Prevalence of abdominal aortic aneurysms in men with diabetes

Rosmarinic Acid Suppresses Abdominal Aortic Aneurysm Progression in Apolipoprotein E-deficient Mice

An abdominal aortic aneurysm is a life-threatening cardiovascular disorder caused by dissection and rupture. No effective medicine is currently available for the > 90% of patients whose aneurysms are below the surgical threshold. The present study investigated the impact of rosmarinic acid, salvianolic acid C, or salvianolic acid B on experimental abdominal aortic aneurysms. Abdominal aortic aneurysms were induced in apolipoprotein E-deficient mice via infusion of angiotensin II for 4 wks. Rosmarinic acid, salvianolic acid C, salvianolic acid B, or doxycycline as a positive control was provided daily through intraperitoneal injection. Administration of rosmarinic acid was found to decrease the thickness of the aortic wall, as determined by histopathological assay. Rosmarinic acid also exhibited protection against elastin fragmentation in aortic media and down-regulated cell apoptosis and proliferation in the aortic adventitia. Infiltration of macrophages, T lymphocytes, and neutrophils in aortic aneurysms was found, especially at the aortic adventitia. Rosmarinic acid, salvianolic acid C, or salvianolic acid B inhibited the infiltration on macrophages specifically, but these compounds did not influence T lymphocytes and neutrophils. Expression of matrix metalloproteinase 9 and macrophage migration inhibitory factor significantly increased in aortic aneurysms. Rosmarinic acid and salvianolic acid C decreased the expression of matrix metalloproteinase-9 in media, and rosmarinic acid also tended to reduce migration inhibitory factor expression. Further then, partial least squares-discriminate analysis was used to classify metabolic changes among different treatments. Rosmarinic acid affected most of the metabolites in the biosynthesis of the citrate cycle, fatty acid pathway significantly. Our present study on mice demonstrated that rosmarinic acid inhibited multiple pathological processes, which were the key features important in abdominal aortic aneurysm formation. Further study on rosmarinic acid, the novel candidate for aneurysmal therapy, should be undertaken to determine its potential for clinical use.

The UK EndoVascular Aneurysm Repair (EVAR) randomised controlled trials: long-term follow-up and cost-effectiveness analysis

BACKGROUND

Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years.

OBJECTIVE

To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention.

DESIGN

Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2.

SETTING

Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004.

PARTICIPANTS

Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding.

INTERVENTIONS

EVAR, OR or no intervention.

MAIN OUTCOME MEASURES

The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness.

RESULTS

In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27; p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality; p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56, p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65, p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality.

LIMITATIONS

Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009.

CONCLUSIONS

EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign.

FUTURE WORK

To find easier ways to monitor sac expansion to trigger timely reintervention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN55703451.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full in Health Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.

Association between diabetes and prevalence and growth rate of abdominal aortic aneurysms: A meta-analysis

BACKGROUND

Although the prevalence of abdominal aortic aneurysm (AAA) was lower in diabetes, the relationship between diabetes and AAA prevalence remains unclear. In this meta-analysis, we sought to clarify the effect of diabetes on prevalence and growth rate (GR) of AAA.

METHODS

We searched PubMed, Web of Science, Scopus and Cochrane databases. Articles reporting the AAA prevalence in diabetic patients and diabetic effects in GR of AAA were included.

RESULTS

Forty-nine studies on AAA prevalence in diabetics and thirteen studies on effect of diabetes in GR of AAA were included for meta-analysis. A strongly negative association was found between diabetes and AAA prevalence in population based screening (odds ratio [OR]adjusted: 0.66; 95% confidence interval [CI]: 0.58-0.75) and prospective studies (ORadjusted: 0.52; 95% CI: 0.43-0.63), but not in case-control studies (ORadjusted: 0.48; 95% CI: 0.20-1.15). Similar association was found in North American (ORadjusted: 0.62; 95% CI 0.54-0.71) and European (ORadjusted: 0.45; 95% CI 0.33-0.62) studies. The strongly negative association remained consistent after stratification by time of data collection (up to -1995 [ORadjusted: 0.65; 95% CI: 0.53-0.80], 1996-2005 [ORadjusted: 0.61; 95% CI: 0.47-0.78], 2006 and beyond- [ORadjusted: 0.67; 95% CI: 0.53-0.85], and data collection time >10years [ORadjusted: OR: 0.44; 95% CI 0.34-0.58]). The annual mean diabetic effect on AAA GR was -0.60mm/y (95% CI: -0.76 - -0.43).

CONCLUSION

Diabetes was strongly and negatively associated with AAA prevalence regardless of study type, geography and time of data collection, as well as negative impact of diabetes on GR of AAA.

Abdominal aortic aneurysms--glycaemic status and mortality

AIMS

The prevalence of diabetes mellitus (DM) and mortality with respect to glycaemic status in patients with abdominal aortic aneurysms (AAA) was evaluated. Glycaemic status was assessed by an oral glucose tolerance test (OGTT) and by HbA1c.

METHODS

Sixty-six patients with AAA admitted to the vascular surgery unit for elective surgery between October 2006 and September 2007 were included. Seven patients had previously known DM. OGTT and HbA1c results were available from 58 patients. The patients were categorized as having DM, prediabetes and normoglycaemia according to the WHO's and American Diabetes Association's criteria.

RESULTS

The prevalence of newly diagnosed DM according to the OGTT and HbA1c results were 12% and 14% respectively. Mean follow-up time was 68 months and all-cause mortality 43%. HbA1c was an independent predictor for mortality in the DM category. Hazard ratio of all-cause mortality in the DM category defined by the HbA1c values was 6.35, 95% [CI 1.49-27.1]; p = 0.01.

CONCLUSIONS

DM defined by HbA1c ≥ 6.5% is an important determinant of mortality following surgical treatment for AAA. Half the patients with AAA and DM were unaware of their DM diagnosis. All patients with AAA should be tested for DM using HbA1c. The results should be confirmed in a larger prospective study.

Hyperglycemia limits experimental aortic aneurysm progression

OBJECTIVE

Diabetes mellitus (DM) is associated with reduced progression of abdominal aortic aneurysm (AAA) disease. Mechanisms responsible for this negative association remain unknown. We created AAAs in hyperglycemic mice to examine the influence of serum glucose concentration on experimental aneurysm progression.

METHODS

Aortic aneurysms were induced in hyperglycemic (DM) and normoglycemic models by using intra-aortic porcine pancreatic elastase (PPE) infusion in C57BL/6 mice or by systemic infusion of angiotensin II (ANG) in apolipoprotein E-deficient (ApoE(-/-)) mice, respectively. In an additional DM cohort, insulin therapy was initiated after aneurysm induction. Aneurysmal aortic enlargement progression was monitored with serial transabdominal ultrasound measurements. At sacrifice, AAA cellularity and proteolytic activity were evaluated by immunohistochemistry and substrate zymography, respectively. Influences of serum glucose levels on macrophage migration were examined in separate models of thioglycollate-induced murine peritonitis.

RESULTS

At 14 days after PPE infusion, AAA enlargement in hyperglycemic mice (serum glucose ≥ 300 mg/dL) was less than that in euglycemic mice (PPE-DM: 54% ± 19% vs PPE: 84% ± 24%, P < .0001). PPE-DM mice also demonstrated reduced aortic mural macrophage infiltration (145 ± 87 vs 253 ± 119 cells/cross-sectional area, P = .0325), elastolysis (% residual elastin: 20% ± 7% vs 12% ± 6%, P = .0209), and neovascularization (12 ± 8 vs 20 ± 6 vessels/high powered field, P = .0229) compared with PPE mice. Hyperglycemia limited AAA enlargement after ANG infusion in ApoE(-/-) mice (ANG-DM: 38% ± 12% vs ANG: 61% ± 37% at day 28). Peritoneal macrophage production was reduced in response to thioglycollate stimulation in hyperglycemic mice, with limited augmentation noted in response to vascular endothelial growth factor administration. Insulin therapy reduced serum glucose levels and was associated with AAA enlargement rates intermediate between euglycemic and hyperglycemic mice (PPE: 1.21 ± 0.14 mm vs PPE-DM: 1.00 ± 0.04 mm vs PPE-DM + insulin: 1.14 ± 0.05 mm).

CONCLUSIONS

Hyperglycemia reduces progression of experimental AAA disease; lowering of serum glucose levels with insulin treatment diminishes this protective effect. Identifying mechanisms of hyperglycemic aneurysm inhibition may accelerate development of novel clinical therapies for AAA disease.

Diabetes and the abdominal aortic aneurysm

OBJECTIVE

The aim of this review is to delineate the association between abdominal aortic aneurysms (AAAs) and diabetes mellitus. Mechanisms for the underlying association are then discussed.

METHODS

A systematic review of the English-language literature using PubMed, EMBASE and Cochrane databases was undertaken up to September 2009. Studies reporting appropriate prevalence data were identified and a meta-analysis performed.

RESULTS

Eleven studies were identified. The prevalence of diabetes mellitus in studied patients with AAA ranged from 6% to 14%. The prevalence of diabetes in control patients without AAA ranged from 17% to 36%. Pooled analysis suggested a reduced rate of diabetes amongst people with AAA compared to those without (OR 0.65, 0.60-0.70, p<0.001).

CONCLUSIONS

Studies so far suggest a protective role for diabetes on the development of AAA. Further research is required to demarcate the underlying mechanisms for this possible association.

Identifying abdominal aortic aneurysm risk factors in postmenopausal women

Evaluation of: Lederle FA, Larson JC, Margolis KL et al.: Abdominal aortic aneurysm events in the Women's Health Initiative: cohort study. Br. Med. J. 337, A1724 (2008). A linked cohort study of 161,808 postmenopausal women aged 50-79 years enrolled in the Women's Health Initiative was conducted during which participants were followed for the incidence of abdominal aortic aneurysm repair or rupture. This study evaluated the association between potential risk factors and subsequent abdominal aortic aneurysm events in women. A total of 467 women reported a diagnosis of abdominal aortic aneurysm before entering the study or during participation, with 184 aneurysm-related events identified. Abdominal aortic aneurysm events were strongly associated with age and smoking and negatively associated with diabetes and baseline use of postmenopausal hormone supplementation. Previous studies investigating abdominal aortic aneurysm have focused primarily on men, with little reliable information available on women. This study contributes a large female cohort to provide better insight into gender-specific abdominal aortic aneurysm risks and disease associations.

Negative Association between Infra-renal Aortic Diameter and Glycaemia: The Health In Men Study

OBJECTIVE

There is evidence of a negative association between diabetes and abdominal aortic aneurysm (AAA). The aim of this study was to assess whether there is a similar relationship between both diabetes and glucose level, and infra-renal aortic diameter throughout its range.

DESIGN AND METHODS

Infra-renal aortic diameter was measured using ultrasound in 12,203 men aged 65-83 years as part of a trial of screening for AAA. A range of cardiovascular risk factors were also assessed. In a follow-up study, fasting serum glucose was measured in 2,859 non-diabetic men. Aortic diameter was logarithmically transformed and treated as both a continuous and categorical variable in stepwise multivariate linear and logistic models.

RESULTS

The median aortic diameter was slightly smaller in the diabetic men (21.3+/-3.9 vs 21.6+/-3.8, P<0.0001). There was an independent negative association between diabetes and AAA (OR 0.79, 95% CI: 0.63,0.98), and an inverse correlation (Coefficient: -0.0064, p=0.0024) between fasting glucose and aortic diameter in non-diabetic men.

CONCLUSIONS

Diabetes is inversely associated with both AAA and aortic diameter in men over 65 years. This association is independent of other risk factors for AAA. Aortic diameter also has an inverse relationship with fasting glucose concentrations in men without diabetes.

Review of prevalence and outcome of vascular disease in patients with diabetes mellitus

OBJECTIVES

Review the literature to determine the prevalence and outcome in patients with diabetes that undergo surgery to correct carotid artery stenosis, lower extremity arterial disease, and abdominal aortic aneurysm (AAA).

DESIGN AND MATERIALS

Studies were obtained from searches over the past 15 years on the National Library of Medicine's online search engine.

RESULTS

The review demonstrated an equivalent prevalence of carotid artery stenosis requiring surgery in patients with diabetes, it favored no increase risk of post-CEA stroke, and it was split on perioperative morbidity and mortality risk. There was an increase prevalence of lower extremity arterial disease requiring surgery in patients with diabetes, it favored equivalent patency and limb salvage rates, and it was split on the morbidity and mortality risk. The review demonstrated a decrease in AAA prevalence among patients with diabetes, it found an increase in the morbidity risk, and equivalent mortality risk.

CONCLUSIONS

Stroke, graft patency, and limb salvage rates in patients with diabetes after surgery are similar to patients without diabetes; however, their risk of complications is increased after surgery and the mortality risk may be higher after CEA.

Varicose veins are common in patients with coronary artery ectasia. Just a coincidence or a systemic deficit of the vascular wall?

OBJECTIVES

Coronary artery ectasia (CAE), an uncommon finding during coronary arteriography, has been associated with the presence of aneurysm(s) in other parts of the arterial tree including the abdominal aorta. Varicose veins (VV) or phlebectasias are a common disorder of the superficial leg veins. Correlations between arterial and venous ectasias have not been established. We sought to examine whether there is an association between CAE and VV.

METHODS AND RESULTS

CAE was diagnosed in 181 patients out of 7510 eligible patients undergoing coronary arteriography within 33 months. The prevalence of VV was significantly higher among patients with CAE (40%) compared to 200 aged-matched patients with coronary artery disease but without CAE (17%) and to 201 randomly selected subjects from the general population (23%). In multivariate analysis, CAE was found to be significantly and independently associated with VV (RR=3.42, 95% confidence interval (CI) 2.24-5.59, p<0.001).

CONCLUSION

In this study population, VV were more common in patients with CAE than in those without. This association was valid in both univariate and multivariate analysis, suggesting the possible existence of a generalised defect of the entire vascular wall.

Relation of coronary artery ectasia to diabetes mellitus

An increased prevalence of coronary artery ectasia (CAE) and a low frequency of diabetes mellitus have been reported in patients with abdominal aortic aneurysm (AAA). The prevalence of diabetes was studied in 190 patients with CAE in comparison with 341 age- and gender-matched patients with coronary artery disease alone. Diabetes mellitus was found to be independently but inversely associated with CAE (relative risk 0.603, 95% confidence interval 0.375 to 0.960, p = 0.037), thus resembling the relation between diabetes and AAA.

Accuracy of abdominal examination in the diagnosis of non-ruptured abdominal aortic aneurysm

BACKGROUND

Early detection of abdominal aortic aneurysms (AAA) is paramount to reducing the very high mortality rates associated with rupture. This literature review was undertaken to assess the accuracy of abdominal examination in the detection of non-ruptured AAA.

METHOD

A comprehensive literature search was performed to retrieve prospective studies comparing the accuracy of physical examination (PE) in the diagnosis of non-ruptured AAA confirmed by the gold standard, ultrasonography.

RESULTS

The sensitivity of PE in the diagnosis of AAA ranges from 33% to 100%, the specificity from 75% to 100%, and the positive predictive value from 14% to 100%. Detection rates increase with increasing aortic diameter, increasing age, male sex, presence of recognisable risk factors, examination by an experienced clinician, PE directed specifically towards the detection of AAA, prevalence of AAA in study population, and thin patients.

CONCLUSION

Clinical examination cannot be relied upon to exclude AAA. Larger aneurysms are usually palpable and more likely to be detected on examination especially in thin patients. Due to the poor sensitivity of PE together with the high sensitivity and specificity of ultrasound, obese patients in whom there is difficulty palpating an aneurysm, despite a history suggestive of possible non-ruptured AAA, should be referred for ultrasound examination to assist with the diagnosis.

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.

[Screening of the abdominal aortic aneurysms during an echocardiography]

We examined the abdominal aorta by ultrasound in 1106 patients during transthoracic echocardiography, whatever the reason of the echocardiography, to track abdominal aortic aneurysms. The study group comprised 822 men and 284 women. We found 88 patients having an abdominal aorta with a diameter of more than 23 mm and 11 patients with a diameter of more than 35 mm. Ninety sixteen per cent of the patients having an aortic ecstasy are more than fifty years old. Ther are more smokers among the patients having an aortic ecstasy. In conclusion, the track of the ecstasies and the abdominal aortic aneurysms is easily realizable during an echocardiography and presents a good rentability.

Does the Mediterranean paradox extend to abdominal aortic aneurysm?

BACKGROUND

We sought to test, in men undergoing ultrasound screening for abdominal aortic aneurysms (AAA) in Western Australia, clinical impressions that the prevalence of AAA is high in Dutch migrants and low in migrants from Mediterranean countries.

METHODS

In a population-based trial, men undergoing screening for AAA completed a questionnaire covering their place of birth, smoking habits and consumption of alcohol, meat, fish, salt and milk. We examined the variation by place of birth in the mean, median, 95th and 99th centiles of infrarenal aortic diameter and the prevalences of AAA defined by criteria of 30 mm, 50 mm and by the 95th and 99th centiles, in men born in Australia, of aortic diameter adjusted for height.

FINDINGS

Overall, 12,203 (70.5%) of the 19 583 men took up the invitation to undergo ultrasound screening. The prevalence of AAA defined by absolute diameter was higher than average in men born in The Netherlands or Scotland (more of whom had ever smoked or smoked currently) and lower in men of Mediterranean origin (more of whom drank alcohol currently). There were no consistent relationships with simple dietary data. Correction of aortic diameter for height eliminated the significant heterogeneity in prevalence of large AAA, although a threefold variation in prevalence of AAA exceeding the 95th centile of height-adjusted diameter in Australian men persisted.

INTERPRETATION

In our cohort of men, which is subject to both 'healthy migrant' and 'survivor' effects, if it exists at all, any 'Mediterranean paradox' for AAA is more modest than that for coronary disease.

Screening for abdominal aortic aneurysm: lessons from a population-based study

OBJECTIVES

To test the acceptability of screening and to identify modifiable risk factors for abdominal aortic aneurysm (AAA) in men.

DESIGN

A trial of ultrasound screening for AAA in a population-based random sample of men aged 65-83 years, and a cross-sectional case-control comparison of men in the same sample.

PARTICIPANTS

12,203 men who had an ultrasound examination of their abdominal aorta, and completed a questionnaire covering demographic, behavioural and medical factors.

MAIN OUTCOME MEASURES

Prevalence of AAA, and independent associations of AAA with demographic, medical and lifestyle factors.

RESULTS

Invitations to screening produced a corrected response of 70.5%. The prevalence of AAAs (> 30 mm) rose from 4.8% in men aged 65-69 years to 10.8% in those aged 80-83 years. The overall prevalence of large (> 50 mm) aneurysms was 0.69%. In a multivariate logistic model Mediterranean-born men had a 40% lower risk of AAA (> 30 mm) compared with men born in Australia (odds ratio [OR], 0.6; 95% CI, 0.4-0.8), while ex-smokers had a significantly increased risk of AAA (OR, 2.3; 95% CI, 1.9-2.8), and current smokers had even higher risks. AAA was significantly associated with established coronary and peripheral arterial disease and a waist:hip ratio greater than 0.9; men who regularly undertook vigorous exercise had a lower risk (OR, 0.8; 95% CI, 0.7-1.0).

CONCLUSION

Ultrasound screening for AAA is acceptable to men in the likely target population. AAA shares some but not all of the risk factors for occlusive vascular disease, but the scope for primary prevention of AAA in later life is limited.

Association of the 4G/5G polymorphism in the promoter region of plasminogen activator inhibitor-1 with abdominal aortic aneurysms

PURPOSE

A familial component has previously been identified in 11% to 20% of patients with abdominal aortic aneurysms (AAAs). The genetic basis of familial AAA remains elusive, however. Matrix metalloproteinases have been implicated in aneurysm development; and plasmin, a serine protease, activates metalloproteinases. Plasminogen activator inhibitor-1 (PAI-1) regulates plasmin activation through the tissue plasminogen activators. A polymorphism within the promoter area of PAI-1 has been described that modifies PAI-1 expression and consequently plasminogen activation. The 4G homozygous variant is associated with increased PAI-1 expression and consequently reduced plasmin activity and therefore may be selected against in-familial AAA. The purpose of this study was to investigate the incidence of the 4G/5G insertion/deletion polymorphism in the promoter area of the PAI-1 gene in a population with AAA.

METHODS

Patients seen at a tertiary referral center for repair of abdominal aortic aneurysms were recruited. DNA was extracted from blood. Primers were designed to amplify a 99 (5G)-base pair (bp) and a 98 (4G)-bp fragment bracketing the polymorphism. The 5' primer was mutated to allow a restriction endonuclease to cleave the 5G polymorphism into a 77-bp and a 22-bp fragment. Samples were run on agarose gels and stained with ethidium bromide.

RESULTS

One hundred ninety patients with AAAs, including 39 patients with strong family histories and 163 controls were examined. The frequency of the 4G:5G alleles in the AAA population and in the control population was 0.6:0.4. However, 26% of patients with familial AAA were homozygous 5G compared with 13% of the control population. The 4G-allele frequency was 0.47 in the familial AAAs, compared with 0.62 in the nonfamilial patients (P =.02) and 0.61 in the control population (P =.03).

CONCLUSION

The selection against the 4G4G genotype in the familial AAA population may indicate a role for PAI in the development of AAA in this population.