Protection of diabetes in aortic abdominal aneurysm: Are antidiabetics the real effectors?

Abdominal Aortic Aneurysm and Liver Fibrosis: Clinical Evidence and Molecular Pathomechanisms

To stimulate further research, this review summarizes studies linking liver fibrosis with the risk of abdominal aortic aneurysms (AAA). AAA is defined as a permanently weakened and dilated abdominal aorta, which develops due to inflammation of the tunica media, activation of the renin-angiotensin-aldosterone system, immune system activation, and coagulation disorders. Typically asymptomatic, AAA is often incidentally detected through imaging done for abdominal symptoms or as part of screening programs. AAA follows a variable course and has a mortality rate strongly dependent on age and sex. Risk factors for AAA include age, male sex, ethnicity, family history of AAA, lifestyle habits, arterial hypertension, dyslipidemia, and comorbid atherosclerotic cardiovascular disease. Conversely, individuals with type 2 diabetes, female sex, and certain ethnicities are at a reduced risk of AAA. Liver fibrosis, resulting from chronic liver diseases owing to varying etiologies, is increasingly recognized as a potential contributor to AAA development. Evidence increasingly indicates that metabolic dysfunction-associated steatotic liver disease (MASLD) and other chronic liver conditions may intensify inflammatory pathways shared with AAA, thereby potentially exacerbating AAA progression. This review specifically examines the epidemiology and risk factors associated with the link between AAA and liver fibrosis. It also highlights potential pathomechanisms, including systemic inflammation, oxidative stress, and extracellular matrix remodeling, which may contribute to both conditions. Although these findings underscore significant overlaps in risk profiles, additional research is needed to clarify whether type 2 diabetes, female sex, and certain ethnicities truly confer protection against AAA or if this association is influenced by other confounding variables. Ultimately, addressing these open questions will help guide targeted therapeutic interventions and the identification of novel biomarkers to predict disease progression.

Associations between Type 2 Diabetes Mellitus, Metabolic Traits, and Abdominal Aortic Aneurysm: A Cross-Ethnic Mendelian Randomization Analysis

BACKGROUND

Evidence suggests that type 2 diabetes mellitus (T2DM) may protect from abdominal aortic aneurysm (AAA). However, it is unclear whether a causal relationship exists between these 2 conditions and, if so, whether it remains consistent among racial groups.

METHODS

Cross-ethnic Mendelian randomization (MR) was used to examine the causal relationships between T2DM, metabolic traits, and AAA. Inverse variance weighted (IVW) was the primary analysis tool, supplemented by MR-Egger, weighted median, and MR Pleiotropy RESidual Sum and Outlier. Heterogeneity and horizontal pleiotropy were assessed using the Cochran's Q test and MR-Egger intercept, respectively.

RESULTS

According to IVW, an inverse correlation between T2DM and AAA was detected in Europeans (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.84-0.99; P = 0.034) and East Asians (OR 0.87, 95% CI 0.77-0.99; P = 0.038). Fasting glucose was inversely associated with AAA in Europeans (OR 0.56, 95% CI 0.33-0.96; P = 0.034) but not in East Asians. In Europeans, fasting insulin was a risk factor for AAA (OR 3.03, 95% CI 1.53-6.01; P = 0.001), while 2-hour glucose was protective (OR 0.67, 95% CI 0.49-0.91; P = 0.011). Glycated hemoglobin (HbA1c) had no effect. Insufficient instrumental variables prevented the evaluation of the relationships of fasting insulin, HbA1c, and 2-hour glucose with AAA in East Asians.

CONCLUSIONS

T2DM protects against AAA in Europeans and East Asians. The effects of different glucose metabolism characteristics on AAA may inform AAA treatment.

Aortic aneurysm: Correlations with phenotypes associated with connective tissue dysplasia

An aortic aneurysm is a localized enlargement that exceeds the normal diameter of the vessel by 50 %, posing a risk due to the likelihood of rupture. The cause of aortic aneurysm, especially in young people, is connective tissue dysplasia, a condition characterized by defects in the assembly of collagen and elastin proteins, leading to changes in elastic properties and disruption of the formation of organs and their systems. The article presents data confirming the relationship between many morphological manifestations of connective tissue dysplasia (e.g., funnel-shaped deformation of the sternum, scoliosis of the thoracic spine, abdominal hernias, arterial tortuosity, striae of atypical localization) and the risk of aortic aneurysm formation. The literature suggests that the identified combinations of some external manifestations of connective tissue dysplasia deserve special attention and may be constitutional markers for the possible development of aortic aneurysm, which is a promising direction for further research in this area.

Diabetes and Abdominal Aortic Aneurysm: Is the Protective Effect on AAA Due to Antidiabetic Medications Alone, Due to the Disease Alone, or Both?

Diabetes is a metabolic disease that may result in multiple microvascular and macrovascular diseases. Interestingly, many studies have demonstrated the inverse relationship between diabetes and the development and expansion of abdominal aortic aneurysm (AAA). One hypothesis is that the aortic wall stiffness resulting from hyperglycemia and advanced glycation end products could delay the development and growth of AAA. Other studies have proposed that the concurrent use of antidiabetic medications which promote anti-inflammatory cytokines while hindering pro-inflammatory cytokines may potentially be the reason for this protective effect of diabetes on AAA. Contrastingly, the presence of diabetes has been found to have a negative effect on the outcome of AAA following its repair which may be due to elevated blood glucose negatively affecting the healing process. The current literature has also demonstrated the negative impact of the use of fluoroquinolones on AAA. This comprehensive review critically reviewed and summarized the role of diabetes, anti-diabetes medications and fluoroquinolones on AAA, and on the effect of diabetes and certain anti-diabetes medications on outcomes following its repair.

PINK1 dominated mitochondria associated genes signature predicts abdominal aortic aneurysm with metabolic syndrome

Abdominal aortic aneurysm (AAA) is typically asymptomatic but a devastating cardiovascular disorder, with overall mortality exceeding 80 % once it ruptures. Some patients with AAA may also have comorbid metabolic syndrome (MS), suggesting a potential common underlying pathogenesis. Mitochondrial dysfunction has been reported as a key factor contributing to the deterioration of both AAA and MS. However, the intricate interplay between metabolism and mitochondrial function, both contributing to the development of AAA, has not been thoroughly explored. In this study, we identified candidate genes related to mitochondrial function in AAA and MS. Subsequently, we developed a nomoscore model comprising hub genes (PINK1, ACSL1, CYP27A1, and SLC25A11), identified through the application of two machine learning algorithms, to predict AAA. We observed a marked disparity in immune infiltration profiles between high- and low-nomoscore groups. Furthermore, we confirmed a significant upregulation of the expression of the four hub genes in AAA tissues. Among these, ACSL1 showed relatively higher expression in LPS-treated RAW264.7 cell lines, while CYP27A1 exhibited a notable decrease. Moreover, SLC25A11 displayed a significant upregulation in AngII-treated VSMCs. Conversely, the expression level of PINK1 declined in LPS-stimulated RAW264.7 cell lines but significantly increased in AngII-treated VSMCs. In vivo experiments revealed that the activation of PINK1-mediated mitophagy inhibited the development of AAA in mice. In this current study, we have innovatively identified four mitochondrial function-related genes through integrated bioinformatic analysis. This discovery sheds light on the regulatory mechanisms and unveils promising therapeutic targets for the comorbidity of AAA and MS.

Yersinia enterocolitica Bacteremia Associated with a Ruptured Abdominal Aortic Aneurysm: A Case Report with Literature Review

Yersinia enterocolitica is a foodborne pathogen, mainly associated with disorders involving the gastrointestinal tract, including diarrhea, ileitis, and mesenteric lymphadenitis. Extraintestinal presentation is uncommon in healthy individuals, but bacteremia is reported in immunocompromised hosts. We present a 74-year-old male with Y. enterocolitica serogroup O:3 bacteremia who complicated to rupture of an abdominal aortic aneurysm. With the current case report, we aimed to emphasize the association of Y. enterocolitica bacteremia with abdominal aortic aneurysm rupture. Better surveillance is needed, not only to reduce morbidity and mortality but also to update current epidemiological data on the incidence of such associations.

Diabetic microvascular disease in non-classical beds: the hidden impact beyond the retina, the kidney, and the peripheral nerves

Diabetes microangiopathy, a hallmark complication of diabetes, is characterised by structural and functional abnormalities within the intricate network of microvessels beyond well-known and documented target organs, i.e., the retina, kidney, and peripheral nerves. Indeed, an intact microvascular bed is crucial for preserving each organ's specific functions and achieving physiological balance to meet their respective metabolic demands. Therefore, diabetes-related microvascular dysfunction leads to widespread multiorgan consequences in still-overlooked non-traditional target organs such as the brain, the lung, the bone tissue, the skin, the arterial wall, the heart, or the musculoskeletal system. All these organs are vulnerable to the physiopathological mechanisms that cause microvascular damage in diabetes (i.e., hyperglycaemia-induced oxidative stress, inflammation, and endothelial dysfunction) and collectively contribute to abnormalities in the microvessels' structure and function, compromising blood flow and tissue perfusion. However, the microcirculatory networks differ between organs due to variations in haemodynamic, vascular architecture, and affected cells, resulting in a spectrum of clinical presentations. The aim of this review is to focus on the multifaceted nature of microvascular impairment in diabetes through available evidence of specific consequences in often overlooked organs. A better understanding of diabetes microangiopathy in non-target organs provides a broader perspective on the systemic nature of the disease, underscoring the importance of recognising the comprehensive range of complications beyond the classic target sites.