Cardiovascular diseases are the leading cause of death worldwide, with atherosclerosis as most common underlying pathology. Atherosclerosis is characterized by arterial narrowing due to cholesterol... Show moreCardiovascular diseases are the leading cause of death worldwide, with atherosclerosis as most common underlying pathology. Atherosclerosis is characterized by arterial narrowing due to cholesterol and lipid accumulation. Despite available effective cholesterol lowering medication, considerable risk for recurrent vascular events remains. This residual risk is at least in part explained by high blood lipid levels. The research described in this thesis revealed novel therapeutic strategies that improve lipid metabolism and reduce atherosclerosis development in mice. Inhibition of the endocannabinoid system was found to be an effective strategy, as well as concomitant activation of two incretin hormone receptors, namely those for GIP and GLP1. For combined GIP/GLP1 receptor agonism we additionally showed strongly attenuated hepatic steatosis. We were also able to identify additional targets to attenuate hyperlipidemia by studying the mechanisms underlying the strong day-night rhythm of brown adipose tissue, which is a lipid combusting tissue. In this thesis, I also stress the importance of the choice in animal model when studying lipid-modifying interventions, and describe the development of the software tool RandoMice which can be used to improve the quality of preclinical studies by creating well-balanced experimental groups. Show less
Zonneveld, M.H.; Trompet, S.; Jukema, J.W.; Noordam, R. 2023
Prospective cohort studies have implied associations between blood levels of troponin T, troponin I, NT-proBNP, GDF15, dementia, and cognitive function, without providing evidence favoring... Show moreProspective cohort studies have implied associations between blood levels of troponin T, troponin I, NT-proBNP, GDF15, dementia, and cognitive function, without providing evidence favoring possible causality. We aimed to assess the causal associations of these cardiac blood biomarkers with dementia and cognition using two-sample Mendelian randomization (MR). Independent genetic instruments (p < 5e−7) for troponin T and I, N-terminal pro B-type natriuretic peptide (NT-proBNP) and growth-differentiation factor 15 (GDF15) were obtained from previously-performed genome-wide association studies of predominantly European ancestry. Summary statistics for gene-outcome associations in European-ancestry participants, for the two-sample MR analyses, were obtained for general cognitive performance (n = 257,842) and dementia (n = 111,326 clinically diagnosed and “proxy” AD cases, and 677,663 controls). Two-sample MR analyses were performed using inverse variance-weighted (IWV) analyses. Sensitivity analyses to evaluate horizontal pleiotropy included weighted median estimator, MR-Egger, and MR using cis-SNPs only. Using IVW, we did not find evidence for possible causal associations between genetically influenced cardiac biomarkers with cognition and dementia. For example, per standard deviation (SD) higher cardiac blood biomarker, the odds ratio for risk of dementia was 1.06 (95%CI 0.90; 1.21) for troponin T, 0.98 (95%CI 0.72; 1.23) for troponin I, 0.97 (95%CI 0.90; 1.06) for NT-proBNP and 1.07 (95%CI 0.93; 1.21) for GDF15. Sensitivity analyses showed higher GDF15 was significantly associated with higher dementia risk and worse cognitive function. We did not find strong evidence that cardiac biomarkers causally influence dementia risk. Future research should aim at elucidating the biological pathways through which cardiac blood biomarkers associate with dementia. Show less
Eenige, R. van; Ying, Z.X.; Tramper, N.; Wiebing, V.; Siraj, Z.; Boer, J.F. de; ... ; Kooijman, S. 2023
Background and aims: Combined agonism of the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon-like peptide-1 receptor (GLP1R) is superior to single GLP1R agonism in... Show moreBackground and aims: Combined agonism of the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon-like peptide-1 receptor (GLP1R) is superior to single GLP1R agonism in terms of glycemic control and lowering body weight in individuals with obesity and with or without type 2 diabetes mellitus. As both GIPR and GLP1R signaling have also been implicated in improving inflammatory responses and lipid handling, two crucial players in atherosclerosis development, here we aimed to investigate the effects of combined GIPR/GLP1R agonism in APOE*3-Leiden.CETP mice, a well-established mouse model for human-like lipoprotein metabolism and atherosclerosis development. Methods: Female APOE*3-Leiden.CETP mice were fed a Western-type diet (containing 16% fat and 0.15% cholesterol) to induce dyslipidemia, and received subcutaneous injections with either vehicle, a GIPR agonist (GIPFA-085), a GLP1R agonist (GLP-140) or both agonists. In the aortic root area, atherosclerosis development was assessed. Results: Combined GIPR/GLP1R agonism attenuated the development of severe atherosclerotic lesions, while single treatments only showed non-significant improvements. Mechanistically, combined GIPR/GLP1R agonism decreased markers of systemic low-grade inflammation. In addition, combined GIPR/GLP1R agonism markedly lowered plasma triglyceride (TG) levels as explained by reduced hepatic very-low-density lipoprotein (VLDL)-TG production as well as increased TG-derived fatty acid uptake by brown and white adipose tissue which was coupled to enhanced hepatic uptake of core VLDL remnants. Conclusions: Combined GIPR/GLP1R agonism attenuates atherosclerosis severity by diminishing inflammation and increasing VLDL turnover. We anticipate that combined GIPR/GLP1R agonism is a promising strategy to lower cardiometabolic risk in humans. Show less
The prevalence of cardiovascular diseases has increased in the last decennia. This thesis studied the potential relationship between oxidative stress and cardiovascular diseases. The first part of... Show moreThe prevalence of cardiovascular diseases has increased in the last decennia. This thesis studied the potential relationship between oxidative stress and cardiovascular diseases. The first part of the thesis focused on anti-oxidants, which are scavengers that protect against oxidative damage. We studied the association between several lifestyle factors, diet, physical activity, sleep, alcohol intake and smoking, and antioxidant levels both in blood and urine. Subsequently, we investigated whether a higher concentration of antioxidants leads to a decrease in ischaemic stroke occurrence. Next, we aimed to study a possible cause of oxidative damage and its effect on cardiovascular disease. Mitochondrial dysfunction is one of the mechanisms that may underly this effect. Mitochondria are an important source of Reactive Oxygen Species (ROS), as an inevitable byproduct of their essential role in energy production. A disbalance in ROS production and scavenging might result in oxidative damage. Thus, we investigated the causal association between mitochondrial dysfunction and stroke using the Mendelian Randomization method. Finally, we studied how socio-demographic traits could modify the causal association between CVD risk factors and coronary artery disease. Show less
Cardiovascular disease is the leading cause of death in the world. Therefore, there is an increasing need for accurate and efficient cardiovascular risk assessment to optimize cardiovascular... Show moreCardiovascular disease is the leading cause of death in the world. Therefore, there is an increasing need for accurate and efficient cardiovascular risk assessment to optimize cardiovascular treatment. The aorta plays a central role in the cardiovascular system, transporting blood to various organ systems while absorbing the pulsatile pressure of the cardiac output. Aortic stiffness is a marker of vascular aging and has shown to be an independent marker for cardiovascular risk. Additionally, enlarged aortic dimensions are linked to an increased risk of rupture. MRI is capable of providing accurate information on aortic morphology, stiffness and blood flow patterns.In this thesis we expanded the potential clinical utility of MRI-based measures of aortic morphology and function in the assessment of cardiovascular risk and further unravelled complex cardiovascular systemic interactions using MRI. We provided standardized methods and reference values for fundamental MRI-based measures of aortic morphology and function, explored new methods to make PWV more accessible, evaluated the prognostic value of MRI-based measures of aortic morphology and function and explored systemic interactions of cardiovascular function with obesity as well as the brain. These studies contribute to more accurate and accessible cardiovascular risk assessment, which eventually can lead to improved cardiovascular treatment. Show less
In the first part of this thesis we focus on the genetic determinants of lipid metabolism as atherogenic dyslipidemia is major component of cardiometabolic disease and consequently of CVD. In the... Show moreIn the first part of this thesis we focus on the genetic determinants of lipid metabolism as atherogenic dyslipidemia is major component of cardiometabolic disease and consequently of CVD. In the second part of the thesis, we study the age-related changes of cardiometabolic risk factors over the life course across four generations. In this thesis, we aimed to gain new insights into the underlying pathophysiology of cardiometabolic disease and the long-term and cumulative exposure of its risk factors over the life course, thereby facilitating the search for preventive and curative strategies of cardiometabolic disease. In the first part of this thesis, we focused on the genetic determinants of lipid metabolism during both fasting and postprandial states. In the second part, we studied the age-related changes of cardiometabolic risk factors, in particular of body weight, overweight and obesity, over the life course across four generations. An important finding of the thesis is that obesity has worsened in the younger generations, reaching almost double the prevalence of older generations. However, after midlife the levels of obesity levelled off, which could be a reason why the adverse shift in obesity was not associated with unfavourable changes in cardiometabolic risk factors. We also found out that some genes effect body weight differently at different ages, which suggests that gene-environment interactions play an important role in body weight and consequently in obesity. Show less
Background Socioeconomic status and ethnicity are not explicitly incorporated as risk factors in the four SCORE2 cardiovascular disease (CVD) risk models developed for country-wide implementation... Show moreBackground Socioeconomic status and ethnicity are not explicitly incorporated as risk factors in the four SCORE2 cardiovascular disease (CVD) risk models developed for country-wide implementation across Europe (low, moderate, high and very-high model). The aim of this study was to evaluate the performance of the four SCORE2 CVD risk prediction models in an ethnic and socioeconomic diverse population in the Netherlands.Methods The SCORE2 CVD risk models were externally validated in socioeconomic and ethnic (by country of origin) subgroups, from a population-based cohort in the Netherlands, with GP, hospital and registry data. In total 155,000 individuals, between 40 and 70 years old in the study period from 2007 to 2020 and without previous CVD or diabetes were included. Variables (age, sex, smoking status, blood pressure, cholesterol) and outcome first CVD event (stroke, myocardial infarction, CVD death) were consistent with SCORE2. Findings 6966 CVD events were observed, versus 5495 events predicted by the CVD low-risk model (intended for use in the Netherlands). Relative underprediction was similar in men and women (observed/predicted (OE-ratio), 1.3 and 1.2 in men and women, respectively). Underprediction was larger in low socioeconomic subgroups of the overall study population (OE-ratio 1.5 and 1.6 in men and women, respectively), and comparable in Dutch and the combined "other ethnicities" low socioeconomic subgroups. Underprediction in the Surinamese subgroup was largest (OE-ratio 1.9, in men and women), particularly in the low socioeconomic Surinamese subgroups (OE-ratio 2.5 and 2.1 in men and women). In the subgroups with underprediction in the low-risk model, the intermediate or high-risk SCORE2 models showed improved OE-ratios. Discrimination showed moderate performance in all subgroups and the four SCORE2 models, with C-statistics between 0.65 and 0.72, similar to the SCORE2 model development study.Interpretation The SCORE 2 CVD risk model for low-risk countries (as the Netherlands are) was found to underpredict CVD risk, particularly in low socioeconomic and Surinamese ethnic subgroups. Including socioeconomic status and ethnicity as predictors in CVD risk models and implementing CVD risk adjustment within countries is desirable for adequate CVD risk prediction and counselling. Show less
