Bielinski, Suzette J.

ObjectiveAt the cellular level, how excess adiposity promotes atherogenesis is not fully understood. One pathway involves secretion of adipokines that stimulate endothelial dysfunction through increased expression of adhesion molecules. However, the relationship of adiposity to adhesion molecules that promote atherosclerosis is largely unknown.MethodsLinear regression models were used to assess the sex‐specific associations of soluble cellular adhesion molecules (sP‐ and sL‐selectin, sICAM‐1, sVCAM‐1, and sHGF) and adiposity in 5,974 adults examined as part of the Multi‐Ethnic Study of Atherosclerosis (MESA). Adiposity measures included body mass index (BMI), waist‐to‐hip‐ratio (WHR), and computed tomography measures of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT).ResultsThe mean age was 64 years and 52% were female. In multivariable models adjusting for traditional cardiovascular risk factors, sHGF was positively associated with BMI, WHR, and VAT in both males and females, and sP‐selectin with WHR and VAT in males. sVCAM‐1 was inversely associated with VAT in females only.ConclusionsOur results showed the relation of adiposity to soluble cellular adhesion proteins was similar across adiposity measures and for both sexes. However, the relationship between adiposity and sVCAM‐1 and P‐selectin may be modified by sex and the measure used to assess adiposity.

Background Socioeconomic status (SES) is an important predictor for outcomes of chronic diseases. However, it is often unavailable in clinical data. We sought to determine whether an individual housing-based SES index termed HOUSES can influence the likelihood of multiple chronic conditions (MCC) and hospitalisation in a community population. Methods Participants were residents of Olmsted County, Minnesota, aged >18 years, who were enrolled in Mayo Clinic Biobank on 31 December 2010, with follow-up until 31 December 2011. Primary outcome was all-cause hospitalisation over 1 calendar-year. Secondary outcome was MCC determined through a Minnesota Medical Tiering score. A logistic regression model was used to assess the association of HOUSES with the Minnesota tiering score. With adjustment for age, sex and MCC, the association of HOUSES with hospitalisation risk was tested using the Cox proportional hazards model. Results Eligible patients totalled 6402 persons (median age, 57 years; 25th–75th quartiles, 45–68 years). The lowest quartile of HOUSES was associated with a higher Minnesota tiering score after adjustment for age and sex (OR (95% CI) 2.4 (2.0 to 3.1)) when compared with the highest HOUSES quartile. Patients in the lowest HOUSES quartile had higher risk of all-cause hospitalisation (age, sex, MCC-adjusted HR (95% CI) 1.53 (1.18 to 1.98)) compared with those in the highest quartile. Conclusions Low SES, as assessed by HOUSES, was associated with increased risk of hospitalisation and greater MCC health burden. HOUSES may be a clinically useful surrogate for SES to assess risk stratification for patient care and clinical research.

SummaryHepatocyte growth factor (HGF) is a mesenchyme‐derived pleiotropic factor that regulates cell growth, motility, mitogenesis, and morphogenesis in a variety of cells, and increased serum levels of HGF have been linked to a number of clinical and subclinical cardiovascular disease phenotypes. However, little is currently known regarding which genetic factors influence HGF levels, despite evidence of substantial genetic contributions to HGF variation. Based upon ethnicity‐stratified single‐variant association analysis and trans‐ethnic meta‐analysis of 6201 participants of the Multi‐Ethnic Study of Atherosclerosis (MESA), we discovered five statistically significant common and low‐frequency variants: HGF missense polymorphism rs5745687 (p.E299K) as well as four variants (rs16844364, rs4690098, rs114303452, rs3748034) within or in proximity to HGFAC. We also identified two significant ethnicity‐specific gene‐level associations (A1BG in African Americans; FASN in Chinese Americans) based upon low‐frequency/rare variants, while meta‐analysis of gene‐level results identified a significant association for HGFAC. However, identified single‐variant associations explained modest proportions of the total trait variation and were not significantly associated with coronary artery calcium or coronary heart disease. Our findings indicate that genetic factors influencing circulating HGF levels may be complex and ethnically diverse.

AbstractWe provide a mini‐review of how biobanks can support clinical genetics in the era of personalized medicine. We discuss types of biobanks, including disease specific and general biobanks not focused on one disease. We present considerations in setting up a biobank, including consenting and governance, biospecimens, risk factor and related data, informatics, and linkage to electronic health records for phenotyping. We also discuss the uses of biobanks and ongoing considerations, including genotype‐driven recruitment, investigations of gene–environment associations, and the re‐use of data generated from studies. Finally, we present a brief discussion of some of the unresolved issues, such as return of research results and sustaining biobanks over time. In summary, carefully designed biobanks can provide critical research and infrastructure support for clinical genetics in the era of personalized medicine.

AbstractBACKGROUNDSoluble intercellular adhesion molecule 1 (sICAM-1) is associated with endothelial dysfunction and clinical cardiovascular disease. We investigated the relationship of subclinical atherosclerosis with sICAM-1 concentration.METHODSsICAM-1 concentration was assayed at year 15 of the Coronary Artery Risk Development in Young Adults (CARDIA) Study (black and white men and women, average age 40 years). We assessed progression of coronary artery calcification (CAC) through year 20 (n = 2378), and both carotid artery stenosis (n = 2432) and intima-media thickness (IMT) at year 20 (n = 2240).RESULTSMedian sICAM-1 was 145.9 μg/L. Among a subgroup with advanced atherosclerotic plaque (either CAC or stenosis), IMT was 0.010 (95% CI 0.003–0.017 mm) higher per SD of sICAM-1 (44 μg/L) in a model adjusted for age, race, sex, clinic, smoking, exercise, body size, education, blood pressure, antihypertensive medication, plasma lipids, and cholesterol-lowering medication. With the same adjustment, the odds ratio (OR) for the presence of year-20 carotid artery stenosis per SD of sICAM-1 was 1.12 (95% CI 1.01–1.25, P < 0.04), whereas for occurrence of CAC progression the OR was 1.16 (1.04–1.31, P < 0.01). The associations with CAC and carotid stenosis were strongest in the top 20th of the sICAM-1 distribution.CONCLUSIONSsICAM-1 concentration may be an early biomarker that indicates changes in the artery wall that accompany atherosclerosis, as well as the presence of advanced plaque in the coronary and carotid arteries. This finding holds in people with low total burden of atherosclerosis, decades before the development of clinical CVD.

Background— Atrial fibrillation (AF) often coexists with myocardial infarction (MI), yet its prognostic influence is disputed. Prior reports studied the relationship of AF during early hospitalization for acute MI to the risk of death and could not address the timing of AF in relation to the MI (ie, before, during, after). Furthermore, as data come mostly from clinical trials, their applicability to the community is uncertain. The aims of our study were to assess the occurrence of AF among MI patients, determine whether it has changed over time, and quantify its impact and the impact of its timing on mortality after MI. Methods and Results— This was a community-based cohort of 3220 patients hospitalized with incident (first-ever) MI from 1983 to 2007 in Olmsted County, MN. Atrial fibrillation was identified by diagnostic codes and ECG. Outcomes were all-cause and cardiovascular death. Atrial fibrillation before MI was identified in 304 patients, and 729 developed AF after MI (218 [30%] within 2 days, 119 [16%] between 3 and 30 days, and 392 [54%] >30 days post-MI). The cumulative incidence of AF after MI at 5 years was 19% and did not change over the calendar year of MI (the incidence of AF was the same regardless of when the MI occurred). During a mean follow-up of 6.6 years, 1638 deaths occurred. AF was associated with an increased risk of death (hazard ratio [95% confidence interval] 3.77 [3.37 to 4.21]), independently of clinical characteristics at the time of MI and heart failure. This risk differed markedly according to the timing of AF, and was the greatest for AF occurring >30 days post MI (hazard ratio [95% confidence interval] 1.63 [1.37 to 1.93] for AF within 2 days, 1.81 [0.45 to 2.27] for AF between 3 and 30 days, and 2.58 [2.21 to 3.00] for AF >30 days post MI). Conclusions— In the community, AF is frequent in the setting of MI. Atrial fibrillation carries an excess risk of death, which is the highest for AF developing >30 days after MI.

Clinical data captured in electronic medical records accurately identify cases and controls for genome-wide association studies.

OBJECTIVE Elevated fasting glucose level is associated with increased carotid intima-media thickness (IMT), a measure of subclinical atherosclerosis. It is unclear if this association is causal. Using the principle of Mendelian randomization, we sought to explore the causal association between circulating glucose and IMT by examining the association of a genetic risk score with IMT. RESEARCH DESIGN AND METHODS The sample was drawn from the Atherosclerosis Risk in Communities (ARIC) study and included 7,260 nondiabetic Caucasian individuals with IMT measurements and relevant genotyping. Components of the fasting glucose genetic risk score (FGGRS) were selected from a fasting glucose genome-wide association study in ARIC. The score was created by combining five single nucleotide polymorphisms (SNPs) (rs780094 [GCKR], rs560887 [G6PC2], rs4607517 [GCK], rs13266634 [SLC30A8], and rs10830963 [MTNR1B]) and weighting each SNP by its strength of association with fasting glucose. IMT was measured through bilateral carotid ultrasound. Mean IMT was regressed on the FGGRS and on the component SNPs, individually. RESULTS The FGGRS was significantly associated (P = 0.009) with mean IMT. The difference in IMT predicted by a 1 SD increment in the FGGRS (0.0048 mm) was not clinically relevant but was larger than would have been predicted based on observed associations between the FFGRS, fasting glucose, and IMT. Additional adjustment for baseline measured glucose in regression models attenuated the association by about one third. CONCLUSIONS The significant association of the FGGRS with IMT suggests a possible causal association of elevated fasting glucose with atherosclerosis, although it may be that these loci influence IMT through nonglucose pathways.

We examined the association of variation in the type 2 diabetes risk-conferringTCF7L2gene with the risk of incident coronary heart disease (CHD) among the lean, overweight, and obese members of the Atherosclerosis Risk in Communities (ARIC) Study cohort. Cox proportional hazard regression analyses were performed using a general model, with the major homozygote as the reference category. For 9,865 whites, a significant increase in the risk of CHD was seen only among lean (BMI<25 kg/m2) individuals homozygous for theTallele of theTCF7L2rs7903146 gene risk variant (hazard ratio 1.42; 95% CI 1.03,1.97;P=.01). No association was found among 3,631 blacks, regardless of BMI status. An attenuated hazard ratio was observed among the nondiabetic ARIC cohort members. This study suggests that body mass modifies the association of theTCF7L2rs7903146 T allele with CHD risk.