Association between Diabetes and Risk of Aortic Dissection: A Case-Control Study in a Chinese Population

Aortic Dissection Incidence and Risk Factor Analysis: Findings from the China Kadoorie Biobank

OBJECTIVE

Data on the incidence of aortic dissection (AD) from population based prospective studies are scarce and its risk factors are not well studied in China. The aim of this study was to investigate the relatively accurate incidence of AD in ten regions of China and to identify its potential risk factors using a population based prospective study.

METHODS

Data from a prospective cohort study involving ∼510 000 middle aged adults in ten regions of China from 2004 - 2008 (the China Kadoorie Biobank) were used. The incidence of AD was calculated and the association between potential risk factors (body mass index [BMI], hypertension, and diabetes) and the occurrence of AD was evaluated using competing risk analysis.

RESULTS

The study included 512 724 participants (59.0% female, median age 51.5 years). During a median follow up of 121 months, 119 participants developed AD. The incidence of AD was 2.35 (95% confidence interval [CI] 1.93 - 2.77), 3.97 (95% CI 3.10 - 4.83), and 1.25 (95% CI 0.86 - 1.65) per 100 000 person years for the whole cohort, male participants, and female participants, respectively. Competing risk analysis identified female sex (hazard ratio [HR] 0.35, 95% CI 0.24 - 0.52; p < .001) and hypertension (HR 6.21, 95% CI 3.94 - 9.80; p < .001) as independent predictors of AD. BMI, diabetes, and random blood glucose were not associated with AD.

CONCLUSION

In contrast to previous data and clinical observations, there was no significant correlation between diabetes (or random blood glucose) or BMI and the occurrence of AD. Male sex and hypertension were independently associated with the occurrence of AD.

Diabetes does not increase in-hospital or short-term mortality in patients undergoing surgical repair for type A aortic dissection: insight from the national readmission database

BACKGROUND

Previous studies have reported a protective effect of type 2 diabetes on the incidence and progression of aortic aneurysms. We investigated whether this protective effect extends to aortic dissections.

METHODS

Data from the US Nationwide Readmission Database (2016-2019) were analyzed. Patients admitted for open surgery repair of acute type A aortic dissection (TAAD) were initially analyzed (index group). Those discharged alive were followed for up to 30 days (readmission group). The co-primary outcomes were in-hospital and 30-day mortality.

RESULTS

Between 2016 and 2019, 7,324 patients were admitted for open surgical repair of acute TAAD, of whom 965 (13.2%) had diabetes. Patients with diabetes were older and had a higher prevalence of obesity, hypertension, smoking, dyslipidemia, and chronic kidney disease (CKD). 15.2% of patients with diabetes and 14.6% without diabetes died; hence, diabetes did not have a significant impact on in-hospital mortality (adjusted odd ratio [aOR] = 1.02 [0.84-1.24]). Similarly, diabetes was not associated with a higher adjusted risk of atrial fibrillation (aOR = 1.03 [0.89-1.20]), stroke (aOR = 0.83 [0.55-1.26]), cardiogenic shock (aOR = 1.18 [0.98-1.42]), but increased the risk of acute renal failure (aOR = 1.20 [1.04-1.39]). Within 30 days of discharge, 154 (15.9%) patients with diabetes and 952 (15%) from the non-diabetes group were readmitted. Readmitted patients with diabetes were older and had a higher prevalence of cardiovascular comorbidities. We didn't observe any significant difference in the adjusted risk of 30-day mortality between the diabetes and non-diabetes groups (adjusted hazard ratio [aHR] = 0.81 [0.41-1.60]). However, diabetes was associated with a lower risk of readmission (aHR = 0.81 [0.68-0.97]). Age was the most significant predictor of all outcomes. CKD was the most significant predictor of 30-day mortality, with the risk increasing five-fold in patients with diabetes (HR = 5.58 [2.58-6.62]. Cardiovascular-related conditions were the most common causes of readmission in both groups. However, respiratory-related conditions were more prevalent in the diabetes group compared to the non-diabetes group (19.5% vs. 13%, respectively, p = 0.032).

CONCLUSIONS

Diabetes does not increase in-hospital or short-term mortality in patients undergoing surgical repair for Type A aortic dissection.

Diabetes is not a negative prognostic factor for 30-days mortality after surgery for acute type A aortic dissection

Background

The correlation between diabetes and aortic dissection is not fully understood yet, although in literature many studies have suggested that there may be an association between the two conditions. The purpose of this study is to evaluate whether diabetes represents a short- and long-term risk factor for mortality from type A acute aortic dissection.

Materials and methods

A total of 340 patients with the diagnosis of type A acute aortic dissection underwent aortic surgery between January 2002 and March 2023. The sample was divided into 2 cohorts according to the presence of diabetes (n = 34) or not (n = 306).

Results

The mean age was 66 (±12.4) years and 60.9% were male. The primary endpoint was 30-day mortality. Hospital mortality was 12 (35.3%) for the diabetes group and 70 (22.9%) for nondiabetes group (P = 0.098). Overall survival at 10 years was 48.3% [95% confidence interval (CI): 41.6-54.7%], while the 10-year survival for people with diabetes was 29.5% (95% CI: 13.2-47.9%) and for nondiabetes group 50.6% (95% CI: 43.4-57.3%) (Log-rank, P = 0.024).

Conclusion

Diabetes was not found to be a risk factor associated with 30-day mortality in patients undergoing surgery for type A acute aortic dissection. It was a risk factor for long-term survival, but this may be related to diabetes complications.

Genetic predisposition to type 2 diabetes mellitus and aortic dissection: a Mendelian randomisation study

Background

This Mendelian randomization (MR) study aimed to explore the causal relationship between the genetic predisposition to type 2 diabetes mellitus (T2DM) and aortic dissection (AD), and to assess associations with genetically predicted glycemic traits. The study sought to verify the inverse relationship between T2DM and AD using a more robust and unbiased method, building on the observational studies previously established.

Materials and methods

The study employed a two-sample and multivariable MR approach to analyze genetic data from the DIAbetes Meta-ANalysis of Trans-Ethnic association studies (DIAMANTE) with 74,124 cases and 824,006 controls, and the Meta-Analyses of Glucose and Insulin-Related Traits Consortium (MAGIC) involving up to 196,991 individuals. For AD data, FinnGen Release 10 was used, including 967 cases and 381,977 controls. The research focused on three foundational MR assumptions and controlled for confounders like hypertension. Genetic instruments were selected for their genome-wide significance, and multiple MR methods and sensitivity analyses were conducted.

Results

The study revealed no significant effect of genetic predisposition to T2DM on the risk of AD. Even after adjusting for potential confounders, the results were consistent, indicating no causal relationship. Additionally, glycemic traits such as fasting glucose, fasting insulin, and HbA1c levels did not show a significant impact on AD susceptibility. The findings remained stable across various MR models and sensitivity analyses. In contrast, genetic liability to T2DM and glycemic traits showed a significant association with coronary artery disease (CAD), aligning with the established understanding.

Conclusion

Contrary to previous observational studies, this study concludes that genetic predisposition to T2DM does not confer protection against AD. These findings underscore the imperative for further research, particularly in exploring the preventative potential of T2DM treatments against AD and to facilitate the development of novel therapeutic interventions.

A nomogram prediction model for short-term aortic-related adverse events in patients with acute Stanford type B aortic intramural hematoma: development and validation

Background

This study is to examine the factors associated with short-term aortic-related adverse events in patients with acute type B aortic intramural hematoma (IMH). Additionally, we develop a risk prediction nomogram model and evaluate its accuracy.

Methods

This study included 197 patients diagnosed with acute type B IMH. The patients were divided into stable group (n = 125) and exacerbation group (n = 72) based on the occurrence of aortic-related adverse events. Logistic regression and the Least Absolute Shrinkage and Selection Operator (LASSO) method for variables based on baseline assessments with significant differences in clinical and image characteristics were employed to identify independent predictors. A nomogram risk model was constructed based on these independent predictors. The nomogram model was evaluated using various methods such as the receiver operating characteristic curve, calibration curve, decision analysis curve, and clinical impact curve. Internal validation was performed using the Bootstrap method.

Results

A nomogram risk prediction model was established based on four variables: absence of diabetes, anemia, maximum descending aortic diameter (MDAD), and ulcer-like projection (ULP). The model demonstrated a discriminative ability with an area under the curve (AUC) of 0.813. The calibration curve indicated a good agreement between the predicted probabilities and the actual probabilities. The Hosmer-Lemeshow goodness of fit test showed no significant difference (χ 2 = 7.040, P = 0.532). The decision curve analysis (DCA) was employed to further confirm the clinical effectiveness of the nomogram.

Conclusion

This study introduces a nomogram prediction model that integrates four important risk factors: ULP, MDAD, anemia, and absence of diabetes. The model allows for personalized prediction of patients with type B IMH.

Causal relationship between type 2 diabetes mellitus and aortic dissection: insights from two-sample Mendelian randomization and mediation analysis

Objective

Some evidence suggests a reduced prevalence of type 2 diabetes mellitus (T2DM) in patients with aortic dissection (AD), a catastrophic cardiovascular illness, compared to general population. However, the conclusions were inconsistent, and the causal relationship between T2DM and AD remains unclear.

Methods

In this study, we aimed to explore the causal relationship between T2DM and AD using bidirectional Mendelian randomization (MR) analysis. Mediation MR analysis was conducted to explore and quantify the possible mediation effects of 1400 metabolites in T2DM and AD.

Results

The results of 26 datasets showed no causal relationship between T2DM and AD (P>0.05). Only one dataset (ebi-a-GCST90006934) showed that T2DM was a protective factor for AD (I9-AORTDIS) (OR=0.815, 95%CI: 0.692-0.960, P=0.014), and did not show horizontal pleiotropy (P=0.808) and heterogeneity (P=0.525). Vanillic acid glycine plays a mediator in the causal relationship between T2DM and AD. The mediator effect for vanillic acid glycine levels was -0.023 (95%CI: -0.066-0.021).

Conclusion

From the perspective of MR analysis, there might not be a causal relationship between T2DM and AD, and T2DM might not be a protective factor for AD. If a causal relationship does exist between T2DM and AD, with T2DM serving as a protective factor, vanillic acid glycine may act as a mediator and enhance such a protective effect.

Risk factors for in-hospital death in 2,179 patients with acute aortic dissection

Background

This study aims to investigate the risk factors for in-hospital death in patients with acute aortic dissection (AAD) and to provide a straightforward prediction model to assist clinicians in determining the outcome of AAD patients.

Methods

Retrospective analysis was carried out on 2,179 patients admitted for AAD from March 5, 1999 to April 20, 2018 in Wuhan Union Hospital, China. The risk factors were investigated with univariate and multivariable logistic regression analysis.

Results

The patients were divided into two groups: Group A, 953patients (43.7%) with type A AAD; Group B, 1,226 patients (56.3%) with type B AAD. The overall in-hospital mortality rate was 20.3% (194/953) and 4% (50/1,226) in Group A and B respectively. The multivariable analysis included the variables that were statistically significant predictors of in-hospital death (P < 0.05). In Group A, hypotension (OR = 2.01, P = 0.001) and liver dysfunction (OR = 12.95, P < 0.001) were independent risk factors. Tachycardia (OR = 6.08, P < 0.001) and liver dysfunction (OR = 6.36, P < 0.05) were independent risk factors for Group B mortality. The risk factors of Group A were assigned a score equal to their coefficients, and the score of -0.5 was the best point of the risk prediction model. Based on this analysis, we derived a predictive model to help clinicians determine the prognosis of type A AAD patients.

Conclusions

This study investigate the independent factors associated with in-hospital death in patients with type A or B aortic dissection, respectively. In addition, we develop the prediction of the prognosis for type A patients and assist clinicians in choosing treatment strategies.

Dose-dependent relationship of blood pressure and glycaemic status with risk of aortic dissection and aneurysm

AIMS

Data on the dose-dependent association of blood pressure (BP) and fasting plasma glucose (FPG) level with the risk of aortic dissection (AD) and aortic aneurysm (AA) are limited.

METHODS AND RESULTS

This observational cohort study included 3 358 293 individuals registered in a health checkup and claims database in Japan [median age, 43 (36-51) years; 57.2% men]. Individuals using BP- or glucose-lowering medications or those with a history of cardiovascular disease were excluded. In a mean follow-up period of 1 199 ± 950 days, 1 095 and 2 177 cases of AD and AA, respectively, were recorded. Compared with normal/elevated BP, hazard ratios (HRs) of Stage 1 and Stage 2 hypertension were 1.89 [95% confidence interval (CI): 1.60-2.22] and 5.87 (95% CI: 5.03-6.84) for AD and 1.37 (95% CI: 1.23-1.52) and 2.17 (95% CI: 1.95-2.42) for AA, respectively. Compared with normal FPG level, HRs of prediabetes and diabetes were 0.82 (95% CI: 0.71-0.94) and 0.48 (95% CI: 0.33-0.71) for AD and 0.94 (95% CI: 0.85-1.03) and 0.61 (95% CI: 0.47-0.79) for AA, respectively. The cubic spline demonstrated that the risk of AD and AA increased with increasing BP but decreased with increasing FPG level. Contour plots using generalized additive models showed that higher systolic BP and lower FPG level were associated with an elevated risk of AD and AA.

CONCLUSIONS

Our analysis showed a dose-dependent increase in the risk of AD or AA associated with BP and a similar decrease associated with FPG, and also suggested a potential interaction between hypertension and hyperglycaemia in the development of AD and AA.

Long‐Term Risks of Stroke in Patients With Type A Aortic Dissection: A Nationwide Cohort Study

Background

Patients with type A aortic dissection (TAAD) have a high short‐term risk of stroke. However, whether patients with TAAD have an increased long‐term risk of stroke is still undetermined, and our study aims to address this knowledge gap.

Methods and Results

A nationwide retrospective cohort study was conducted using Taiwan's National Health Insurance Research Database. We included patients with TAAD as well as age‐ and sex‐matched aortic disease–free individuals between 2003 and 2016. Inverse probability of treatment weighting was performed to balance patient characteristics between the groups. The primary outcome was the development of stroke, regardless of subtype; the secondary outcomes were the risk of developing either ischemic or hemorrhagic stroke. The hazard ratios (HRs) of stroke were estimated using the Cox proportional hazards model. After inverse probability of treatment weighting, 3556 and 7023 patients were categorized into the TAAD and aortic disease–free cohorts, respectively. The mean follow‐up period was 5.71 years. The HRs for overall, ischemic, and hemorrhagic strokes in the TAAD cohort were 3.01 (95% CI, 2.40–3.78), 3.18 (95% CI, 2.47–4.10), and 2.32 (95% CI, 1.58–3.41), respectively, compared with the aortic disease–free cohort. Consistent trends of higher stroke risk in patients with TAAD were revealed in the analyses stratified by age; sex; antiplatelet use; and history of hypertension, diabetes, or dyslipidemia.

Conclusions

Our study findings revealed that patients with TAAD had an increased long‐term risk of both ischemic and hemorrhagic strokes. Further studies are warranted to establish optimal strategies for stroke prevention in these patients.

Frozen elephant trunk in acute type A aortic dissections: frontiers and challenges

Acute type A aortic dissection (ATAAD), a surgical emergency, has high mortality and morbidity. More than half of the patients die within 2 weeks and the 30-day mortality is 90%. Frozen elephant trunk in ATAAD addresses the primary and secondary goals - resection of the primary tear in the ascending aorta and promoting remodelling in the downstream aorta. Though the literature supports this fact, in reality these literatures emerge from high-volume centres. But in the "real world" most of the ATAAD are operated on in the low-volume centres. Furthermore, in India, there are unique challenges including the financial burden, transport, emergent availability of the hybrid prosthesis and aortic supercentres.

Exploring the Correlation and Protective Role of Diabetes Mellitus in Aortic Aneurysm Disease

Introduction: Diabetes mellitus is recognised as a significant risk factor for cardiovascular and peripheral vascular disease, as the abnormal metabolic state increases the risk for atherosclerosis, occlusive arterial disease and vascular dysfunction. There have been reports of potential association across the literature that illustrates a link between diabetes mellitus and aortic aneurysm, with the former having a protective role on the development of the latter.

Methods: A thorough literature search was performed through electronic databases, to provide a comprehensive review of the study's reporting on the association of diabetes mellitus and aortic aneurysm, discussing the mechanisms that have been reported; furthemore, we reviewed the reports of the impact of oral hypoglycameic agents on aortic aneurysms.

Results: Various proposed mechanisms are involved in this protective process including endothelial dysfunction, chronic hyperglycemia and insulin resistance. The evidence suggests a negative association between these disease process, with prevelance of diabetes mellitus resulting in lower rates of aortic aneurysm, via its protective mechanistic action. The increase in advanced glycation end products, increased arterial stiffness and vascular remodelling seen in diabetes, was found to have a profound impact on aneurysm development, its slow progression and lower rupture rate in these individuals. This review has also highlighted the role of oral hypoglycaemic agents having a protective effect against AA disease.

Conclusion: A decrease in development, progression and mortality from aortic aneurysms as well as reduced rates of dissection, have been observed in those with diabetes. This review has provided a comprehensive insight on the effect of diabetes and its physiological processes, and elements of its con-committant treatment, having a protective role against these aortic diseases.

Synthesis of multidimensional pathophysiological process leading to type A aortic dissection: a narrative review

Objective

This review aims to synthesize the existing knowledge on the etiological process leading to type A aortic dissection (TAAD) and to clarify the relationship between mechanical, biochemical, and histopathological processes behind the aortic disease.

Background

Extensive research has previously identified several risk factors for TAAD as well as pathological mechanisms leading to TAAD. However, due to the complexity of the pathological process and limited knowledge on the relationships between distinct pathomechanisms leading to TAAD, the ability to identify the patients at high risk for TAAD has been poor.

Methods

PubMed (National Library of Medicine) database was searched for suitable literature. The most relevant articles focusing on anatomy, histopathology, physiology, and mechanics of ascending aorta and aortic diseases were reviewed.

Conclusions

Pathophysiology of the TAAD is related to biochemical and histological as well as mechanical and hemodynamic alterations leading to a degeneration of the aortic wall via inflammatory response. The degradative mechanisms of aortic wall structures and the mechanical forces, to which the wall is predisposed, are interrelated and influence one another. The relativity between the factors influencing aortic wall strength and healing capacity, and factors influencing mechanical stress on the aortic wall suggest that the risk of TAAD is not a linear but rather a dynamic phenomenon. Accounting for the dynamical property of the aortic disease in assessing the need for preventive surgical aortic reconstruction may provide a wider perspective in identifying patients at risk of TAAD and in planning preventive medical therapies.

The novel hybrid polycarbonate polyurethane / polyester three-layered large-diameter artificial blood vessel

BACKGROUND

The most common materials of artificial blood vessels are polyethylene terephthalate and polytetrafluoroethylene. But polycarbonate polyurethane (PCU) is an ideal material for vascular prostheses because of their excellent characteristics. As far as we know, our artificial blood vessel is the first type of hybrid PCU/polyester three-layered large-diameter artificial blood vessel in the world.

OBJECTIVE

The purpose of this preclinical animal experiment is to evaluate the hemocompatibility, histocompatibility, effectiveness, and safety of the three-layered large-diameter artificial blood vessel in sheep.

METHODS

The artificial blood vessels took place of the initial segments of the sheep's thoracic aorta by end-to-end anastomosis.

RESULTS

All of the 14 sheep are male, their average body weight (BW) was 30.57 ± 3.95 kg. All 14 artificial blood vessels successfully replaced the thoracic aortas. 5 sheep did not survive to the end of the experiment, while the remaining 9 sheep did. After the surgery, the blood biochemical and blood routine indicators fluctuate slightly within the normal range. The angiography showed that the implanted artificial blood vessels were unobstructed without obvious stenosis or expansion. 24 weeks after surgery, the lumen surfaces of the artificial blood vessels were covered by endothelia in different degrees, and the average endothelialization rate was 69.44% (range: 20% to 100%).

CONCLUSIONS

This artificial blood vessel is the first to use PCU in large-diameter artificial vascular grafts. It has excellent blood compatibility, wonderful biocompatibility, high endothelialization rate, and 100% patency.

Root Dilatation Is More Malignant Than Ascending Aortic Dilation

Background Data from the International Registry of Acute Aortic Dissection indicate that the guideline criterion of 5.5 cm for ascending aortic intervention misses many dissections occurring at smaller dimensions. Furthermore, studies of natural behavior have generally treated the aortic root and the ascending aorta as 1 unit despite embryological, anatomical, and functional differences. This study aims to disentangle the natural histories of the aforementioned aortic segments, allowing natural behavior to define specific intervention criteria for root and ascending segments of the aorta. Methods and Results Diameters of the aortic root and mid-ascending segment were measured separately. Long-term complications (dissection, rupture, and death) were analyzed retrospectively for 1162 patients with ascending thoracic aortic aneurysm. Cox regression analysis suggested that aortic root dilatation (P=0.017) is more significant in predicting adverse events than mid-ascending aortic dilatation (P=0.087). Short stature posed as a serious risk factor. The dedicated risk curves for the aortic root and the mid-ascending aorta revealed hinge points at 5.0 and 5.25 cm, respectively. Conclusions The natural histories of the aortic root and mid-ascending aorta are uniquely different. Dilation of the aortic root imparts a significant higher risk of adverse events. A diameter shift for intervention to 5.0 cm for the aortic root and to 5.25 cm for the mid-ascending aorta should be considered at expert centers.

Diabetes Mellitus Lowers the Risk of Aortic Dissection: a Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aimed to investigate the association between diabetes mellitus and aortic dissection.

METHODS

The PubMed and Embase databases were searched until December 2019 to identify all articles reporting diabetes mellitus and aortic dissection. The pooled odds ratio and 95% confidence interval were calculated using random-effects model.

RESULTS

A total of 14 articles with 15,794 participants, of which 2133 diabetes mellitus patients, were eligible and included in this meta-analysis. The data suggested that diabetes mellitus decreased the risk of aortic dissection. In the subgroup analysis, this association was significant in worldwide studies except for the Chinese cohort and in studies adjusted for confounding factors. The results were stable after sensitivity analysis and no evidence of publication bias was found among studies.

CONCLUSIONS

The result of this meta-analysis indicated that diabetes mellitus was associated with a lower risk of aortic dissection.

Effect of Glycation on Interlamellar Bonding of Arterial Elastin

BACKGROUND

Interlamellar bonding in the arterial wall is often compromised by cardiovascular diseases. However, several recent nationwide and hospital-based studies have uniformly reported reduced risk of thoracic aortic dissection in patients with diabetes. As one of the primary structural constituents in the arterial wall, elastin plays an important role in providing its interlamellar structural integrity.

OBJECTIVE

The purpose of this study is to examine the effects of glycation on the interlamellar bonding properties of arterial elastin.

METHODS

Purified elastin network was isolated from porcine descending thoracic aorta and incubated in 2 M glucose solution for 7, 14 or 21 days at 37 °C. Peeling and direct tension tests were performed to provide complimentary information on understanding the interlamellar layer separation properties of elastin network with glycation effect. Peeling tests were simulated using a cohesive zone model (CZM). Multiphoton imaging was used to visualize the interlamellar elastin fibers in samples subjected to peeling and direct tension.

RESULTS

Peeling and direct tension tests show that interlamellar energy release rate and strength both increases with the duration of glucose treatment. The traction at damage initiation estimated for the CZM agrees well with the interlamellar strength measurements from direct tension tests. Glycation was also found to increase the interlamellar failure strain of arterial elastin. Multiphoton imaging confirmed the contribution of radially running elastin fibers to resisting dissection.

CONCLUSIONS

Nonenzymatic glycation reduces the propensity of arterial elastin to dissection. This study also suggests that the CZM effectively describes the interlamellar bonding properties of arterial elastin.

Factors Affecting Outcomes in Acute Type A Aortic Dissection: A Systematic Review

Acute type A aortic dissection is a clinical emergency and is associated with significant morbidity and mortality rates if not managed promptly in specialised and high-volume centres. The mortality rate is increased by 1% for each hour delay in management; however, with advancement in clinical practice, diagnostic imaging and clinician awareness, this has been dramatically reduced to below 30% in most international centres. Not only timing of recognition of the pathology, but also other factors can significantly affect outcomes of such critical pathology. This includes, but is not limited to, age, extent of the pathology, existence of connective tissue disorders, hypertension, diabetes mellitus and surgeon experience. This narrative review will focus on current clinical practice and the evidence behind optimising each factor to minimise adverse outcomes in such high-risk cohort.

Reduced Long-Term Risk of Aortic Aneurysm and Aortic Dissection Among Individuals With Type 2 Diabetes Mellitus: A Nationwide Observational Study

BACKGROUND

No studies have examined long-term risks for aortic aneurysm (AA) and aortic dissection (AD) or mortality after AA or AD hospitalization among patients with type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

In this observational cohort study, we linked data for patients with T2DM in the Swedish National Diabetes Register, and 5 individually matched population-based control subjects (CSs) without diabetes mellitus (on the basis of sex, age, and county), to other national databases to capture hospitalizations and death. We examined the risk of hospitalization for AA and AD, as well as mortality risk after AA and AD using Kaplan-Meier curves and Cox regression hazards models. Data on 448 319 patients with T2DM and 2 251 015 CSs were obtained between 1998 and 2015. Mean follow-up time was 7.0 years for the T2DM group and 7.2 years for the CS group. Patients with T2DM had a relative risk reduction of 28% (hazard ratio, 0.72; 95% confidence interval, 0.68-0.76; P<0.0001) for AA and a 47% relative risk reduction (hazard ratio, 0.53; 95% confidence interval, 0.42-0.65; P<0.0001) for AD compared with CSs. Patients with T2DM had a relative risk reduction of 12% (hazard ratio, 0.88; 95% confidence interval, 0.82-0.94; P<0.0001) for mortality after hospitalization for AA, and unaltered risk (hazard ratio, 1.07; 95% confidence interval, 0.85-1.34; P=0.5859) for mortality after AD, up to 2 years compared with CSs.

CONCLUSIONS

Patients with T2DM had significantly reduced risks of AA and AD as well as reduced risk of mortality after hospitalization for AA, compared to CS. Data suggest that glycated cross-links in aortic tissue may play a protective role in the progression of aortic diseases among patients with T2DM.

Risk of aortic aneurysm and dissection in patients with autosomal-dominant polycystic kidney disease: a nationwide population-based cohort study

Although cardiovascular complications are the most common cause of death in patients with autosomal-dominant polycystic kidney disease (ADPKD), the incidence and risk of aortic aneurysm and dissection (AAD) in ADPKD remains unclear due to limited data and insufficient cases. We utilized the data from Taiwan National Health Insurance Research Database (NHIRD) to do a population-based cohort study (1997-2008). After excluding those patients with age <18 years old and initially concomitant diagnoses of end-stage renal disease and AAD, a total of 2076 ADPKD patients were selected from 1,000,000 of general population. Additionally, the non-ADPKD group was set up as comparison group in 1:10 ratio after matching with age, gender, income and urbanization (n=20760). The result showed that ADPKD group had higher frequency of comorbidities than non-ADPKD group. The frequency of AAD in ADPKD was significantly higher than in general population (0.92% v.s. 0.11%, p<0.0001). Of them, 58% of AAD were acute aortic dissection. In addition, Kaplan-Meier analysis demonstrated that cumulative incidence of AAD was remarkably higher in the ADPKD than non-ADPKD group (p<0.001). The mean time period from ADPKD diagnosis to AAD occurrence was 4.02±3.16 years. After adjusting for age, gender and comorbidities, the ADPKD patients had up to 5.49-fold greater risk for AAD occurrence as compared to non-ADPKD counterparts (95% CI 2.86-10.52, p<0.0001). Particularly, those patients with co-existing ADPKD and hypertension had very high risk for future development of AAD. In conclusion, the risk of AAD significantly increases in patients with ADPKD as compared with those of general population.

Therapeutics Targeting Drivers of Thoracic Aortic Aneurysms and Acute Aortic Dissections: Insights from Predisposing Genes and Mouse Models

Thoracic aortic diseases, including aneurysms and dissections of the thoracic aorta, are a major cause of morbidity and mortality. Risk factors for thoracic aortic disease include increased hemodynamic forces on the ascending aorta, typically due to poorly controlled hypertension, and heritable genetic variants. The altered genes predisposing to thoracic aortic disease either disrupt smooth muscle cell (SMC) contraction or adherence to an impaired extracellular matrix, or decrease canonical transforming growth factor beta (TGF-β) signaling. Paradoxically, TGF-β hyperactivity has been postulated to be the primary driver for the disease. More recently, it has been proposed that the response of aortic SMCs to the hemodynamic load on a structurally defective aorta is the primary driver of thoracic aortic disease, and that TGF-β overactivity in diseased aortas is a secondary, unproductive response to restore tissue function. The engineering of mouse models of inherited aortopathies has identified potential therapeutic agents to prevent thoracic aortic disease.

Autonomic remodeling may be responsible for decreased incidence of aortic dissection in STZ-induced diabetic rats via down-regulation of matrix metalloprotease 2

Background

Epidemiological studies reported that diabetic patients had a lower incidence of aortic dissection (AD), but the definite mechanism is unknown. We aim to investigate the possible protective effect of diabetes mellitus (DM) on AD formation with an emphasis on autonomic remodeling.

Methods

Streptozotocin (STZ) intraperitoneal injection was applied to induce diabetes, unilateral renal artery stenosis (URAS) together with β-amino propionitrile (BAPN) oral treatment was used to induce AD. Sixty SD rats were equally and randomly divided into four groups (normal group, DM group, URAS + BAPN oral treatment group, DM + URAS + BAPN oral treatment group). Rats were fed for 6 weeks, the number of AD was recorded and remained rats were sacrificed. Thoracic aorta were harvested, morphological changes were assessed. Expression of tyrosine hydroxylase (TH), choline acetylase (ChAT), matrix metalloprotease 2 (MMP2) and matrix metalloprotease 9 (MMP9) were evaluated.

Results

A total of 7 AD was noted in S + B group, DM rats did not develop AD. Diabetic rats had a lower incidence of AD (P < 0.01). In dissected aorta, collagen deposition increased while elastic fiber became fragmented. These pathological changes diminished in diabetic rats. Diabetic rats had a lower expression of ChAT (P < 0.01). URAS + BAPN treatment elevated expression of TH in normal rat and ChAT in diabetic rats (P < 0.001). Expression of MMP2 and MMP9 elevated in all the rats after URAS + BAPN, but the elevation range of MMP2 in diabetic rats was smaller (P < 0.001).

Conclusions

STZ-induced diabetic rats have a lower incidence of AD after URAS and BAPN treatment, this protective effect could be possibly attributed to autonomic innervation modification and possible related down-regulation of MMP2.

Negative Association of Diabetes With Thoracic Aortic Dissection and Aneurysm

We performed a meta-analysis to assess the association of diabetes mellitus (DM) with the presence of thoracic aortic dissection (TAD) and/or thoracic aortic aneurysm (TAA). MEDLINE and EMBASE were searched through December 2015 using PubMed and OVID. For each study, data regarding DM prevalence in both the TAD/TAA and control groups were used to generate unadjusted odds ratios (ORs) for DM and 95% confidence intervals (CIs). Alternatively, an unadjusted and/or adjusted OR was directly abstracted from each individual study. Eleven eligible studies enrolling a total of 47 827 participants were included. A primary pooled analysis of all the 11 studies demonstrated that TAD/TAA was associated with significantly lower DM prevalence than controls (OR, 0.43; 95% CI, 0.31-0.59; P < .00001). Separate pooled analyses of 6 TAD case studies and 4 TAA case studies demonstrated TAD (OR, 0.34; 95% CI, 0.19-0.61; P = .0003) and TAA (OR, 0.65; 95% CI, 0.45-0.94; P = .02) were associated with significantly lower DM prevalence than controls. In conclusion, DM may be negatively associated with the presence of TAD/TAA.