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1.
Br J Surg ; 104(11): 1486-1493, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28650557

ABSTRACT

BACKGROUND: It has been suggested that diabetes medications, such as metformin, may have effects that inhibit abdominal aortic aneurysm (AAA) growth. The aim of this study was to examine the association of diabetes treatments with AAA growth in three patient cohorts. METHODS: AAA growth was studied using ultrasound surveillance in cohort 1, repeated CT in cohort 2 and more detailed repeat CT in cohort 3. Growth was estimated by the mean annual increase in maximum AAA diameter. RESULTS: A total of 1697 patients with an AAA were studied, of whom 118, 39 and 16 patients were prescribed metformin for the treatment of diabetes in cohorts 1, 2 and 3 respectively. Prescription of metformin was associated with a reduced likelihood of median or greater AAA growth in all three cohorts (cohort 1: adjusted odds ratio (OR) 0·59, 95 per cent c.i. 0·39 to 0·87, P = 0·008; cohort 2: adjusted OR 0·38, 0·18 to 0·80, P = 0·011; cohort 3: adjusted OR 0·13, 0·03 to 0·61, P = 0·010). No other diabetes treatment was significantly associated with AAA growth in any cohort. CONCLUSION: These findings suggest a potential role for metformin in limiting AAA growth.


Subject(s)
Aortic Aneurysm, Abdominal/diagnostic imaging , Hypoglycemic Agents/therapeutic use , Metformin/therapeutic use , Aged , Cohort Studies , Diabetes Mellitus/drug therapy , Female , Humans , Logistic Models , Male
2.
Diabet Med ; 34(6): 786-793, 2017 06.
Article in English | MEDLINE | ID: mdl-27761946

ABSTRACT

AIMS: To investigate behavioural, physical and biochemical characteristics associated with diabetes in the oldest age group of elderly men. METHODS: We conducted a cross-sectional analysis of community-dwelling men aged 79-97 years from Perth, Western Australia. Lifestyle behaviours, self-rated health, physical function, and fasting glucose and HbA1c levels were assessed. RESULTS: Of 1426 men, 315 had diabetes (22%). Men with diabetes were of similar age to men without (84.9 vs 84.5 years; P = 0.14). Only 26.5% of men with diabetes self-rated their health as excellent or very good, compared with 40.6% of men without diabetes (P < 0.001). Diabetes was associated with less involvement with recreational walking (32.7 vs 41.0%; P < 0.01) and leisure activities (19.0 vs 26.5%; P < 0.01). Men with diabetes had poorer physical function on multiple measures, including longer times for the Timed Up-and-Go test (15.0 ± 6.9 s vs 13.4 ± 5.3 s; P < 0.001) and weaker knee extension (20.2 vs 21.9 kg; P < 0.001). In multivariate analyses, diabetes was associated with an increased prevalence of myocardial infarction (odds ratio 1.80, 95% CI 1.25-2.60; P < 0.001) and falls resulting in injury (odds ratio 1.55, 95% CI 1.06-2.26; P = 0.02). Average HbA1c was 49 ± 8 mmol/mol (6.6 ± 0.8%) in men with diabetes, with 90.6% of these men on diet or oral hypoglycaemic therapy. CONCLUSIONS: In older men, diabetes is associated with poorer self-perceived health, reduced healthy lifestyle behaviours and physical function, heart disease and injurious falls. The majority of these men with diabetes had good glycaemic control. Encouraging healthy lifestyle behaviours and improving physical function should be evaluated as interventions to improve quality-of-life and health outcomes.


Subject(s)
Diabetes Mellitus/epidemiology , Health Status , Aged , Aged, 80 and over , Cross-Sectional Studies , Humans , Life Style , Male , Men's Health/statistics & numerical data , Quality of Life , Surveys and Questionnaires , Western Australia/epidemiology
3.
J Nutr Health Aging ; 19(8): 805-11, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26412284

ABSTRACT

BACKGROUND: The effect of dietary salt intake on important population outcomes such as mortality is controversial. The aim of this study was to examine the association between the dietary habit of adding salt to food and mortality in older men. Design, participants, setting and measurements: A risk factor questionnaire which contained a question about the dietary habit of adding salt to food was completed by 11742 community recruited older men between 1996 and 1999. The men were followed by means of the Western Australia Data Linkage System until November 30th 2010. Deaths due to cardiovascular diseases and cancers were identified using ICD-10 codes in the ranges I00-I99 and C00-D48, respectively. The association between the frequencies of adding salt to food and mortality was assessed using Kaplan Meier estimates and Cox proportional hazard analysis. RESULTS: Median follow-up for survivors was 12.5 years (inter-quartile range 8.3-13.2 years). A total of 5399 deaths occurred of which the primary cause registered was cancer and cardiovascular disease in 1962 (36.3%) and 1835 (34.0%) men, respectively. The reported frequency of adding salt to food was strongly positively associated with all-cause (p<0.001), cancer-related (p<0.001) but not cardiovascular-related (p=0.649) mortality. Men reporting adding salt to their food always had a 1.12-fold (95% CI 1.05-1.20, p<0.001) and a 1.20-fold (95% CI 1.07-1.34, p=0.001) increased risk of all-cause and cancer-related mortality, respectively, after adjusting for other risk factors. Men reporting adding salt to their food sometimes had a 1.16-fold (95% CI 1.04-1.29, p=0.007) increased risk of cancer-related mortality after adjusting for other risk factors. CONCLUSION: A history of adding salt to food is associated with increased cancer-related mortality in older men.


Subject(s)
Feeding Behavior , Neoplasms/mortality , Sodium Chloride, Dietary/adverse effects , Aged , Aged, 80 and over , Cardiovascular Diseases/mortality , Cause of Death , Cohort Studies , Food , Humans , Kaplan-Meier Estimate , Life Style , Male , Prospective Studies , Risk , Risk Factors , Surveys and Questionnaires , Western Australia/epidemiology
4.
Eur J Vasc Endovasc Surg ; 50(4): 466-73, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26188720

ABSTRACT

OBJECTIVE/BACKGROUND: Recent genetic data suggest that a polymorphism of LRP1 is an independent risk factor for abdominal aortic aneurysm (AAA). The aims of this study were to assess whether plasma and aortic concentrations of low-density lipoprotein receptor-related protein 1 (LRP1) are associated with AAA, and to investigate the possible relevance of LRP1 to AAA pathophysiology. METHODS: Three analyses were conducted. First, plasma LRP1 concentrations were measured in community-dwelling men with and without AAA (n = 189 and n = 309, respectively) using enzyme-linked immunosorbent assay. Second, Western blotting analyses were employed to compare the expression of LRP1 protein in aortic biopsies collected from patients with AAA and nonaneurysmal postmortem donors (n = 6/group). Finally, the effect of in vitro LRP1 blockade on matrix metalloprotease 9 (MMP9) clearance by vascular smooth muscle cells was assessed by zymography. RESULTS: Plasma LRP1 concentrations did not differ between groups of men with and without AAA (median concentration 4.56 µg/mL [interquartile range {IQR} (3.39-5.96)] and 4.43 µg/mL [IQR 3.44-5.84], respectively; p = .48), and were not associated with AAA after adjusting for other risk factors (odds ratio 1.10 [95% confidence interval: 0.91-1.32]; p = 0.35). In contrast, LRP1 expression was approximately 3.4-fold lower in aortic biopsies recovered from patients with AAA compared with controls (median [IQR] expression 1.72 [0.94-3.14] and 5.91 [4.63-6.94] relative density units, respectively; p < .01). In vitro LRP1 blockade significantly reduced the ability of vascular smooth muscle cells to internalize extracellular MMP9. CONCLUSIONS: These data suggest that aortic but not circulating LRP1 is downregulated in patients with AAA and indicates a possible role for this protein in clearing an aneurysm-relevant ligand.


Subject(s)
Aorta, Abdominal/metabolism , Aortic Aneurysm, Abdominal/blood , Low Density Lipoprotein Receptor-Related Protein-1/blood , Aged , Antibodies/pharmacology , Aorta, Abdominal/drug effects , Aortic Aneurysm, Abdominal/diagnosis , Biomarkers/blood , Biopsy , Blotting, Western , Case-Control Studies , Cells, Cultured , Down-Regulation , Enzyme-Linked Immunosorbent Assay , Humans , Low Density Lipoprotein Receptor-Related Protein-1/antagonists & inhibitors , Male , Matrix Metalloproteinase 9/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Odds Ratio , Risk Factors
5.
Circ Res ; 114(2): 379-93, 2014 Jan 17.
Article in English | MEDLINE | ID: mdl-24436433

ABSTRACT

Vitamin D plays a classical hormonal role in skeletal health by regulating calcium and phosphorus metabolism. Vitamin D metabolites also have physiological functions in nonskeletal tissues, where local synthesis influences regulatory pathways via paracrine and autocrine mechanisms. The active metabolite of vitamin D, 1α,25-dihydroxyvitamin D, binds to the vitamin D receptor that regulates numerous genes involved in fundamental processes of potential relevance to cardiovascular disease, including cell proliferation and differentiation, apoptosis, oxidative stress, membrane transport, matrix homeostasis, and cell adhesion. Vitamin D receptors have been found in all the major cardiovascular cell types including cardiomyocytes, arterial wall cells, and immune cells. Experimental studies have established a role for vitamin D metabolites in pathways that are integral to cardiovascular function and disease, including inflammation, thrombosis, and the renin-angiotensin system. Clinical studies have generally demonstrated an independent association between vitamin D deficiency and various manifestations of degenerative cardiovascular disease including vascular calcification. However, the role of vitamin D supplementation in the management of cardiovascular disease remains to be established. This review summarizes the clinical studies showing associations between vitamin D status and cardiovascular disease and the experimental studies that explore the mechanistic basis for these associations.


Subject(s)
Cardiovascular Diseases/metabolism , Cardiovascular System/metabolism , Vitamin D/metabolism , Animals , Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/physiopathology , Cardiovascular System/physiopathology , Dietary Supplements , Humans , Receptors, Calcitriol/metabolism , Signal Transduction , Vitamin D/therapeutic use , Vitamin D Deficiency/drug therapy , Vitamin D Deficiency/metabolism , Vitamin D Deficiency/physiopathology
6.
Eur J Vasc Endovasc Surg ; 45(6): 657-64, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23602862

ABSTRACT

OBJECTIVE: This study aims to investigate the association between plasma 25-hydroxyvitamin D (25(OH)D) concentrations with the presence of abdominal aortic aneurysm (AAA) and aortic diameter. DESIGN: An observational study of 4233 community-dwelling men aged 70-88 years, who participated in a randomised controlled trial of screening for AAA. METHODS: Infrarenal aortic diameter measured by ultrasound and 25(OH)D by immunoassay. RESULTS: A total of 311 men (7.4%) with AAA (defined as aortic diameter ≥ 30 mm) comprised the study. Multivariable models were adjusted for age, smoking, cardiovascular disease, hypertension, diabetes, dyslipidaemia, body mass index and serum creatinine concentration. Amongst men with the lowest 25(OH)D quartile of values compared with the highest quartile, the adjusted odds ratio of having an AAA increased in a graded fashion from 1.23 (95% confidence interval (CI) 0.87-1.73) for AAA ≥ 30 mm to 5.42 (95% CI 1.85-15.88) for AAA ≥ 40 mm. Similarly, there was a dose-response relationship between 25(OH)D concentrations and the size of the AAA: every 10-nmol l(-1) decrease in 25(OH)D levels was associated with 0.49 mm (95% CI 0.11-0.87) increase in mean aortic diameter. CONCLUSIONS: Low vitamin D status is associated with the presence of larger AAA in older men, and there is a graded inverse relationship between 25(OH)D concentrations and AAA diameter. Further research is needed to clarify the mechanisms underlying these associations.


Subject(s)
Aortic Aneurysm, Abdominal/epidemiology , Vitamin D Deficiency/epidemiology , Vitamin D/analogs & derivatives , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/diagnostic imaging , Biomarkers/blood , Comorbidity , Cross-Sectional Studies , Humans , Immunoassay , Logistic Models , Male , Multivariate Analysis , Odds Ratio , Predictive Value of Tests , Proportional Hazards Models , Risk Assessment , Risk Factors , Ultrasonography , Vitamin D/blood , Vitamin D Deficiency/blood , Western Australia/epidemiology
7.
Osteoporos Int ; 24(5): 1683-8, 2013 May.
Article in English | MEDLINE | ID: mdl-23160917

ABSTRACT

UNLABELLED: The aim of the present study was to assess whether peripheral arterial disease is associated with an increased risk of hip fracture in a cohort of 12,094 older men. There was no association between claudication and hip fracture, but there was a significant association with an ankle brachial index (ABI) <0.9. INTRODUCTION: It is uncertain whether peripheral arterial disease (PAD) is associated with an increased risk of subsequent hip fracture. The aim of the present study was to assess this in a large cohort of men aged 65 years and over. METHODS: Claudication was assessed by means of the Edinburgh Claudication Questionnaire in 12,094 men, and the ABI was measured in 4,321 of these men. Hospitalisations with hip fracture were identified by record linkage. The association between both claudication and an ABI <0.9 and subsequent hip fractures was assessed using survival curves and Cox regression models. RESULTS: Amongst the 12,094 men, the baseline prevalence of claudication according to the ECQ was 5.3 %. Amongst the 4,321 men with ABI results, the prevalence of an ABI <0.9 was 11.7 %. Of the 506 men with an ABI <0.9, 129 (25.5 %) also had claudication. Over a median (range) follow-up of 10.8 (0.3-12.7) years, 343 (2.8 %) of the 12,094 men were admitted to hospital with a hip fracture. There was no association between claudication and subsequent hip fractures (hazard ratio (HR) = 0.95; 95 % confidence interval (CI), 0.60, 1.52). Over a median (range) follow-up of 11.1 (0.06-12.3) years 135 (3.1 %) of the 4,321 men with ABI data were admitted to hospital with hip fractures. There was a significant association between an ABI <0.9 and subsequent hip fracture (HR = 1.69; 95 % CI, 1.08, 2.63). CONCLUSION: Older men with PAD defined as ABI < 0.9 are at increased risk of hip fracture, whereas the symptom of claudication is not an independent predictor of hip fracture.


Subject(s)
Hip Fractures/etiology , Peripheral Arterial Disease/complications , Aged , Ankle Brachial Index , Hip Fractures/epidemiology , Humans , Intermittent Claudication/complications , Intermittent Claudication/epidemiology , Kaplan-Meier Estimate , Male , Peripheral Arterial Disease/epidemiology , Prevalence , Risk Factors , Western Australia/epidemiology
8.
Osteoporos Int ; 23(2): 599-606, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21359669

ABSTRACT

SUMMARY: In older men, both lower and higher total osteocalcin levels predict increased all-cause mortality, with comparable associations for cardiovascular and non-cardiovascular deaths. Differences in osteocalcin levels might influence glucose metabolism and thereby cardiovascular risk, or reflect changes in bone turnover thus representing a marker for poorer health outcomes. INTRODUCTION: Reduced levels of total osteocalcin (TOC) are associated with adiposity, insulin resistance and type 2 diabetes, implying this bone-derived peptide might modulate cardiovascular risk. However, there are few longitudinal data relating TOC levels to survival. We examined associations of TOC level with all-cause and cardiovascular mortality in older men. METHODS: We conducted a prospective cohort study of community-dwelling men aged 70-89 years. Aliquots of plasma collected at baseline (2001-2004) were assayed for TOC. Incidence and causes of death to 31 December 2008 were ascertained using data linkage. Cox regression analyses were performed with adjustment for conventional cardiovascular risk factors. RESULTS: From 3,542 men followed for median 5.2 years there were 572 deaths (16.1%). Mortality was lowest in men with TOC levels in the second quintile (12.6%). In multivariate analyses, men with TOC in the lowest and highest quintiles of values had increased all-cause mortality (Q1 vs Q2: hazard ratio [HR], 1.36; 95% confidence interval 1.02-1.80 and Q5 vs Q2: HR, 1.53, 95% CI 1.18-1.98). Men with low TOC levels had similar HR for cardiovascular and non-cardiovascular deaths (Q1 vs Q2: HR, 1.35 and 1.30 respectively). Higher TOC levels predicted cardiovascular disease (CVD)-related mortality (Q5 vs Q2, HR, 1.69, 95% CI 1.09-2.64). CONCLUSIONS: TOC predicts all-cause and CVD-related mortality in community-dwelling older men. However, the relationship is U shaped with men at both ends of the distribution at increased risk. Further investigation is required to clarify whether the underlying mechanisms involve altered bone turnover or relate specifically to the biological activity of osteocalcin.


Subject(s)
Cardiovascular Diseases/blood , Mortality , Osteocalcin/blood , Aged , Aged, 80 and over , Anthropometry/methods , Biomarkers/blood , Cardiovascular Diseases/etiology , Cardiovascular Diseases/mortality , Epidemiologic Methods , Humans , Male , Western Australia/epidemiology
9.
Article in English | MEDLINE | ID: mdl-23835734

ABSTRACT

There is considerable interindividual variability in the growth of abdominal aortic aneurysms (AAAs), but an individual's growth observations, risk factors, and biomarkers could potentially be used to tailor surveillance. To assess the potential for tailoring surveillance, this study determined the accuracy of individualized predictions of AAA size at the next surveillance observation. A hierarchical Bayesian model was fitted to a total of 1,732 serial ultrasound measurements from 299 men in whom ultrasound screening identified an AAA. The data were best described by a nonlinear model with a constant first derivative of the AAA growth rate with size. The area under the receiver operating characteristic (ROC) curves for predicting whether an AAA was ≥40 or ≥50 mm at the next observation were 0.922 and 0.979, respectively, and the median root mean squared error was 2.52 mm. These values were nearly identical for models with or without plasma D-dimer effects.CPT: Pharmacometrics & Systems Pharmacology (2012) 1, e12; doi:10.1038/psp.2012.13; advance online publication 24 October 2012.

10.
Br J Surg ; 98(5): 619-22, 2011 May.
Article in English | MEDLINE | ID: mdl-21374589

ABSTRACT

BACKGROUND: The aim of this study was to compare the mortality rate within 30 days of elective surgery for abdominal aortic aneurysm (AAA) in men randomized to an invitation for ultrasound screening with that of men in the control group, whose aneurysms were detected incidentally. METHODS: Relevant reports from randomized trials of screening were identified through a systematic search of MEDLINE. Four relevant trials were identified, and supplemented with data from the Viborg Vascular screening trial. Data were updated in two studies. Meta-analysis was undertaken with effects calculated as a fixed odds ratio (OR) with 95 per cent confidence interval. Heterogeneity between the studies was assessed by the χ(2) test. RESULTS: There were 25 deaths (2·9 per cent) following elective surgery in 858 men invited for screening compared with 21 (5·5 per cent) of 383 in the control group (OR 0·49, 0·27 to 0·88). There were 18 deaths (2·4 per cent) following elective surgery for 747 screen-detected AAAs compared with 28 (6·1 per cent) following elective repair of 459 incidentally detected aneurysms (OR 0·37, 0·20 to 0·68). CONCLUSION: The offer of screening identifies men whose early survival following elective AAA repair is better than that of men with an AAA detected incidentally.


Subject(s)
Aortic Aneurysm, Abdominal/surgery , Elective Surgical Procedures/mortality , Age Distribution , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Aneurysm, Abdominal/mortality , Early Diagnosis , Female , Humans , Incidental Findings , Male , Middle Aged , Odds Ratio , Postoperative Complications/mortality , Randomized Controlled Trials as Topic , Sex Distribution , Time Factors , Ultrasonography
12.
Int J Immunogenet ; 36(4): 241-4, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19601999

ABSTRACT

Osteopontin (OPN) is a secreted glycoprotein demonstrated to play an important role in inflammation. Transforming growth factor beta and a related signalling pathway have been implicated in control of OPN secretion. We examined the relationship between transforming growth factor beta receptor-1 and -2 (TGFBR1 and 2) single nucleotide polymorphisms (SNP) and serum OPN in 296 men from the Health in Men Study. Serum concentrations of OPN and 58 SNPs for TGFBR1 and 2 were assessed. One SNP in TGFBR2 was associated with serum OPN (TGFBR2 g.20690C>T, SNP ID rs4522809, P = 0.0007) after adjusting for multiple testing. This study suggests that polymorphism in TGFBR2 are associated with altered secretion of OPN, supporting a role for transforming growth factor beta in OPN production.


Subject(s)
Osteopontin/blood , Protein Serine-Threonine Kinases/genetics , Receptors, Transforming Growth Factor beta/genetics , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/blood , Aortic Aneurysm, Abdominal/genetics , Cohort Studies , Gene Frequency/genetics , Humans , Male , Osteopontin/biosynthesis , Polymorphism, Single Nucleotide/genetics , Receptor, Transforming Growth Factor-beta Type I , Receptor, Transforming Growth Factor-beta Type II
13.
Eur J Vasc Endovasc Surg ; 38(2): 169-71, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19515587

ABSTRACT

OBJECTIVE: To investigate associations between two polymorphisms of the matrix metalloproteinase-2 gene (MMP2) and the incidence and progression of abdominal aortic aneurysm (AAA). METHODS: Cases and controls were recruited from a trial of screening for AAAs. The association between two variants of MMP2 (-1360C>T, and +649C>T) in men with AAA (n=678) and in controls (n=659) was examined using multivariate analyses. The association with AAA expansion (n=638) was also assessed. RESULTS: In multivariate analyses with adjustments for multiple testing, no association between either SNP and AAA presence or expansion was detected. CONCLUSION: MMP2 -1360C>T and +649C>T variants are not risk factors for AAA.


Subject(s)
Aortic Aneurysm, Abdominal/genetics , Matrix Metalloproteinase 2/genetics , Polymorphism, Single Nucleotide , Aortic Aneurysm, Abdominal/enzymology , Aortic Aneurysm, Abdominal/epidemiology , Case-Control Studies , Disease Progression , Gene Frequency , Genetic Predisposition to Disease , Humans , Incidence , Logistic Models , Male , Mass Screening , Odds Ratio , Phenotype , Risk Assessment , Risk Factors , Western Australia/epidemiology
14.
Br J Surg ; 96(6): 628-32, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19434696

ABSTRACT

BACKGROUND: Previous studies have suggested a role for transforming growth factor (TGF) beta and its receptor in thoracic aortic aneurysm, but their role in abdominal aortic aneurysm (AAA) is unknown. This study examined the possible association between TGF-beta receptor 1 and 2 (TGFBR-1 and -2) single nucleotide polymorphisms (SNPs) and serum TGF-beta1 with AAA. METHODS: Serum concentrations of TGF-beta1 and 58 SNPs for TGFBR-1 and -2 were examined in 1003 and 1711 men respectively from the Health In Men Study. Validation of SNPs was examined in a second referral cohort of 1043 subjects from New Zealand, of whom 654 had an AAA. RESULTS: Serum TGF-beta1 was not associated with AAA. Only one SNP in TGFBR-2 was weakly associated with AAA; TGFBR2 g.42917C > T, SNP ID rs1078985CC; odds ratio 0.64 (95 per cent confidence interval (c.i.) 0.45 to 0.93); P = 0.020 uncorrected; but this association did not hold after adjusting for multiple testing and was not validated in the New Zealand cohort: odds ratio 0.98 (95 per cent c.i. 0.50 to 1.94); P = 0.960. CONCLUSION: These findings suggest there is no important role of genetic polymorphisms in the main receptors for TGF-beta and circulating TGF-beta1 in AAA in older individuals. (c) 2009 British Journal of Surgery Society Ltd.


Subject(s)
Aortic Aneurysm, Abdominal/genetics , Polymorphism, Genetic/genetics , Receptors, Transforming Growth Factor beta/genetics , Transforming Growth Factor beta1/blood , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/blood , Enzyme-Linked Immunosorbent Assay , Epidemiologic Methods , Humans , Male , Protein Serine-Threonine Kinases/genetics , Receptor, Transforming Growth Factor-beta Type I , Receptor, Transforming Growth Factor-beta Type II , Risk Factors
15.
Br J Surg ; 95(10): 1239-44, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18763261

ABSTRACT

BACKGROUND: Increased matrix metalloproteinase (MMP) 9 activity has been implicated in the formation of abdominal aortic aneurysm (AAA). The aim was to explore the association between potentially functional variants of the MMP-9 gene and AAA. METHODS: The -1562C > T and -1811A > T variants of the MMP-9 gene were genotyped in 678 men with an AAA (at least 30 mm in diameter) and 659 control subjects (aortic diameter 19-22 mm) recruited from a population-based trial of screening for AAA. Levels of MMP-9 were measured in a random subset of 300 cases and 84 controls. The association between genetic variants (including haplotypes) and AAA was assessed by multivariable logistic regression. RESULTS: There was no association between the MMP-9-1562C > T (odds ratio (OR) 0.70 (95 per cent confidence interval (c.i.) 0.27 to 1.82)) or -1811A > T (OR 0.71 (95 per cent c.i. 0.28 to 1.85)) genotypes, or the most common haplotype (OR 0.81 (95 per cent c.i. 0.62 to 1.05)) and AAA. The serum MMP-9 concentration was higher in cases than controls, and in minor allele carriers in cases and controls, although the differences were not statistically significant. CONCLUSION: In this study, the genetic tendency to higher levels of circulating MMP-9 was not associated with AAA.


Subject(s)
Aortic Aneurysm, Abdominal/genetics , Matrix Metalloproteinase 9/genetics , Polymorphism, Genetic/genetics , Aged , Aged, 80 and over , Case-Control Studies , Genotype , Humans , Male , Matrix Metalloproteinase 9/metabolism
16.
JAMA ; 300(2): 197-208, 2008 Jul 09.
Article in English | MEDLINE | ID: mdl-18612117

ABSTRACT

CONTEXT: Prediction models to identify healthy individuals at high risk of cardiovascular disease have limited accuracy. A low ankle brachial index (ABI) is an indicator of atherosclerosis and has the potential to improve prediction. OBJECTIVE: To determine if the ABI provides information on the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS) and can improve risk prediction. DATA SOURCES: Relevant studies were identified. A search of MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) was conducted using common text words for the term ankle brachial index combined with text words and Medical Subject Headings to capture prospective cohort designs. Review of reference lists and conference proceedings, and correspondence with experts was conducted to identify additional published and unpublished studies. STUDY SELECTION: Studies were included if participants were derived from a general population, ABI was measured at baseline, and individuals were followed up to detect total and cardiovascular mortality. DATA EXTRACTION: Prespecified data on individuals in each selected study were extracted into a combined data set and an individual participant data meta-analysis was conducted on individuals who had no previous history of coronary heart disease. RESULTS: Sixteen population cohort studies fulfilling the inclusion criteria were included. During 480,325 person-years of follow-up of 24,955 men and 23,339 women, the risk of death by ABI had a reverse J-shaped distribution with a normal (low risk) ABI of 1.11 to 1.40. The 10-year cardiovascular mortality in men with a low ABI (< or = 0.90) was 18.7% (95% confidence interval [CI], 13.3%-24.1%) and with normal ABI (1.11-1.40) was 4.4% (95% CI, 3.2%-5.7%) (hazard ratio [HR], 4.2; 95% CI, 3.3-5.4). Corresponding mortalities in women were 12.6% (95% CI, 6.2%-19.0%) and 4.1% (95% CI, 2.2%-6.1%) (HR, 3.5; 95% CI, 2.4-5.1). The HRs remained elevated after adjusting for FRS (2.9 [95% CI, 2.3-3.7] for men vs 3.0 [95% CI, 2.0-4.4] for women). A low ABI (< or = 0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each FRS category. Inclusion of the ABI in cardiovascular risk stratification using the FRS would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women. CONCLUSION: Measurement of the ABI may improve the accuracy of cardiovascular risk prediction beyond the FRS.


Subject(s)
Ankle , Blood Pressure , Brachial Artery , Cardiovascular Diseases/mortality , Cardiovascular Diseases/physiopathology , Adult , Age Factors , Aged , Aged, 80 and over , Atherosclerosis/physiopathology , Cohort Studies , Confidence Intervals , Female , Global Health , Humans , Male , Middle Aged , Odds Ratio , Predictive Value of Tests , Risk Assessment , Risk Factors , Severity of Illness Index
17.
Eur J Vasc Endovasc Surg ; 35(1): 31-6, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17996468

ABSTRACT

BACKGROUND: Elevated levels of circulating interleukin-6 (IL-6) have been reported in patients with abdominal aortic aneurysms (AAAs). Although this implicates inflammation as a cause of AAAs, there is also evidence that the aneurysmal aorta may secrete IL-6 into the circulation as a result of aortic proteolysis. Genetic association studies are one means of trying to clarify the role of specific mediators in the causal pathway. The aim of the present study was to examine the association between variants of the IL-6 gene and AAAs. METHODS: An association study involving 677 men with screen-detected AAAs and 656 age-matched controls was performed. Three variants in the IL-6 promoter region were analysed: IL-6-174G>C (rs1800795), IL-6-572G>C (rs1800796) and IL-6-597G>A (rs1800797). Univariate regression of SNP genotype on AAA as a binary outcome was initially performed under a range of genetic models (additive, dominant and recessive). This was followed by multivariate analyses, testing the same models but including risk factors known to be associated with AAAs. All analyses and haplotype estimation were performed under a generalized linear model framework. RESULTS: IL-6-572G>C polymorphism (frequency 1.5% in cases) was identified as an independent risk factor for AAA with an odds ratio (OR) of 6.00 (95%CI: 1.22, 29.41) when applied to the recessive model. No association was seen in the additive or dominant models. In a multivariate analysis using the most common haplotype (h.111, frequency 48.7%) as a reference, h.211 (frequency 4.4%) was an independent risk factor for AAA (OR 1.56, 95%CI: 1.02, 2.39). CONCLUSION: The IL-6 572G>C polymorphism (and h.211 haplotype) is associated with AAA, however it is too rare to be an important cause of most AAAs. This does not support the concept that the elevated level of IL-6 reported in patients with AAAs is a primary cause of the aneurysmal process.


Subject(s)
Aortic Aneurysm, Abdominal/genetics , Interleukin-6/genetics , Polymorphism, Single Nucleotide , Promoter Regions, Genetic , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/blood , Case-Control Studies , Gene Frequency , Genetic Predisposition to Disease , Haplotypes , Humans , Interleukin-6/blood , Male , Multivariate Analysis , Odds Ratio , Risk Assessment , Risk Factors
19.
Eur J Vasc Endovasc Surg ; 33(5): 599-604, 2007 May.
Article in English | MEDLINE | ID: mdl-17307366

ABSTRACT

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.


Subject(s)
Aorta, Abdominal/pathology , Aortic Aneurysm, Abdominal/epidemiology , Diabetes Mellitus/epidemiology , Diabetic Angiopathies/epidemiology , Aged , Aortic Aneurysm, Abdominal/physiopathology , Blood Glucose/analysis , Comorbidity , Diabetes Mellitus/physiopathology , Diabetic Angiopathies/physiopathology , Humans , Logistic Models , Male
20.
Diabetologia ; 49(11): 2634-41, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17001469

ABSTRACT

AIMS/HYPOTHESIS: The aims of this study were to assess the incidence, predictors, consequences, and inpatient cost of lower extremity amputation (LEA) in a community-based cohort of type 2 diabetic patients. METHODS: Between 1993 and 1996, 1,294 patients with type 2 diabetes were recruited to the longitudinal, observational Fremantle Diabetes Study. LEAs and mortality from cardiac causes were monitored until 30 June 2005. Inpatient costs (in Australian dollars in year 2000), derived using a case-mix approach, were available for the period from 1 July 1993 to 30 June 2000. RESULTS: During follow-up 44 patients without LEA at baseline had a first-ever diabetes-related LEA, an incidence of 3.8 per 1,000 patient-years. Independent predictors of first-ever LEA included foot ulceration (hazard ratio [95% CI]: 5.56 [1.24-25.01]), an ankle brachial index < or =0.90 (2.21 [1.11-4.42]), HbA(1c) (increase of 1%: 1.30 [1.10-1.54]) and neuropathy (2.65 [1.30-5.44]). The risk of cardiac death was significantly increased in patients with LEA at baseline, although this was not an independent risk factor. The median (interquartile range) inpatient cost per LEA admission was 12,485 Australian dollars (6,037 Australian dollars-24,415 Australian dollars), with a median length of stay of 24 (10-43) days. CONCLUSIONS/INTERPRETATION: First-ever LEAs in type 2 patients were associated with poor glycaemic control, foot ulceration and evidence of microvascular and macrovascular disease. Patients with LEA were at increased risk of cardiac death. LEAs contribute disproportionately to diabetes-related inpatient costs.


Subject(s)
Amputation, Surgical/statistics & numerical data , Diabetes Mellitus, Type 2/complications , Diabetic Foot/surgery , Leg/surgery , Aged , Amputation, Surgical/economics , Blood Pressure , Body Mass Index , Costs and Cost Analysis , Diabetic Nephropathies/epidemiology , Diabetic Neuropathies/epidemiology , Female , Humans , Longitudinal Studies , Male , Middle Aged , Obesity/epidemiology , Predictive Value of Tests , Western Australia
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