Occurrence Of Abdominal Aortic Aneurysm Research Articles

Macrophage inflammasome mediates hyperhomocysteinemia-aggravated abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a serious vascular disease with high mortality. Our previous study suggested that hyperhomocysteinemia (HHcy) exaggerates the occurrence of AAA. Here, we investigated whether macrophage inflammasome is involved in HHcy-aggravated AAA formation. Two independent HHcy-aggravated AAA models, perivascular calcium phosphate–treated C57BL/6 mice and angiotensin II (Ang II)–infused apolipoprotein E-deficient (ApoE−/−) mice were used. NLPR3, caspase 1, and interleukin-1β (IL-1β) levels were higher in aneurysmal lesions of both HHcy models compared to controls, preferentially in macrophages. Similarly, macrophage inflammasome activation was observed in vitro. Folic acid administration reversed the HHcy-accelerated AAA, with ameliorated activation of inflammasome in the tunica adventitia. Lentiviral silencing of NLRP3 significantly ameliorated HHcy-aggravated AAA formation. We observed increased mitochondrial production of reactive oxygen species (ROS) and energy switch from oxidative phosphorylation to glycolysis with excess Hcy in macrophages. Blocking mitochondrial ROS production in macrophages abolished inflammasome activation. Our study highlights the potential importance of macrophage inflammasome in the pathogenesis and development of HHcy-aggravated AAA.

SEPP1 gene variants and abdominal aortic aneurysm: gene association in relation to metabolic risk factors and peripheral arterial disease coexistence.

An inadequate selenium level is supposed to be a risk factor for cardiovascular diseases. However little is known about variation of the genes encoding selenium-containing proteins that would confirm the causality in these diseases. The aim of this study was to analyze the relationships between two functional variants of selenoprotein P gene (SEPP1 rs3877899G>A, rs7579G>A) and the occurrence of abdominal aortic aneurysm (AAA) and aortoiliac occlusive disease (AIOD), as well as their metabolic risk factors. In AAA, the rs3877899A allele was associated with higher systolic blood (P < .003) and pulse pressure (P < .003) values (recessive model), and with coexistence of peripheral arterial disease (PAD; carriers: P = .033). The other SEPP1 variants were associated with BMI values and influenced the risk of aortic diseases, depending on body weight. The strongest associations in the case-control analysis was found between the presence of the rs3877899G-rs7579G haplotype and development of AAA in overweight and obese subjects (OR = 1.80, 95%CI = 1.16–2.79, P = .008). The higher BMI values were correlated with lower age of AAA patients and larger size of aneurysm. Our results suggests the potential role of the selenoprotein P in pathogenesis of AAA. Future studies should consider the role of the rs3877899G-rs7579G haplotype as a risk factor for aggressive-growing AAAs.

Abdominal aortic aneurysm screening program in Poland.

BackgroundScreening for abdominal aortic aneurysms (AAA) is currently recommended by several vascular societies. In countries where it has been introduced the prevalence of AAAs differed greatly and was mainly related to cigarette smoking. The screening program also had an enormous impact on the decrease of AAA ruptures and reduced mortality rate. These facts have led to the introduction of the first screening program for AAAs in Poland.ObjectiveThe aim of the study was to determine the prevalence of AAAs among men aged 60 years and older undergoing ultrasound examination of the abdominal aorta.Material and methodsA single ultrasonography of the abdomen was performed to assess the aorta from the renal arteries to the bifurcation and the diameter of the aorta was measured at its widest point. The cut-off value for determining an aortic aneurysm was set at a diameter of ≥ 30 mm. All ultrasonography measurements were performed by physicians in outpatient departments throughout the Kuyavian-Pomeranian Province. Additionally, each subject had to fill out a questionnaire with demographic data, smoking habits, existing comorbidities and familial occurrence of AAAs. The study was conducted from October 2009 to November 2011.ResultsThe abdominal aorta ultrasound examinations were carried out in 1556 men aged 60 years and older. The prevalence of AAA in the study population was 6.0 % (94 out of 1556). The average age of the men was 69 years (SD 6 years, range 60–92 years). In the study population 55 % of the men smoked or had smoked and 3 % were aware of the presence of AAAs in family members. There were three risk factors significantly associated with the presence of AAAs: age (p < 0.05), smoking (72.3 % vs 53.9 %, p = 0.004) and family history of AAAs (9.6 % vs 2.7 %, p = 0.017).ConclusionThe prevalence of AAAs among men in Poland is higher than in other European countries and the USA. The screening program for AAAs is an easy and reliable method for detecting early stages of the disease and risk factors which are the driving forces for the development of AAAs.

Abstract P340: Associations between Subclinical Carotid Atherosclerosis and Future Risk of Abdominal Aortic Aneurysm: the Atherosclerosis Risk in Community (ARIC) Study

Background: Abdominal aortic aneurysm (AAA) is a potentially lethal vasculopathy that shares multiple risk factors with conventional atherosclerotic disease, including advanced age, male sex, hypertension, and smoking. However, it is still debated whether subclinical atherosclerosis is an independent risk factor for AAA. Hypothesis: Subclinical carotid atherosclerosis is positively associated with future risk of AAA, independent of shared cardiovascular risk factors. Methods: We included 15,363 ARIC participants (74% whites) who had measures of carotid ultrasound at baseline (1987-89) at 45-64 years of age. Carotid intima-media thickness (cIMT) was measured bilaterally in the common carotid artery, carotid bifurcation, and internal carotid artery. Mean cIMT was estimated by combining the averages of cIMT measures at the 6 carotid sites. The presence of atherosclerotic plaque at any of the 6 segments was defined based on wall thickness ≥1.5 mm, or the presence of luminal encroachment or irregular intimal surface, or characteristics of arterial wall structural heterogeneity. Clinical AAAs were ascertained through hospital discharge diagnoses and death certificates through 2010. We used Cox proportional hazard models to examine the association between baseline carotid ultrasound measures and subsequent occurrence of clinical AAA. Results: In the total study sample (age 54±6 years, 45% men), the median (25 th to 75 th percentiles) cIMT at baseline was 0.71 (0.62 to 0.82) mm. Over an average of 21 years of follow up, a total of 392 clinical AAAs (74% male and 85% Whites) were ascertained. After adjustment for age, sex and race, participants in the highest quartile of baseline cIMT had 2.25 times higher risk of AAA (95% CI: 1.81, 2.79) compared to those in the lower 75 percentile. The presence of carotid atherosclerotic plaque at baseline was associated with 1.77 times increased risk of AAA (95% CI: 1.44, 2.17) after adjustment for age, sex and race. The associations for cIMT and atherosclerotic plaque remained significant after additional adjustment for baseline height, pack-years of smoking, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and hypertension: HR=1.66 (95% CI: 1.32, 2.08) for cIMT quartile 4 vs lower 75 percentile and 1.34 (95% CI: 1.08, 1.66) for presence of carotid atherosclerotic plaque. Further exclusion of participants with history of coronary heart disease or stroke at baseline slightly attenuated but did not abolish the associations of cIMT and atherosclerotic plaque with AAA (p&lt;0.05 after the exclusions). Conclusion: Our study findings suggest that subclinical carotid atherosclerosis in middle-age is independently associated with future risk of clinical AAA.

Polymorphisms of genes involved in the hypoxia signaling pathway and the development of abdominal aortic aneurysms or large-artery atherosclerosis

The pathogenesis of aortic diseases, both aneurysmal and occlusive, is associated with the occurrence of local ischemic/hypoxic conditions, but the genetic factors that differentiate the predisposition to specific types of aortic diseases are largely unknown. In this study, the functional variants in genes involved in the hypoxia signaling pathway, hypoxia-inducible factor-1α (HIF1A) 1772C>T, 1790G>A, and vascular endothelial growth factor (VEGFA) -634G>C, were analyzed in search of the associations specific to abdominal aortic aneurysm (AAA) development. The study encompassed a series of 518 patients with AAA, 354 patients with aortoiliac occlusive disease, and 541 controls. In AAA patients, the occurrence of peripheral arterial disease (PAD) was examined with duplex arterial scanning. Genotypes were determined by the polymerase chain reaction/restriction fragment length polymorphism method or with TaqMan probes. In univariate analysis, a significantly increased risk for development of AAA without coexisting PAD was found in VEGFA -634C allele carriers (effect of allele dose: odds ratio [OR], 1.38; P = .012). In VEGFA -634CC homozygotes, the risk was enhanced by the interaction with HIF1A 1772CC-1790GG genotype (OR, 2.41; P = .008). This joint effect of homozygous genotypes also influenced the AAA risk independently of PAD coexistence (OR, 1.87; P = .036). In contrast, the minor allele of the HIF1A 1772C>T polymorphism (1772T and 1772T-1790G haplotype) was significantly associated with the occurrence of AAA with concomitant PAD (OR, 2.02; P = .009 for the dominant model). This effect was enhanced in the VEGF -634GG homozygotes (OR, 2.86; P = .005) and among smokers (OR, 3.10; P = .001). The individual effects of the HIF1A 1772 and VEGFA -634 polymorphisms on AAA risk remained significant in multivariable analysis after adjustment for the traditional vascular risk factors and analyzed polymorphisms. None of the studied variants influenced the risk of aortoiliac occlusive disease. This study identifies polymorphisms in the HIF1A and VEGF genes as potential genetic markers that indicate the predisposition to either AAA coexisting with peripheral atherosclerosis or AAA without such lesions, suggesting the genetic heterogeneity of this disease. The HIF1A 1772T allele also seems to be a genetic risk factor that determines sensitivity to cigarette smoke exposure. Further work is needed to confirm the findings in an independent samples set and to study the functional role of studied variants in AAA.

The study of t-PA, u-PA and PAI-1 genes polymorphisms in patients with abdominal aortic aneurysm

The most important feature of abdominal aortic aneurysm (AAA) pathogenesis is an enzymatic degradation of elastic lamellae and extracellular matrix proteins particularly with participation of matrix metalloproteinases. Plasmin, which is responsible for the dissolution of fibrin in blood vessels, plays also a key role in the cascade for activation of the metalloproteinases. The purpose of this study was to evaluate the influence of selected polymorphisms in genes coding for tissue plasminogen activator (−7351 C/T polymorphism), urokinase-type plasminogen activator (1788 C/T polymorphism) and plasminogen activator inhibitor 1 (−675 4G/5G and −844 G/A polymorphism) on the susceptibility to AAA. We performed a case–control study of 153 polish patients hospitalized due to AAA and compared them with matched healthy control subjects. The polymorphisms were ascertained through genotyping by polymerase chain reaction and restriction digestion of amplified fragments or through high-resolution melting analysis. In this study we have found lower frequency of wild-type GG genotype of the −844G/A PAI-1 polymorphism in cases than in controls, what may suggest the protective effect of this genotype for the risk of AAA development. None of the remaining polymorphisms tested were associated with AAA occurrence.

Management of Synchronous Renal Cell Carcinoma and Abdominal Aortic Aneurysm as a Single Staged Operation

Simultaneous occurrence of abdominal aortic aneurysm and renal cell carcinoma is a rare entity. Benefits of single stage operations have to be weighed against staged operations. There is no consensus on the best management approach for patients with simultaneous aortic aneurysm and malignancy. Various possibilities have been considered, namely, to repair the aneurysm and treat the malignancy later, to resect the malignancy and repair the aneurysm later, to undertake both procedures simultaneously, and in some cases to treat the malignancy and manage the aneurysm conservatively. Aortic aneurysm repair is a prophylactic procedure and is worthwhile where the lifetime risk of rupture exceeds the risk from treatment. The prognosis of cancer is therefore central to the decision making process. The perceived increase risk of aortic aneurysm rupture following cancer surgery, the significant delay in the treatment of cancer if aneurysm is treated first, and the risk of graft infection are the other important considerations in the management of concomitant aortic aneurysm and cancer. In staged operations, malignancy or abdominal aortic aneurysm (AAA) first have to be decided depending on stage of cancer, risk of aneurysm rupture, graft infection and other comorbid features. We rarely encounter a situation where abdominal aortic aneurysm and abdominal malignancy, in particular renal cell carcinoma (RCC) occurs concomitantly and treated as single staged operation. Patient underwent bypass graft followed by partial nephrectomy through a midline laparotomy. Patient had uneventful post operative recovery except for chylous leak, not subsiding with conservative treatment followed by blockage of lymphatic fistula with computerized tomography (CT) guided fibrin glue application. Chylous ascites has to be treated as early as possible since it increases the possibility of graft infection. In this case, we discuss various possibility to approach a case of synchronous malignancy, and chylous ascites management through ‘CT guided fibrin glue application’ for a favourable outcome.

Curcumin Attenuates Angiotensin II-Induced Abdominal Aortic Aneurysm by Inhibition of Inflammatory Response and ERK Signaling Pathways.

Background and Objectives. Curcumin has long been used to treat age-related diseases, such as atherosclerosis and coronary heart disease. In this study, we explored the effects of curcumin on the development of abdominal aortic aneurysm (AAA). Methods. ApoE−/− mice were randomly divided into 3 groups: AngII group, AngII + curcumin (AngII + Cur) group (100 mg/kg/d), and the control group. Miniosmotic pumps were implanted subcutaneously in ApoE−/− mice to deliver AngII for 28 days. After 4-week treatment, abdominal aortas with AAA were obtained for H&E staining, immunohistochemistry, and Western blotting. Results. The results showed that curcumin treatment significantly decreased the occurrence of AAA. The levels of macrophage infiltration, monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factors-α (TNF-α) were significantly lower in AngII + Cur group than those in AngII group (all P < 0.01). The level of superoxide dismutase (SOD) was significantly higher in AngII + Cur group than those in AngII group (P < 0.01). The ERK1/2 phosphorylation in AngII + Cur group was significantly lower than that in AngII group (P < 0.01). Conclusions. These results suggested that curcumin can inhibit the AngII-induced AAA in ApoE−/− mice, whose mechanisms include the curcumin anti-inflammation, antioxidative stress, and downregulation of ERK signaling pathway.

Abstract 032: Associations between Middle-age Risk Factors and Future Risk of Abdominal Aortic Aneurysm: The Atherosclerosis Risk in Communities (ARIC) Study

Introduction: Abdominal aortic aneurysm (AAA) is an important manifestation of vascular disease in older age and rupture of an AAA is a life threatening condition. Traditional atherosclerotic disease risk factors, particularly male sex, smoking and hypertension, are known to contribute to the etiology of AAA. However, epidemiologic studies of AAA have often been cross-sectional, and few have employed a prospective cohort design, especially with long follow-up. The objective of this study was to prospectively assess the association between atherosclerotic disease risk factors and hospitalized AAA in 15,722 participants (68% whites) of the ARIC study, a large, community-based cohort. Methods: Risk factors were measured at baseline at 45-64 year of age. Clinical AAAs were ascertained through hospital discharge diagnoses or death certificates. Over 15 years of follow-up, a total of 265 AAAs (85.3% whites) were identified, including repair procedures, AAA rupture or dissection, and incidental detection. Multivariable Cox proportional hazard models were used to estimate the association of risk factors with the risk of future AAA. Results: Consistent with the literature from prospective studies, we identified age, male gender, white race, smoking, height, total and HDL cholesterols, triglycerides, white blood cell count, and hypertension as risk factors for AAA (Table). In addition, LDL-C, fibrinogen, and peripheral artery disease that were previously reported only in cross-sectional case-control studies were also strongly associated with AAA (Table). Body mass index, diabetes, and alcohol consumption were not associated with AAA occurrence. Conclusions: Several lifestyle and clinical variables measured in middle-age were strong risk factors for future AAA during a long follow-up.

Concomitant elective resection of pheochromocytoma and repair of aortic abdominal aneurysm

Perioperative management of a patient with ischemic heart disease with coexisting abdominal aortic aneurysm and pheochromocytoma creates a difficult management dilemma, and surgical intervention in these patients carries a significant risk. The state of catecholamine excess and various other coexisting factors can lead to simultaneous occurrence of abdominal aortic aneurysm and pheocromocytoma. The purpose of this report is to present an integrated approach to the management of concomitant abdominal aortic aneurysm and pheochromocytoma, where a combined surgical approach in addressing these two lesions was preferable due to patient comorbidities and surgical implications without significant complication.

Correlation of osteopontin and nuclear factor-κB expression with pathogenesis of abdominal aortic aneurysm in rats

Objective To establish rat model of abdominal aortic aneurysm (AAA),observe the expression of osteopontin (OPN) and nuclear factor-κB (NF-κB) and explore the molecular mechanism of AAA.Methods Thirty rats were divided into 3 groups (n =10 each).The rat AAA models were made by perfusing pancreatopeptidase E from hog pancreas into the aorta of rats for 30 min.Aortas were taken out two weeks after perfusion and the diameter of all aortas was measured.Hematoxylin and eosin (HE) staining was used to observe the structural change and elastase staining to observe how the area of elastase altered in the middle tuna of the aorta.Immunohistochemistry and Western blotting were used to detect the expression of OPN,NF-κB and matrix metalloproteinase-2 (MMP-2).Results Rat AAA model was successfully made.As compared with saline group and normal group,the infiltration of inflammatory cells was significantly increased and the quantity of elastase was significantly reduced in experimental group.Immunohistochemistry revealed that the expression of OPN was significantly increased in experimental group (P ＜ 0.05).Western blotting demonstrated that the expression of OPN was also obviously increased in experimental group (P ＜ 0.01).Conclusion OPN may increase the expression of MMP-2 through the NF-κB pathway in rat AAA model,thereby accelerating the degradation of extracellular matrix and eventually leading to occurrence of AAA. Key words: Abdominal aortic aneurysm; Osteopontin; Nuclear factor-κB; Matrix metallo-proteinase-2

Biomarkers for Abdominal Aortic Aneurysms From a Sex Perspective

Abdominal aortic aneurysms (AAAs) differ in men and women. Women are older at diagnosis, have a higher risk of rupture, and worse outcome after surgery compared with men. The higher occurrence of AAAs in men accounts for the dominance of men in biomarker analyses. The primary aim of this study was to investigate levels of established biomarkers for AAA in men and women, and the secondary aim was to compare biomarker levels in women with and without AAAs. In this prospective case-control study, blood samples were collected from 16 women and 18 men with AAAs ≥5.5 cm, from 20 women with AAAs <5.5 cm, and from 18 women with peripheral artery disease (PAD). Plasma concentrations of matrix metalloproteinase (MMP) -2, -9, and -13; tissue inhibitor of MMP-1 (TIMP-1); plasminogen activator inhibitor 1 (PAI-1); high-sensitivity C-reactive protein (hsCRP); and estradiol levels were analyzed by ELISA. An ultrasound examination was performed in women with PAD to exclude an AAA. Age and other comorbid conditions were similar between men and women with AAAs. Women with AAAs had higher levels of MMP-9 compared with men with equally large AAAs (42.8 ng/mL vs 36.2 ng/mL, P = 0.036) and lower levels of estradiol (30.0 pmoL vs 86.5 pmol/L, P < 0.001). Women with AAAs had lower levels of MMP-9 compared with women without (59.5 ng/mL vs 132.6 ng/mL, P = 0.010). There was no significant difference in the plasma levels of MMP-2, MMP-13, hsCRP, PAI-1, TIMP-1, and estradiol between women with and without AAAs. The higher levels of MMP-9 in women compared with men with equally large AAAs could suggest that MMP-9 is a biomarker related to the sex differences in aneurysm development. The lower levels of estradiol in women with AAAs compared with men suggest that the possible protective effect of endogenous estrogen cannot be explained by a difference in circulating levels of estradiol.

Association analysis of genetic polymorphisms of factor V, factor VII and fibrinogen β chain genes with human abdominal aortic aneurysm

Increased activity of the coagulation system is associated with the increased risk of many arterial thrombotic diseases and atherosclerosis. The purpose of this study was to evaluate the influence of selected polymorphisms in genes coding for coagulation factor V (1691 G/A, the so-called Leiden mutation), factor VII (−323 0/10 bp insertion/deletion) and fibrinogen β chain (−455 G/A) on the risk of abdominal aortic aneurysm, a particular form of atherothrombosis. We conducted a case-control study of 153 Polish patients hospitalized due to abdominal aortic aneurysm (AAA) and compared the results to those obtained from matched healthy control subjects. The polymorphisms were ascertained through genotyping by polymerase chain reaction and restriction digestion of amplified fragments. The study revealed that individuals carrying heterozygous genotype GA for the fibrinogen β chain −455 G/A mutation had at least a 2-fold greater likelihood of AAA development compared to control subjects (OR=3.01; 95% CI 1.83–4.96). The cases possessing homozygous mutant genotype (AA) had no significant risk of developing AAA compared to the control subjects (OR=1.12; 95% CI 0.33–2.44; p=0.83). Concerning factor V 1691 G/A and factor VII −323 0/10 bp mutations, we did not find any statistically significant correlation between them and AAA occurrence. In conclusion, we suggest that the −455G/A polymorphism of the fibrinogen β chain gene is a potential genetic marker to identify the risk of AAA.

Evaluation of a mobile screening service for abdominal aortic aneurysm in Broken Hill, a remote regional centre in far western NSW

To evaluate the feasibility of a mobile screening service model for abdominal aortic aneurysm (AAA) in a remote population centre in Australia. Screening test evaluation. A remote regional centre (population: 20 000) in far western NSW. Men aged 65-74 years, identified from the Australian Electoral roll. A mobile screening service using directed ultrasonography, a basic health check and post-screening consultation. Attendance at the screening program, occurrence of AAA in the target population and effectiveness of screening processes. A total of 516 men without a previous diagnosis of AAA were screened, an estimated response rate of 60%. Of these, 463 (89.7%) had a normal aortic diameter, 28 (5.4%) ectatic and 25 (4.9%) a small, moderate or significant aneurysm. Two men with AAA were recommended for surgery. Feedback from participants indicated that the use of a personalised letter of invitation helped with recruitment, that the screening process was acceptable and the service valued. It is feasible to organise and operate a mobile AAA screening service from moderate sized rural and remote population centres. This model could be scaled up to provide national coverage for rural and remote residents.

Concomitant rectal cancer and abdominal aortic aneurysm: a management strategy

The simultaneous occurrence of abdominal aortic aneurysm and rectal cancer is uncommon but represents a therapeutic dilemma. We report two patients in whom endovascular stenting of the aneurysm was not feasible. These patients were managed by an initial retroperitoneal aortic repair followed a few weeks later by an ultra low anterior resection.

Management of simultaneous abdominal aortic aneurysm and colorectal cancer: The rationale of mini-invasive approach

The concomitant occurrence of abdominal aortic aneurysm and malignancy represents a therapeutic dilemma. Both lesions should be treated to achieve best life expectancy; the main controversy remains whether to treat them simultaneously or as staged procedures. Recently, endovascular repair has been suggested as a potential alternative to open standard intervention. We present a case of synchronous abdominal aortic aneurysm and colorectal cancer treated simultaneously by minimally invasive surgery.

Priority of resection in concomitant abdominal aortic aneurysm (AAA) and colorectal cancer (CRC): review of the literature and experience of our clinic

The concomitant occurrence of abdominal aortic aneurysm (AAA) and colorectal cancer (CRC), although rare, always represents a therapeutic dilemma. The incidence of coexistence ranges between 0.49 and 2.1%. Both lesions should be treated to achieve best life expectancy. But the main controversy revolves around whether to treat them simultaneously or as staged procedures. In our institution, we treated seven cases of concomitant AAA and CRC. In five of them, synchronous conventional resection was preferred. In the latest two, which we present, endovascular aortic repair was chosen. No graft infection was documented.

Middle Age Cardiovascular Risk Factors and Abdominal Aortic Aneurysm in Older Age

Few prospective studies have examined associations between major cardiovascular risk factors and occurrence of abdominal aortic aneurysm; findings from cross-sectional studies are inconsistent. This long-term population-based study assessed relationships of major risk factors in middle-age to clinical nonfatal plus fatal abdominal aortic aneurysm in older-age in the Chicago Heart Association Detection Project in Industry cohort--10 574 men and 8700 women baseline ages 40 to 64 years screened for risk factors in 1967-1973 at workplaces. With average follow-up of 30 years and clinical cases identified from Medicare records and death certificates, risk factor relationships to abdominal aortic aneurysm occurrence were assessed by Cox regression. There were among men 309 cases and among women, 109--most from Medicare records. Most findings were qualitatively similar for men and women. In multivariate analyses (5 models), hazard ratios for abdominal aortic aneurysm were significantly greater for men than women (> or =1.97), with older age (> or =1.63/5 years), higher serum cholesterol (> or =1.30/40.0 mg/dL), cigarettes/d (> or =2.43/20 cigarettes), past smoking (> or =1.41), height (> or =1.17/7 cm), evidence of adverse blood pressure (hazard ratio 1.10/20 mm Hg higher systolic pressure, 1.12 to 1.14/12 mm Hg higher diastolic pressure, 1.87 with history of treated hypertension). It is concluded that major cardiovascular risk factors--serum cholesterol, smoking, and blood pressure--in middle age relate significantly to risk of abdominal aortic aneurysm in persons surviving into older age.

Epidemiology of abdominal aortic aneurysm in an Asian population.

Abdominal aortic aneurysms (AAA) are common in the Caucasian population. Apart from reported differences in the occurrence of AAA in the black and white populations, there are few studies on the incidence of AAA in the Asian population. A prospective database of all patients with AAA seen between 1996 and 1999, in the South-East Asian state of Sarawak in Borneo Island, was analysed. The demographic data included patient's age, sex, ethnic group, date of diagnosis, comorbidities, presentations and treatment outcomes. These were compared with the state population's demographic statistics. Diagnoses of AAA were made in 123 patients during the study period. The male to female ratio was 3.5 : 1. The age range was 39-88 years with a median age of 70 years. Four patients were younger than 55 years. The incidence rate for the at-risk male population older than 50 years was 25.6/100,000. The incidence rate reached 78.3/100,000 for males older than 70 years. The incidence rate for females older than 50 years was 7.6/100,000 and for those older than 70 years it was 18.7/100,000. All races were affected. Smoking, hypertension or respiratory disorders were present in more than 40% of the patients. Half of the patients underwent surgical repair. This study shows that AAA in this Asian population is not uncommon and the incidence is comparable to the Western world.

Familial abdominal aortic aneurysms: collection of 233 multiplex families.

This study investigated a large number of families in which at least two individuals were diagnosed with abdominal aortic aneurysms to identify the relationship of the affected relatives to the proband. Families for the study were recruited through various vascular surgery centers in the United States, Finland, Belgium, Canada, the Netherlands, Sweden, and the United Kingdom and through our patient recruitment website (www.genetics.wayne.edu/ags). We identified 233 families with at least two individuals diagnosed with abdominal aortic aneurysms. The families originated from nine different nationalities, but all were white. There were 653 aneurysm patients in these families, with an average of 2.8 cases per family. Most of the families were small, with only two affected individuals. There were, however, six families with six, three with seven, and one with eight affected individuals. Most of the probands (82%) and the affected relatives (77%) were male, and the most common relationship to the proband was brother. Most of the families (72%) appeared to show autosomal recessive inheritance pattern, whereas in 58 families (25%), abdominal aortic aneurysms were inherited in autosomal dominant manner, and in eight families, the familial aggregation could be explained by autosomal dominant inheritance with incomplete penetrance. In the 66 families where abdominal aortic aneurysms were inherited in a dominant manner, 141 transmissions of the disease from one generation to another were identified, and the male-to-male, male-to-female, female-to-male, and female-to-female transmissions occurred in 46%, 11%, 32%, and 11%, respectively. Our study supports previous studies about familial aggregation of abdominal aortic aneurysms and suggests that first-degree family members, male relatives, in particular, are at increased risk. No single inheritance mode could explain the occurrence of abdominal aortic aneurysms in the 233 families studied here, suggesting that abdominal aortic aneursyms are a multifactorial disorder with multiple genetic and environmental risk factors.