mass index), these associations were markedly attenuated: sepsis (p = 2.6 × 10-3 ), septic shock (p = 8.1 × 10-3 ), respiratory failure (p = 0.11), and in-hospital death (p = 4.5 × 10-3 ). HDL-C PRS, CETP PRS, and rs1800777 significantly predicted HDL-C (p < 2 × 10-16 ), but none were associated with sepsis outcomes. Concordant findings were observed in 13,254 Black patients hospitalized with infections. Lower measured HDL-C levels were significantly associated with increased risk of sepsis and related outcomes in patients with infection, but a causal relationship is unlikely because no association was found between the HDL-C PRS or the CETP PRS and the risk of adverse sepsis outcomes.

High-Density Lipoprotein Alterations in Type 2 Diabetes and Obesity

Alterations affecting high-density lipoproteins (HDLs) are one of the various abnormalities observed in dyslipidemia in type 2 diabetes mellitus (T2DM) and obesity. Kinetic studies have demonstrated that the catabolism of HDL particles is accelerated. Both the size and the lipidome and proteome of HDL particles are significantly modified, which likely contributes to some of the functional defects of HDLs. Studies on cholesterol efflux capacity have yielded heterogeneous results, ranging from a defect to an improvement. Several studies indicate that HDLs are less able to inhibit the nuclear factor kappa-B (NF-κB) proinflammatory pathway, and subsequently, the adhesion of monocytes on endothelium and their recruitment into the subendothelial space. In addition, the antioxidative function of HDL particles is diminished, thus facilitating the deleterious effects of oxidized low-density lipoproteins on vasculature. Lastly, the HDL-induced activation of endothelial nitric oxide synthase is less effective in T2DM and metabolic syndrome, contributing to several HDL functional defects, such as an impaired capacity to promote vasodilatation and endothelium repair, and difficulty counteracting the production of reactive oxygen species and inflammation.

Virgin Coconut Oil: A Dietary Intervention for Dyslipidaemia in Patients with Diabetes Mellitus

Hyperlipidaemia is causally related to coronary artery diseases (CAD) and peripheral artery diseases (PAD) in people with Diabetes Mellitus (DM). An in vivo study confirmed that virgin coconut oil (VCO) could maintain levels of lipids in the blood as effectively as conventional therapy. Therefore, this study aimed to determine the effect of VCO on the lipid profiles and ankle-brachial index (ABI) of patients with DM. In this experimental study with pre- and post-test design and a control group, the participants were selected purposively. The ABI was evaluated on the first visit. Baseline lipid profile readings were taken. Each participant took 1.2 mL/kgBW of VCO daily and divided it into three doses. After 30 days of taking VCO, laboratory examinations and ABI were repeated, and adverse events were evaluated. The dependent t-test and Wilcoxon sign rank test with a significance level of α ≤ 0.05 showed a significant decrease in low-density lipoprotein (LDL) (p = 0.002), a significant increase in high-density lipoprotein (HDL) levels (p = 0.031), a significant decrease in energy intake (p = 0.046) and cholesterol intake (p = 0.023) at the endpoint in the VCO group. In conclusion, this therapy is beneficial for maintaining lipid profile when combined with dietary therapy. Future studies should investigate the duration and dosage of VCO on patients to maintain lipid-linked protein.

Investigating sex-specific associations of lipid traits with type 2 diabetes, glycemic traits and sex hormones using Mendelian randomization

BACKGROUND

Low-density lipoprotein (LDL)-cholesterol is positively associated with cardiovascular disease (CVD) and inversely associated with type 2 diabetes, which could detract from lipid modification. Here, we examined whether lipid traits potentially relevant to CVD aetiology, i.e. apolipoprotein B (apoB), triglycerides (TG) and lipoprotein(a) [Lp(a)] exhibited the same associations. We investigated sex-specifically, including the role of sex hormones, because sex disparities exist in lipid profile and type 2 diabetes. We also replicated where possible.

METHODS

We used Mendelian randomization (MR) to examine sex-specific associations of apoB, TG and Lp(a) with type 2 diabetes, HbA1c, fasting insulin, fasting glucose, testosterone and estradiol in the largest relevant sex-specific genome-wide association studies (GWAS) in people of European ancestry and replicated where possible. We also assessed sex-specific associations of liability to type 2 diabetes with apoB, TG and Lp(a).

RESULTS

Genetically predicted apoB and Lp(a) had little association with type 2 diabetes or glycemic traits in women or men. Genetically predicted higher TG was associated with higher type 2 diabetes risk [odds ratio (OR) 1.44 per standard deviation (SD), 95% confidence interval (CI) 1.26 to 1.65], HbA1c and fasting insulin specifically in women. Higher TG was associated with lower testosterone in women and higher testosterone in men, but with lower estradiol in men and women. Genetic liability to type 2 diabetes was associated with higher TG in women, and possibly with lower apoB in men.

CONCLUSIONS

Lipid traits potentially relevant to CVD aetiology do not exhibit contrasting associations with CVD and type 2 diabetes. However, higher TG is associated with higher type 2 diabetes risk and glycemic traits, which in turn further increases TG specifically in women, possibly driven by sex hormones.

Prevalence of Diabetes and Its Association with Atherosclerotic Cardiovascular Disease Risk in Patients with Familial Hypercholesterolemia: An Analysis from the Hellenic Familial Hypercholesterolemia Registry (HELLAS-FH)

Familial hypercholesterolemia (FH) and type 2 diabetes mellitus (T2DM) are both associated with a high risk of atherosclerotic cardiovascular disease (ASCVD). Little is known about the prevalence of T2DM and its association with ASCVD risk in FH patients. This was a cross-sectional analysis from the Hellenic Familial Hypercholesterolemia Registry (HELLAS-FH) including adults with FH (n = 1719, mean age 51.3 ± 14.6 years). Of FH patients, 7.2% had a diagnosis of T2DM. The prevalence of ASCVD, coronary artery disease (CAD), and stroke was higher among subjects with T2DM compared with those without (55.3% vs. 23.3%, 48.8% vs. 20.7%, 8.3% vs. 2.7%, respectively, p < 0.001). When adjusted for age, systolic blood pressure, smoking, body mass index, hypertension, waist circumference, triglyceride levels, high-density lipoprotein cholesterol levels, and gender, T2DM was significantly associated with prevalent ASCVD [OR 2.0 (95% CI 1.2−3.3), p = 0.004]. FH patients with T2DM were more likely to have undergone coronary revascularization than those without (14.2% vs. 4.5% for coronary artery bypass graft, and 23.9% vs. 11.5% for percutaneous coronary intervention, p < 0.001). T2DM is associated with an increased risk for prevalent ASCVD in subjects with FH. This may have implications for risk stratification and treatment intensity in these patients.

Causal Association of Obesity and Dyslipidemia with Type 2 Diabetes: A Two-Sample Mendelian Randomization Study

Recent studies have suggested an association between obesity and dyslipidemia in the development of type 2 diabetes (T2D). The purpose of this study was to explore the causal effects of obesity and dyslipidemia on T2D risk in Asians. Two-sample Mendelian randomization (MR) analyses were performed to assess genetically predicted obesity using body mass index (BMI) and dyslipidemia using high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), total cholesterol (TCHL), and triglycerides (TG) versus T2D susceptibility using genome-wide association study (GWAS) results derived from the summary statistics of Biobank Japan (n = 179,000) and DIAbetes Meta-ANalysis of Trans-Ethnic association studies (n = 50,533). The MR analysis demonstrated evidence of a causal effect of higher BMI on the risk of T2D (odds ratio (OR) > 1.0, p < 0.05). In addition, TG showed a protective effect on the risk of T2D (ORs 0.68-0.85). However, HDL, LDL, and TCHL showed little genetic evidence supporting a causal association between dyslipidemia and T2D. We found strong genetic evidence supporting a causal association of BMI with T2D. Although HDL, LDL, and TCHL did not show a causal association with T2D, TG had a causal relationship with the decrease of T2D. Although it was predicted that TG would be linked to a higher risk of T2D, it actually exhibited a paradoxical protective effect against T2D, which requires further investigation.

High-density lipoprotein revisited: biological functions and clinical relevance

Previous interest in high-density lipoproteins (HDLs) focused on their possible protective role in atherosclerotic cardiovascular disease (ASCVD). Evidence from genetic studies and randomized trials, however, questioned that the inverse association of HDL-cholesterol (HDL-C) is causal. This review aims to provide an update on the role of HDL in health and disease, also beyond ASCVD. Through evolution from invertebrates, HDLs are the principal lipoproteins, while apolipoprotein B-containing lipoproteins first developed in vertebrates. HDLs transport cholesterol and other lipids between different cells like a reusable ferry, but serve many other functions including communication with cells and the inactivation of biohazards like bacterial lipopolysaccharides. These functions are exerted by entire HDL particles or distinct proteins or lipids carried by HDL rather than by its cholesterol cargo measured as HDL-C. Neither does HDL-C measurement reflect the efficiency of reverse cholesterol transport. Recent studies indicate that functional measures of HDL, notably cholesterol efflux capacity, numbers of HDL particles, or distinct HDL proteins are better predictors of ASCVD events than HDL-C. Low HDL-C levels are related observationally, but also genetically, to increased risks of infectious diseases, death during sepsis, diabetes mellitus, and chronic kidney disease. Additional, but only observational, data indicate associations of low HDL-C with various autoimmune diseases, and cancers, as well as all-cause mortality. Conversely, extremely high HDL-C levels are associated with an increased risk of age-related macular degeneration (also genetically), infectious disease, and all-cause mortality. HDL encompasses dynamic multimolecular and multifunctional lipoproteins that likely emerged during evolution to serve several physiological roles and prevent or heal pathologies beyond ASCVD. For any clinical exploitation of HDL, the indirect marker HDL-C must be replaced by direct biomarkers reflecting the causal role of HDL in the respective disease.