@article {1130, title = {Association of chronic kidney disease with the spectrum of ankle brachial index the CHS (Cardiovascular Health Study).}, journal = {J Am Coll Cardiol}, volume = {54}, year = {2009}, month = {2009 Sep 22}, pages = {1176-84}, abstract = {

OBJECTIVES: This study sought to determine the association of chronic kidney disease (CKD) with high ankle brachial index (ABI) measurement and to compare its strength with that of CKD with a low ABI.

BACKGROUND: CKD is an important risk factor for cardiovascular disease (CVD) events. A high ABI, a marker of lower extremity arterial stiffness, is associated with CVD events and mortality. The association between CKD and high ABI is unknown.

METHODS: The CHS (Cardiovascular Health Study) enrolled community-living people >65 years of age and measured kidney function and ABI. Glomerular filtration rate (GFR) was estimated using equations that incorporated either cystatin C or creatinine, and CKD was defined by estimated GFR <60 ml/min/1.73 m(2). The ABI was categorized as low (<0.90), low-normal (0.90 to 1.09), normal (1.10 to 1.40), and high (>1.40 or incompressible). Multinomial logistic regression was used to evaluate the associations of CKD with ABI categories.

RESULTS: Among 4,513 participants, 23\% had CKD, 13\% had a low ABI, and 3\% had a high ABI. In models adjusted for age, sex, race, hypertension, diabetes, smoking, body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and C-reactive protein, cystatin C-based CKD was associated with both low ABI (relative risk [RR]: 2.0; 95\% confidence interval [CI]: 1.6 to 2.5; p <0.001) and high ABI (RR: 1.6; 95\% CI: 1.0 to 2.3; p = 0.03). Results were similar when CKD was defined by creatinine.

CONCLUSIONS: CKD is associated with both the high and the low extremes of ABI in community-living older people. Future studies should evaluate whether arterial stiffness is an important mechanism leading to CVD in people with CKD.

}, keywords = {Aged, Aged, 80 and over, Ankle Brachial Index, C-Reactive Protein, Cardiovascular Diseases, Chronic Disease, Cohort Studies, Cross-Sectional Studies, Female, Glomerular Filtration Rate, Humans, Kidney Diseases, Lipids, Male, Risk Factors}, issn = {1558-3597}, doi = {10.1016/j.jacc.2009.06.017}, author = {Ix, Joachim H and Katz, Ronit and de Boer, Ian H and Kestenbaum, Brian R and Allison, Matthew A and Siscovick, David S and Newman, Anne B and Sarnak, Mark J and Shlipak, Michael G and Criqui, Michael H} } @article {1109, title = {Admixture mapping of ankle-arm index: identification of a candidate locus associated with peripheral arterial disease.}, journal = {J Med Genet}, volume = {47}, year = {2010}, month = {2010 Jan}, pages = {1-7}, abstract = {

BACKGROUND: Peripheral arterial disease (PAD) is associated with significant morbidity and mortality, and has a higher prevalence in African Americans than Caucasians. Ankle-arm index (AAI) is the ratio of systolic blood pressure in the leg to that in the arm, and, when low, is a marker of PAD.

METHODS: The authors used an admixture mapping approach to search for genetic loci associated with low AAI. Using data from 1040 African American participants in the observational, population based Health, Aging, and Body Composition Study who were genotyped at 1322 single nucleotide polymorphisms (SNPs) that are informative for African versus European ancestry and span the entire genome, we estimated genetic ancestry in each chromosomal region and then tested the association between AAI and genetic ancestry at each locus.

RESULTS: The authors found a region of chromosome 11 that reaches its peak between 80 and 82 Mb associated with low AAI (p<0.001 for rs12289502 and rs9665943, both within this region). 753 African American participants in the observational, population based Cardiovascular Health Study were genotyped at rs9665943 to test the reproducibility of this association, and this association was also statistically significant (odds ratio (OR) for homozygous African genotype 1.59, 95\% confidence interval (CI) 1.12 to 2.27). Another candidate SNP (rs1042602) in the same genomic region was tested in both populations, and was also found to be significantly associated with low AAI in both populations (OR for homozygous African genotype 1.89, 95\% CI 1.29 to 2.76).

CONCLUSION: This study identifies a novel region of chromosome 11 representing an area with a potential candidate gene associated with PAD in African Americans.

}, keywords = {African Americans, Aged, Ankle Brachial Index, Chromosome Mapping, Chromosomes, Human, Pair 11, Female, Genetic Loci, Genotype, Humans, Male, Odds Ratio, Peripheral Vascular Diseases, Polymorphism, Single Nucleotide}, issn = {1468-6244}, doi = {10.1136/jmg.2008.064808}, author = {Scherer, M L and Nalls, M A and Pawlikowska, L and Ziv, E and Mitchell, G and Huntsman, S and Hu, D and Sutton-Tyrrell, K and Lakatta, E G and Hsueh, W-C and Newman, A B and Tandon, A and Kim, L and Kwok, P-Y and Sung, A and Li, R and Psaty, B and Reiner, A P and Harris, T} } @article {1326, title = {Association of body mass index with peripheral arterial disease in older adults: the Cardiovascular Health Study.}, journal = {Am J Epidemiol}, volume = {174}, year = {2011}, month = {2011 Nov 01}, pages = {1036-43}, abstract = {

The authors hypothesized that the absence of cross-sectional associations of body mass index (BMI; weight (kg)/height (m)(2)) with peripheral arterial disease (PAD) in prior studies may reflect lower weight among persons who smoke or have poor health status. They conducted an observational study among 5,419 noninstitutionalized residents of 4 US communities aged >= 65 years at baseline (1989-1990 or 1992-1993). Ankle brachial index was measured, and participants reported their history of PAD procedures. Participants were followed longitudinally for adjudicated incident PAD events. At baseline, mean BMI was 26.6 (standard deviation, 4.6), and 776 participants (14\%) had prevalent PAD. During 13.2 (median) years of follow-up through June 30, 2007, 276 incident PAD events occurred. In cross-sectional analysis, each 5-unit increase in BMI was inversely associated with PAD (prevalence ratio (PR) = 0.92, 95\% confidence interval (CI): 0.85, 1.00). However, among persons in good health who had never smoked, the direction of association was opposite (PR = 1.20, 95\% CI: 0.94, 1.52). Similar results were observed between BMI calculated using weight at age 50 years and PAD prevalence (PR = 1.30, 95\% CI: 1.11, 1.51) and between BMI at baseline and incident PAD events occurring during follow-up (hazard ratio = 1.32, 95\% CI: 1.00, 1.76) among never smokers in good health. Greater BMI is associated with PAD in older persons who remain healthy and have never smoked. Normal weight maintenance may decrease PAD incidence and associated comorbidity in older age.

}, keywords = {Aged, Ankle Brachial Index, Body Mass Index, Cross-Sectional Studies, Health Status, Humans, Kaplan-Meier Estimate, Longitudinal Studies, Male, Obesity, Peripheral Arterial Disease, Prevalence, Sex Factors, Smoking, United States}, issn = {1476-6256}, doi = {10.1093/aje/kwr228}, author = {Ix, Joachim H and Biggs, Mary L and Kizer, Jorge R and Mukamal, Kenneth J and Djouss{\'e}, Luc and Zieman, Susan J and de Boer, Ian H and Nelson, Tracy L and Newman, Anne B and Criqui, Michael H and Siscovick, David S} } @article {1359, title = {Association between chromosome 9p21 variants and the ankle-brachial index identified by a meta-analysis of 21 genome-wide association studies.}, journal = {Circ Cardiovasc Genet}, volume = {5}, year = {2012}, month = {2012 Feb 01}, pages = {100-12}, abstract = {

BACKGROUND: Genetic determinants of peripheral arterial disease (PAD) remain largely unknown. To identify genetic variants associated with the ankle-brachial index (ABI), a noninvasive measure of PAD, we conducted a meta-analysis of genome-wide association study data from 21 population-based cohorts.

METHODS AND RESULTS: Continuous ABI and PAD (ABI <=0.9) phenotypes adjusted for age and sex were examined. Each study conducted genotyping and imputed data to the ≈2.5 million single nucleotide polymorphisms (SNPs) in HapMap. Linear and logistic regression models were used to test each SNP for association with ABI and PAD using additive genetic models. Study-specific data were combined using fixed effects inverse variance weighted meta-analyses. There were a total of 41 692 participants of European ancestry (≈60\% women, mean ABI 1.02 to 1.19), including 3409 participants with PAD and with genome-wide association study data available. In the discovery meta-analysis, rs10757269 on chromosome 9 near CDKN2B had the strongest association with ABI (β=-0.006, P=2.46{\texttimes}10(-8)). We sought replication of the 6 strongest SNP associations in 5 population-based studies and 3 clinical samples (n=16 717). The association for rs10757269 strengthened in the combined discovery and replication analysis (P=2.65{\texttimes}10(-9)). No other SNP associations for ABI or PAD achieved genome-wide significance. However, 2 previously reported candidate genes for PAD and 1 SNP associated with coronary artery disease were associated with ABI: DAB21P (rs13290547, P=3.6{\texttimes}10(-5)), CYBA (rs3794624, P=6.3{\texttimes}10(-5)), and rs1122608 (LDLR, P=0.0026).

CONCLUSIONS: Genome-wide association studies in more than 40 000 individuals identified 1 genome wide significant association on chromosome 9p21 with ABI. Two candidate genes for PAD and 1 SNP for coronary artery disease are associated with ABI.

}, keywords = {Adult, Age Factors, Aged, Aged, 80 and over, Alleles, Ankle Brachial Index, Chromosomes, Human, Pair 9, Cohort Studies, Cyclin-Dependent Kinase Inhibitor p15, Female, Genome-Wide Association Study, Genotype, HapMap Project, Humans, Logistic Models, Male, Middle Aged, Peripheral Vascular Diseases, Phenotype, Polymorphism, Single Nucleotide, Risk Factors, Sex Factors}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.111.961292}, author = {Murabito, Joanne M and White, Charles C and Kavousi, Maryam and Sun, Yan V and Feitosa, Mary F and Nambi, Vijay and Lamina, Claudia and Schillert, Arne and Coassin, Stefan and Bis, Joshua C and Broer, Linda and Crawford, Dana C and Franceschini, Nora and Frikke-Schmidt, Ruth and Haun, Margot and Holewijn, Suzanne and Huffman, Jennifer E and Hwang, Shih-Jen and Kiechl, Stefan and Kollerits, Barbara and Montasser, May E and Nolte, Ilja M and Rudock, Megan E and Senft, Andrea and Teumer, Alexander and van der Harst, Pim and Vitart, Veronique and Waite, Lindsay L and Wood, Andrew R and Wassel, Christina L and Absher, Devin M and Allison, Matthew A and Amin, Najaf and Arnold, Alice and Asselbergs, Folkert W and Aulchenko, Yurii and Bandinelli, Stefania and Barbalic, Maja and Boban, Mladen and Brown-Gentry, Kristin and Couper, David J and Criqui, Michael H and Dehghan, Abbas and den Heijer, Martin and Dieplinger, Benjamin and Ding, Jingzhong and D{\"o}rr, Marcus and Espinola-Klein, Christine and Felix, Stephan B and Ferrucci, Luigi and Folsom, Aaron R and Fraedrich, Gustav and Gibson, Quince and Goodloe, Robert and Gunjaca, Grgo and Haltmayer, Meinhard and Heiss, Gerardo and Hofman, Albert and Kieback, Arne and Kiemeney, Lambertus A and Kolcic, Ivana and Kullo, Iftikhar J and Kritchevsky, Stephen B and Lackner, Karl J and Li, Xiaohui and Lieb, Wolfgang and Lohman, Kurt and Meisinger, Christa and Melzer, David and Mohler, Emile R and Mudnic, Ivana and Mueller, Thomas and Navis, Gerjan and Oberhollenzer, Friedrich and Olin, Jeffrey W and O{\textquoteright}Connell, Jeff and O{\textquoteright}Donnell, Christopher J and Palmas, Walter and Penninx, Brenda W and Petersmann, Astrid and Polasek, Ozren and Psaty, Bruce M and Rantner, Barbara and Rice, Ken and Rivadeneira, Fernando and Rotter, Jerome I and Seldenrijk, Adrie and Stadler, Marietta and Summerer, Monika and Tanaka, Toshiko and Tybjaerg-Hansen, Anne and Uitterlinden, Andr{\'e} G and van Gilst, Wiek H and Vermeulen, Sita H and Wild, Sarah H and Wild, Philipp S and Willeit, Johann and Zeller, Tanja and Zemunik, Tatijana and Zgaga, Lina and Assimes, Themistocles L and Blankenberg, Stefan and Boerwinkle, Eric and Campbell, Harry and Cooke, John P and de Graaf, Jacqueline and Herrington, David and Kardia, Sharon L R and Mitchell, Braxton D and Murray, Anna and M{\"u}nzel, Thomas and Newman, Anne B and Oostra, Ben A and Rudan, Igor and Shuldiner, Alan R and Snieder, Harold and van Duijn, Cornelia M and V{\"o}lker, Uwe and Wright, Alan F and Wichmann, H-Erich and Wilson, James F and Witteman, Jacqueline C M and Liu, Yongmei and Hayward, Caroline and Borecki, Ingrid B and Ziegler, Andreas and North, Kari E and Cupples, L Adrienne and Kronenberg, Florian} } @article {5864, title = {Genetic determinants of the ankle-brachial index: a meta-analysis of a cardiovascular candidate gene 50K SNP panel in the candidate gene association resource (CARe) consortium.}, journal = {Atherosclerosis}, volume = {222}, year = {2012}, month = {2012 May}, pages = {138-47}, abstract = {

BACKGROUND: Candidate gene association studies for peripheral artery disease (PAD), including subclinical disease assessed with the ankle-brachial index (ABI), have been limited by the modest number of genes examined. We conducted a two stage meta-analysis of \~{}50,000 SNPs across \~{}2100 candidate genes to identify genetic variants for ABI.

METHODS AND RESULTS: We studied subjects of European ancestry from 8 studies (n=21,547, 55\% women, mean age 44-73 years) and African American ancestry from 5 studies (n=7267, 60\% women, mean age 41-73 years) involved in the candidate gene association resource (CARe) consortium. In each ethnic group, additive genetic models were used (with each additional copy of the minor allele corresponding to the given beta) to test each SNP for association with continuous ABI (excluding ABI>1.40) and PAD (defined as ABI<0.90) using linear or logistic regression with adjustment for known PAD risk factors and population stratification. We then conducted a fixed-effects inverse-variance weighted meta-analyses considering a p<2{\texttimes}10(-6) to denote statistical significance.

RESULTS: In the European ancestry discovery meta-analyses, rs2171209 in SYTL3 (β=-0.007, p=6.02{\texttimes}10(-7)) and rs290481 in TCF7L2 (β=-0.008, p=7.01{\texttimes}10(-7)) were significantly associated with ABI. None of the SNP associations for PAD were significant, though a SNP in CYP2B6 (p=4.99{\texttimes}10(-5)) was among the strongest associations. These 3 genes are linked to key PAD risk factors (lipoprotein(a), type 2 diabetes, and smoking behavior, respectively). We sought replication in 6 population-based and 3 clinical samples (n=15,440) for rs290481 and rs2171209. However, in the replication stage (rs2171209, p=0.75; rs290481, p=0.19) and in the combined discovery and replication analysis the SNP-ABI associations were no longer significant (rs2171209, p=1.14{\texttimes}10(-3); rs290481, p=8.88{\texttimes}10(-5)). In African Americans, none of the SNP associations for ABI or PAD achieved an experiment-wide level of significance.

CONCLUSIONS: Genetic determinants of ABI and PAD remain elusive. Follow-up of these preliminary findings may uncover important biology given the known gene-risk factor associations. New and more powerful approaches to PAD gene discovery are warranted.

}, keywords = {Adult, African Americans, Aged, Ankle Brachial Index, Aryl Hydrocarbon Hydroxylases, Cytochrome P-450 CYP2B6, European Continental Ancestry Group, Female, Humans, Male, Middle Aged, Oxidoreductases, N-Demethylating, Peripheral Arterial Disease, Polymorphism, Single Nucleotide, Risk Factors, Transcription Factor 7-Like 2 Protein}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2012.01.039}, author = {Wassel, Christina L and Lamina, Claudia and Nambi, Vijay and Coassin, Stefan and Mukamal, Kenneth J and Ganesh, Santhi K and Jacobs, David R and Franceschini, Nora and Papanicolaou, George J and Gibson, Quince and Yanek, Lisa R and van der Harst, Pim and Ferguson, Jane F and Crawford, Dana C and Waite, Lindsay L and Allison, Matthew A and Criqui, Michael H and McDermott, Mary M and Mehra, Reena and Cupples, L Adrienne and Hwang, Shih-Jen and Redline, Susan and Kaplan, Robert C and Heiss, Gerardo and Rotter, Jerome I and Boerwinkle, Eric and Taylor, Herman A and Eraso, Luis H and Haun, Margot and Li, Mingyao and Meisinger, Christa and O{\textquoteright}Connell, Jeffrey R and Shuldiner, Alan R and Tybj{\ae}rg-Hansen, Anne and Frikke-Schmidt, Ruth and Kollerits, Barbara and Rantner, Barbara and Dieplinger, Benjamin and Stadler, Marietta and Mueller, Thomas and Haltmayer, Meinhard and Klein-Weigel, Peter and Summerer, Monika and Wichmann, H-Erich and Asselbergs, Folkert W and Navis, Gerjan and Mateo Leach, Irene and Brown-Gentry, Kristin and Goodloe, Robert and Assimes, Themistocles L and Becker, Diane M and Cooke, John P and Absher, Devin M and Olin, Jeffrey W and Mitchell, Braxton D and Reilly, Muredach P and Mohler, Emile R and North, Kari E and Reiner, Alexander P and Kronenberg, Florian and Murabito, Joanne M} } @article {5860, title = {Hemoglobin A1c and arterial and ventricular stiffness in older adults.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012}, pages = {e47941}, abstract = {

OBJECTIVE: Arterial and ventricular stiffening are characteristics of diabetes and aging which confer significant morbidity and mortality; advanced glycation endproducts (AGE) are implicated in this stiffening pathophysiology. We examined the association between HbA(1c), an AGE, with arterial and ventricular stiffness measures in older individuals without diabetes.

RESEARCH DESIGN \& METHODS: Baseline HbA(1c) was measured in 830 participants free of diabetes defined by fasting glucose or medication use in the Cardiovascular Health Study, a population-based cohort study of adults aged >= 65 years. We performed cross-sectional analyses using baseline exam data including echocardiography, ankle and brachial blood pressure measurement, and carotid ultrasonography. We examined the adjusted associations between HbA(1c) and multiple arterial and ventricular stiffness measures by linear regression models and compared these results to the association of fasting glucose (FG) with like measures.

RESULTS: HbA(1c) was correlated with fasting and 2-hour postload glucose levels (r = 0.21; p<0.001 for both) and positively associated with greater body-mass index and black race. In adjusted models, HbA(1c) was not associated with any measure of arterial or ventricular stiffness, including pulse pressure (PP), carotid intima-media thickness, ankle-brachial index, end-arterial elastance, or left ventricular mass (LVM). FG levels were positively associated with systolic, diastolic and PP and LVM.

CONCLUSIONS: In this sample of older adults without diabetes, HbA(1c) was not associated with arterial or ventricular stiffness measures, whereas FG levels were. The role of AGE in arterial and ventricular stiffness in older adults may be better assessed using alternate AGE markers.

}, keywords = {Adult, African Continental Ancestry Group, Aged, Ankle Brachial Index, Arteries, Blood Glucose, Blood Pressure, Body Mass Index, Cross-Sectional Studies, Fasting, Female, Genetic Association Studies, Glycated Hemoglobin A, Glycation End Products, Advanced, Heart Ventricles, Humans, Male, Middle Aged, Ultrasonography, Vascular Stiffness}, issn = {1932-6203}, doi = {10.1371/journal.pone.0047941}, author = {Zieman, Susan J and Kamineni, Aruna and Ix, Joachim H and Barzilay, Joshua and Djouss{\'e}, Luc and Kizer, Jorge R and Biggs, Mary L and de Boer, Ian H and Chonchol, Michel and Gottdiener, John S and Selvin, Elizabeth and Newman, Anne B and Kuller, Lewis H and Siscovick, David S and Mukamal, Kenneth J} } @article {1370, title = {Insulin resistance and incident peripheral artery disease in the Cardiovascular Health Study.}, journal = {Vasc Med}, volume = {17}, year = {2012}, month = {2012 Apr}, pages = {85-93}, abstract = {

Type 2 diabetes is a risk factor for peripheral artery disease (PAD), and insulin resistance is a key feature of diabetes and pre-diabetes. No longitudinal epidemiological study has examined the relation between insulin resistance and PAD. Our study analyzed the association of quartiles of the homeostatic model of insulin resistance (HOMA-IR) and the development of PAD defined by two methods. PAD was first defined as the development of an abnormal ankle-brachial index (ABI) (dichotomous outcome) after 6 years of follow-up. PAD was alternatively defined as the development of clinical PAD (time-to-event analysis). The study samples included adults over the age of 65 years who were enrolled in the Cardiovascular Health Study, had fasting measurements of insulin and glucose, had ABI measurements, and were not receiving treatment for diabetes. Multivariable models were adjusted for potential confounders, including age, sex, field center and cohort, body mass index (BMI), smoking status, alcohol use, and exercise intensity. Additional models adjusted for potential mediators, including blood pressure, lipids, kidney function, and prevalent vascular disease. In the ABI analysis (n = 2108), multivariable adjusted models demonstrated a positive relation between HOMA-IR and incident PAD (odds ratio = 1.80 comparing the 4th versus 1st quartile of HOMA-IR, 95\% confidence interval [CI] 1.20-2.71). In the clinical PAD analysis (n = 4208), we found a similar relation (hazard ratio = 2.30 comparing the 4th versus 1st quartile of HOMA-IR, 95\% CI 1.15-4.58). As expected, further adjustment for potential mediators led to some attenuation of effect estimates. In conclusion, insulin resistance is associated with a higher risk of PAD in older adults.

}, keywords = {Aged, Ankle Brachial Index, Biomarkers, Blood Glucose, Diabetes Mellitus, Type 2, Diabetic Angiopathies, Fasting, Female, Health Surveys, Humans, Incidence, Insulin, Insulin Resistance, Logistic Models, Longitudinal Studies, Male, Odds Ratio, Peripheral Arterial Disease, Predictive Value of Tests, Proportional Hazards Models, Prospective Studies, Risk Assessment, Risk Factors, Time Factors, United States}, issn = {1477-0377}, doi = {10.1177/1358863X11436195}, author = {Britton, Kathryn A and Mukamal, Kenneth J and Ix, Joachim H and Siscovick, David S and Newman, Anne B and de Boer, Ian H and Thacker, Evan L and Biggs, Mary L and Gaziano, J Michael and Djouss{\'e}, Luc} } @article {6094, title = {Lack of associations of ten candidate coronary heart disease risk genetic variants and subclinical atherosclerosis in four US populations: the Population Architecture using Genomics and Epidemiology (PAGE) study.}, journal = {Atherosclerosis}, volume = {228}, year = {2013}, month = {2013 Jun}, pages = {390-9}, abstract = {

BACKGROUND: A number of genetic variants have been discovered by recent genome-wide association studies for their associations with clinical coronary heart disease (CHD). However, it is unclear whether these variants are also associated with the development of CHD as measured by subclinical atherosclerosis phenotypes, ankle brachial index (ABI), carotid artery intima-media thickness (cIMT) and carotid plaque.

METHODS: Ten CHD risk single nucleotide polymorphisms (SNPs) were genotyped in individuals of European American (EA), African American (AA), American Indian (AI), and Mexican American (MA) ancestry in the Population Architecture using Genomics and Epidemiology (PAGE) study. In each individual study, we performed linear or logistic regression to examine population-specific associations between SNPs and ABI, common and internal cIMT, and plaque. The results from individual studies were meta-analyzed using a fixed effect inverse variance weighted model.

RESULTS: None of the ten SNPs was significantly associated with ABI and common or internal cIMT, after Bonferroni correction. In the sample of 13,337 EA, 3809 AA, and 5353 AI individuals with carotid plaque measurement, the GCKR SNP rs780094 was significantly associated with the presence of plaque in AI only (OR~=~1.32, 95\% confidence interval: 1.17, 1.49, P~=~1.08~{\texttimes}~10(-5)), but not in the other populations (P~=~0.90 in EA and P~=~0.99 in AA). A 9p21 region SNP, rs1333049, was nominally associated with plaque in EA (OR~=~1.07, P~=~0.02) and in AI (OR~=~1.10, P~=~0.05).

CONCLUSIONS: We identified a significant association between rs780094 and plaque in AI populations, which needs to be replicated in future studies. There was little evidence that the index CHD risk variants identified through genome-wide association studies in EA influence the development of CHD through subclinical atherosclerosis as assessed by cIMT and ABI across ancestries.

}, keywords = {African Americans, Aged, Ankle Brachial Index, Asymptomatic Diseases, Carotid Artery Diseases, Carotid Intima-Media Thickness, Coronary Disease, European Continental Ancestry Group, Female, Gene Frequency, Genetic Association Studies, Genetic Predisposition to Disease, Humans, Indians, North American, Linear Models, Logistic Models, Male, Mexican Americans, Middle Aged, Odds Ratio, Phenotype, Polymorphism, Single Nucleotide, Predictive Value of Tests, Risk Assessment, Risk Factors, United States}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2013.02.038}, author = {Zhang, Lili and B{\r u}zkov{\'a}, Petra and Wassel, Christina L and Roman, Mary J and North, Kari E and Crawford, Dana C and Boston, Jonathan and Brown-Gentry, Kristin D and Cole, Shelley A and Deelman, Ewa and Goodloe, Robert and Wilson, Sarah and Heiss, Gerardo and Jenny, Nancy S and Jorgensen, Neal W and Matise, Tara C and McClellan, Bob E and Nato, Alejandro Q and Ritchie, Marylyn D and Franceschini, Nora and Kao, W H Linda} } @article {6803, title = {Development and validation of an ankle brachial index risk model for the prediction of cardiovascular events.}, journal = {Eur J Prev Cardiol}, volume = {21}, year = {2014}, month = {2014 Mar}, pages = {310-20}, abstract = {

BACKGROUND: The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS.

DESIGN: An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events.

METHODS: Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events.

RESULTS: In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95\% CI 0.599 to 0.737) in men and 0.578 (95\% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95\% CI 0.612 to 0.749) and large increase in women to 0.690 (95\% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3\% (95\% CI 0.0 to 7.6\%, p = 0.050) and 9.6\% (95\% CI 6.1 to 16.4\%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19\% resulted in higher NRI of 15.9\% (95\% CI 6.1 to 20.6\%, p < 0.001) in men and 23.3\% (95\% CI 13.8 to 62.5\%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0\% (95\% CI 2.3 to 4.2\%, p = 0.567) in men and 1.1\% (95\% CI 1.9 to 4.0\%, p = 0.483) in women.

CONCLUSIONS: An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.

}, keywords = {Adult, Aged, Aged, 80 and over, Ankle Brachial Index, Cardiovascular Diseases, Europe, European Continental Ancestry Group, Female, Humans, Male, Middle Aged, Models, Statistical, Predictive Value of Tests, Prognosis, Reproducibility of Results, Risk Assessment, Risk Factors, Sex Factors, Time Factors, United States, Young Adult}, issn = {2047-4881}, doi = {10.1177/2047487313516564}, author = {Fowkes, F G R and Murray, G D and Butcher, I and Folsom, A R and Hirsch, A T and Couper, D J and deBacker, G and Kornitzer, M and Newman, A B and Sutton-Tyrrell, K C and Cushman, M and Lee, A J and Price, J F and D{\textquoteright}Agostino, R B and Murabito, J M and Norman, Pe and Masaki, K H and Bouter, L M and Heine, R J and Stehouwer, C D A and McDermott, M M and Stoffers, H E J H and Knottnerus, J A and Ogren, M and Hedblad, B and Koenig, W and Meisinger, C and Cauley, J A and Franco, Oh and Hunink, M G M and Hofman, A and Witteman, J C and Criqui, M H and Langer, R D and Hiatt, W R and Hamman, R F} } @article {6239, title = {Fibroblast growth factor 23, the ankle-brachial index, and incident peripheral artery disease in the Cardiovascular Health Study.}, journal = {Atherosclerosis}, volume = {233}, year = {2014}, month = {2014 Mar}, pages = {91-6}, abstract = {

BACKGROUND: Fibroblast growth factor 23 (FGF23) has emerged as a novel risk factor for mortality and cardiovascular events. Its association with the ankle-brachial index (ABI) and clinical peripheral artery disease (PAD) is less known.

METHODS: Using data (N = 3143) from the Cardiovascular Health Study (CHS), a cohort of community dwelling adults >65 years of age, we analyzed the cross-sectional association of FGF23 with ABI and its association with incident clinical PAD events during 9.8 years of follow up using multinomial logistic regression and Cox proportional hazards models respectively.

RESULTS: The prevalence of cardiovascular disease (CVD) and traditional risk factors like diabetes, coronary artery disease, and heart failure increased across higher quartiles of FGF23. Compared to those with ABI of 1.1-1.4, FGF23 per doubling at baseline was associated with prevalent PAD (ABI < 0.9) although this association was attenuated after adjusting for CVD risk factors, and kidney function (OR 0.91, 95\% CI 0.76-1.08). FGF23 was not associated with high ABI (>1.4) (OR 1.06, 95\% CI 0.75-1.51). Higher FGF23 was associated with incidence of PAD events in unadjusted, demographic adjusted, and CVD risk factor adjusted models (HR 2.26, 95\% CI 1.28-3.98; highest versus lowest quartile). The addition of estimated glomerular filtration and urine albumin to creatinine ratio to the model however, attenuated these findings (HR 1.46, 95\% CI, 0.79-2.70).

CONCLUSIONS: In community dwelling older adults, FGF23 was not associated with baseline low or high ABI or incident PAD events after adjusting for confounding variables. These results suggest that FGF23 may primarily be associated with adverse cardiovascular outcomes through non atherosclerotic mechanisms.

}, keywords = {Aged, Ankle Brachial Index, Cardiovascular Diseases, Cross-Sectional Studies, Fibroblast Growth Factors, Humans, Incidence, Peripheral Arterial Disease, Risk Factors}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2013.12.015}, author = {Garimella, Pranav S and Ix, Joachim H and Katz, Ronit and Chonchol, Michel B and Kestenbaum, Bryan R and de Boer, Ian H and Siscovick, David S and Shastri, Shani and Hiramoto, Jade S and Shlipak, Michael G and Sarnak, Mark J} } @article {6148, title = {Metabolic syndrome and risk of incident peripheral artery disease: the cardiovascular health study.}, journal = {Hypertension}, volume = {63}, year = {2014}, month = {2014 Feb}, pages = {413-9}, abstract = {

Prior studies evaluating metabolic syndrome (MetS) and incident peripheral artery disease (PAD) have been limited by use of modified MetS criteria and restriction to clinical PAD end points. We investigated MetS and risk of developing a low ankle-brachial index (ABI) and clinical PAD in the Cardiovascular Health Study, a population-based cohort of adults aged >=65 years. Participants with MetS met at least 3 of 5 Adult Treatment Panel III criteria. Baseline C-reactive protein-MetS or fibrinogen-MetS were defined as presence of 3 of 6 components, with elevated C-reactive protein (>3 mg/L) or fibrinogen (>341 mg/dL) as a sixth component. Incident low ABI, defined as ABI <0.9 and decline of >=0.15, was assessed among a subset of 1899 individuals with 2 ABI measurements 6 years apart. Over a median follow-up of 13.7 years, 4632 individuals were followed up for clinical PAD, defined as revascularization or diagnosed claudication. Adult Treatment Panel III MetS was associated with both incident low ABI (risk ratio, 1.26; 95\% confidence interval [CI], 1.00-1.58) and clinical PAD (hazard ratio, 1.47; 95\% CI, 1.11-1.94). Incorporating C-reactive protein or fibrinogen into Adult Treatment Panel III criteria identified an additional 16\% to 20\% of individuals as having MetS, and both C-reactive protein-MetS and fibrinogen-MetS were associated with incident low ABI (risk ratio, 1.36; 95\% CI, 1.07-1.72 and risk ratio, 1.43; 95\% CI, 1.13-1.81, respectively) and clinical PAD (hazard ratio, 1.56; 95\% CI, 1.17-2.08 and hazard ratio, 1.55; 95\% CI, 1.17-2.07, respectively). Among Adult Treatment Panel III MetS criteria, risk of PAD was most strongly associated with hypertension.

}, keywords = {Aged, Ankle Brachial Index, C-Reactive Protein, Female, Fibrinogen, Follow-Up Studies, Humans, Incidence, Longitudinal Studies, Male, Metabolic Syndrome, Peripheral Arterial Disease, Prevalence, Risk Factors, Vasculitis}, issn = {1524-4563}, doi = {10.1161/HYPERTENSIONAHA.113.01925}, author = {Garg, Parveen K and Biggs, Mary L and Carnethon, Mercedes and Ix, Joachim H and Criqui, Michael H and Britton, Kathryn A and Djouss{\'e}, Luc and Sutton-Tyrrell, Kim and Newman, Anne B and Cushman, Mary and Mukamal, Kenneth J} } @article {6363, title = {Prognostic implications of microvascular and macrovascular abnormalities in older adults: cardiovascular health study.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {69}, year = {2014}, month = {2014 Dec}, pages = {1495-502}, abstract = {

BACKGROUND: Microvascular and macrovascular abnormalities are frequently found on noninvasive tests performed in older adults. Their prognostic implications on disability and life expectancy have not been collectively assessed.

METHODS: This prospective study included 2,452 adults (mean age: 79.5 years) with available measures of microvascular (brain, retina, kidney) and macrovascular abnormalities (brain, carotid, coronary, peripheral artery) in the Cardiovascular Health Study. The burden of microvascular and macrovascular abnormalities was examined in relation to total, activity-of-daily-living disability-free, and severe disability-free life expectancies in the next 10 years (1999-2009).

RESULTS: At 75 years, individuals with low burden of both abnormalities lived, on average, 8.71 years (95\% confidence interval: 8.29, 9.12) of which 7.67 years (7.16, 8.17) were without disability. In comparison, individuals with high burden of both abnormalities had shortest total life expectancy (6.95 years [6.52, 7.37]; p < .001) and disability-free life expectancy (5.60 years [5.10, 6.11]; p < .001). Although total life expectancy was similarly reduced for those with high burden of either type of abnormalities (microvascular: 7.96 years [7.50, 8.42] vs macrovascular: 8.25 years [7.80, 8.70]; p = .10), microvascular abnormalities seemed to have larger impact than macrovascular abnormalities on disability-free life expectancy (6.45 years [5.90, 6.99] vs 6.96 years [6.43, 7.48]; p = .016). These results were consistent for severe disability-free life expectancy and in individuals without clinical cardiovascular disease.

CONCLUSIONS: Considering both microvascular and macrovascular abnormalities from multiple noninvasive tests may provide additional prognostic information on how older adults spend their remaining life. Optimal clinical use of this information remains to be determined.

}, keywords = {Aged, Aged, 80 and over, Aging, Ankle Brachial Index, Disability Evaluation, Electrocardiography, Female, Follow-Up Studies, Forecasting, Humans, Life Expectancy, Magnetic Resonance Imaging, Male, Microcirculation, Prognosis, Prospective Studies, Risk Factors, Vascular Malformations}, issn = {1758-535X}, doi = {10.1093/gerona/glu074}, author = {Kim, Dae Hyun and Grodstein, Francine and Newman, Anne B and Chaves, Paulo H M and Odden, Michelle C and Klein, Ronald and Sarnak, Mark J and Patel, Kushang V and Lipsitz, Lewis A} } @article {6665, title = {Fibrosis-related biomarkers and large and small vessel disease: the Cardiovascular Health Study.}, journal = {Atherosclerosis}, volume = {239}, year = {2015}, month = {2015 Apr}, pages = {539-46}, abstract = {

OBJECTIVE: Fibrosis has been implicated in a number of pathological, organ-based conditions of the liver, kidney, heart, and lungs. The objective of this study was to determine whether biomarkers of fibrosis are associated with vascular disease in the large and/or small vessels.

METHODS: We evaluated the associations of two circulating biomarkers of fibrosis, transforming growth factor-β (TGF-β) and procollagen type III N-terminal propeptide (PIIINP), with incident peripheral artery disease (PAD) and subclinical macrovascular (carotid intima-media thickness, flow-mediated vasodilation, ankle-brachial index, retinal vein diameter), and microvascular (retinal artery diameter and retinopathy) disease among older adults in the Cardiovascular Health Study. We measured TGF-β and PIIINP from samples collected in 1996 and ascertained clinical PAD through 2011. Measurements of large and small vessels were collected between 1996 and 1998.

RESULTS: After adjustment for sociodemographic, clinical, and biochemical risk factors, TGF-β was associated with incident PAD (hazard ratio [HR]~=~1.36 per doubling of TGF-β, 95\% confidence interval [CI]~=~1.04, 1.78) and retinal venular diameter (1.63~μm per doubling of TGF-β, CI~=~0.23, 3.02). PIIINP was not associated with incident PAD, but was associated with carotid intima-media thickness (0.102~mm per doubling of PIIINP, CI~=~0.029, 0.174) and impaired brachial artery reactivity (-0.20\% change per doubling of PIIINP, CI~=~-0.39,~-0.02). Neither TGF-β nor PIIINP were associated with retinal arteriolar diameter or retinopathy.

CONCLUSIONS: Serum concentrations of fibrosis-related biomarkers were associated with several measures of large vessel disease, including incident PAD, but not with small vessel disease. Fibrosis may contribute to large vessel atherosclerosis in older adults.

}, keywords = {Aged, Ankle Brachial Index, Biomarkers, Brachial Artery, Carotid Artery Diseases, Carotid Intima-Media Thickness, Cross-Sectional Studies, Female, Fibrosis, Humans, Incidence, Male, Peptide Fragments, Peripheral Arterial Disease, Predictive Value of Tests, Procollagen, Prognosis, Prospective Studies, Retinal Diseases, Risk Factors, Transforming Growth Factor beta, United States, Vasodilation}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2015.02.020}, author = {Agarwal, Isha and Arnold, Alice and Glazer, Nicole L and Barasch, Eddy and Djouss{\'e}, Luc and Fitzpatrick, Annette L and Gottdiener, John S and Ix, Joachim H and Jensen, Richard A and Kizer, Jorge R and Rimm, Eric B and Siscovick, David S and Tracy, Russell P and Wong, Tien Y and Mukamal, Kenneth J} } @article {6996, title = {Lipoprotein-Associated Phospholipase A2 and Incident Peripheral Arterial Disease in Older Adults: The Cardiovascular Health Study.}, journal = {Arterioscler Thromb Vasc Biol}, volume = {36}, year = {2016}, month = {2016 Apr}, pages = {750-6}, abstract = {

OBJECTIVE: Although prior studies report a relationship between elevated lipoprotein-associated phospholipase A2 (Lp-PLA2) and incident cardiovascular disease, the prospective association of Lp-PLA2 with incident peripheral arterial disease (PAD) has not been studied. We investigated the association between Lp-PLA2 mass and activity and the risk of developing clinical PAD and low ankle-brachial index (ABI).

APPROACH AND RESULTS: Among Cardiovascular Health Study participants, a population-based cohort of 5888 adults aged >=65 years enrolled in 1989 to 1990, Lp-PLA2 mass and activity were measured in 4537 individuals without baseline PAD. Clinical PAD, defined as leg artery revascularization or diagnosed claudication, was ascertained through 2011. Incident low ABI, defined as ABI <0.9 and decline of >=0.15, was assessed among 3537 individuals who had an ABI >0.9 at baseline and a second ABI measurement 3 or 6 years later. Analyses were adjusted for demographics, cholesterol, smoking, comorbidities, and C-reactive protein. Each standard deviation increment in Lp-PLA2 mass (117 ng/mL) was associated with a higher risk of developing clinical PAD (hazard ratio 1.28; 95\% confidence interval 1.13, 1.45) and incident low ABI (odds ratio 1.16; 95\% confidence interval 1.00, 1.33). Results per standard deviation increment in Lp-PLA2 activity (13 nmol/min per mL) were similar for clinical PAD (hazard ratio 1.24; 95\% confidence interval 1.07, 1.44) and low ABI (odds ratio 1.28; 95\% confidence interval 1.09, 1.50).

CONCLUSIONS: Higher Lp-PLA2 mass and activity were associated with development of both incident clinical PAD and low ABI. Future studies are needed to determine whether pharmacological inhibition of Lp-PLA2 reduces the incidence of PAD.

}, keywords = {1-Alkyl-2-acetylglycerophosphocholine Esterase, Age Factors, Aged, Aging, Ankle Brachial Index, Biomarkers, Chi-Square Distribution, Female, Humans, Incidence, Inflammation Mediators, Logistic Models, Male, Odds Ratio, Peripheral Arterial Disease, Prognosis, Proportional Hazards Models, Risk Assessment, Risk Factors, Time Factors, United States, Up-Regulation}, issn = {1524-4636}, doi = {10.1161/ATVBAHA.115.306647}, author = {Garg, Parveen K and Arnold, Alice M and Hinckley Stukovsky, Karen D and Koro, Carol and Jenny, Nancy S and Mukamal, Kenneth J and Criqui, Michael H and Furberg, Curt D and Newman, Anne B and Cushman, Mary} }