Citations

Study Design: This was a retrospective cohort study. Objective: The objective of this study was to quantify the rates of complication following surgical treatment for symptomatic degenerative and isthmic spondylolisthesis and to examine the association between slip reduction and complication rates. Summary of Background Data: It is unclear if the degree of spondylolisthesis reduction during lumbar spine fusion in adults influences the rate of surgical complications. Methods: This is a retrospective cohort study of 1-level and 2-level adult fusion patients with degenerative or isthmic spondylolisthesis. The degree of reduction and complications were calculated, and complication rates between those with and without reduction were compared. Results: The surgical reduction was improved by 1 Meyerding grade in 56.5% of the 140 patients included in this analysis. Of those patients, 60% had a grade 1 spondylolisthesis. In addition, 62.5% of grade 2 slips had an improvement by 1 grade. Surgical reduction during lumbar fusion did not result in a higher rate of complications compared with in situ fusion. Conclusions: During 1-level or 2-level lumbar fusion for degenerative or isthmic spondylolisthesis, a 1-grade reduction of the slip was achieved in 56% of patients in this retrospective case series. Reduction of the spondylolisthesis was not associated with a higher rate of complication when compared with in situ fusion. Level of Evidence: Level IV.

Background: Considerable disagreement exists among experts regarding the appropriate extent of diagnostic testing after ischemic stroke (IS). Evidence-based data guiding stroke evaluation for individual patients according to the underlying phenotype are unknown. We sought to determine the yield of cardiac and arterial evaluations for identifying an alternative major stroke etiology in patients with a given phenotype in the NINDS Stroke Genetics Network (SiGN). Methods: SiGN is a consortium of IS studies at 22 US and European sites aiming to identify stroke susceptibility genes. Adjudicators certified in Causative Classification of Stroke (CCS) system determined major etiologic stroke phenotypes based on chart review. All diagnostic data entered into the CCS software were stored in a confidential database. We determined the probability of identifying an alternative major abnormality based on cardiac (history, EKG, echocardiography) and arterial [intracranial (IC), extracranial (EC)] evaluations in 3 stroke phenotypes: lacunar infarct (LI), large artery atherosclerosis (LAA), and cardiac embolism (CE). Proportions of alternative major etiologies were calculated in patients with complete evaluations in each phenotype. Results: The analyses included 15720 patients. Among these, 2299 had phenotypic subtype of LI (1660 with cardiac and 1691 with arterial evaluations); 4228 had CE (2451 with arterial evaluation); and 2613 had LAA (2047 with cardiac evaluation). Cardiac evaluation revealed a major cardiac source of embolism in 12.3% of patients with LI and 20.3% with LAA. Echocardiography demonstrated an additional major structural cardiac source not seen by history/examination/EKG in 1.9% and 1.6% in LI and LAA respectively. Arterial evaluation led to the identification of ≥50%ipsilateral stenosis in 13.5% (IC: 8.9%, EC: 5.8%) of patients with LI and 17% (IC: 8.1%, EC: 11.3%) of those with CE. In LI patients with complete cardiac and vascular evaluations, 24.1% had an alternative major stroke etiology. Conclusions: A considerable proportion of IS patients with LI, LAA, and CE harbor an alternative major etiology. In the future, these results can be used to generate evidence-based and cost-effective evaluation and management strategies.

Several loci have been discovered and replicated for urine albumin-creatinine ratio (ACR), a measure of kidney function, in European populations; however, other ethnic populations such as African-Americans have been less studied for this trait. We examined the association of genetic variants on the Metabochip with natural log transformed ACR (ln(ACR)) in 4,629 African-Americans from the Population Architecture using Genomics and Epidemiology (PAGE) Study which includes participants from the Atherosclerosis Risk in Communities (ARIC), Cardiovascular Health Study (CHS), Coronary Artery Risk Development in Young Adults (CARDIA), and Epidemiologic Architecture for Genes Linked to the Environment (EAGLE-BioVU) studies. We then replicated our findings in 1,533 African-American participants from the Multi-Ethnic Study of Atherosclerosis (MESA). Linear regression models were used to examine associations, assuming additive effects of the SNPs. Within each study, models were adjusted for age, field center (where applicable), and principal components of ancestry, and stratified by sex. Fixed effects inverse variance weighted meta-analysis was used to combine results from contributing studies. Array-wide statistical significance was concluded for SNP associations of p-value less than 2.8 x 10-7. Mean ln(ACR) ranged from 1.4 to 2.9 mg/g, average age ranged from 44 to 77 years, and percent female participants ranged from 59-65% in the contributing studies. Four SNPs were significantly associated array-wide with ACR in the discovery sample: rs17399841 in GRHL2 (β=-0.67, MAF=0.01, p=2.7x10-9), rs153914 near SPATA9/RHOBTB3 (β=-0.59, MAF=0.01, p=1.0x10-7), rs17439845 in LEF1 (β=-0.49, MAF=0.02, p=1.3x10-7), and rs11836243 near ZNF641/ANP32D (β=0.23, MAF=0.12, p=1.8x10-7). Of these four loci, only the association of rs17439845 with ACR replicated in MESA (β=-0.36, p=0.038), with a combined discovery-replication beta of -0.46 and p value of 1.8x10-8. Combined discovery-replication for rs17399841, rs153914, and rs11836243 no longer achieved array-wide significance (p-values 9.84x10-7, 1.98x10-5, and 1.32x10-4, respectively). LEF1 is a mediator in the Wnt signaling pathway, and has been previously implicated in systemic lupus erythematosus and osteoporosis, as well as previously associated with waist circumference, echocardiographic traits, bone mineral density, and blood count traits. Continuing studies in diverse populations are warranted to identify a set of loci important in contributing to the variation in ACR.

Introduction: Among older adults with diabetes, cognitive dysfunction is of particular concern as it has implications for treatment adherence and diabetes self-management. The prevalence of cognitive dysfunction has not been well characterized in this population. Methods: We conducted a cross-sectional analysis of 5509 participants (1815 with diabetes) from visit 5 (2011-2013) of the ARIC Study. Diabetes was defined based on self-reported physician diagnosis, diabetes medication use, or HbA1c ≥ 6.5%. Cognitive function was measured using 8 neuropsychological tests, which were grouped into three cognitive domains representing memory, executive function, and language. Participants were categorized as having cognitive dysfunction if test scores were more than 1.5 standard deviations below age-, race-, and education-adjusted scores derived from a cognitively healthy population. We calculated crude prevalence estimates and used Poisson regression to estimate adjusted prevalence ratios (PRs), comparing cognitive dysfunction in persons with and without diabetes. We adjusted for demographic and clinical characteristics. Results: The mean age of participants was 75 years, 59% were female, 79% were white, and 33% had diabetes. In each domain, the prevalence of cognitive dysfunction among persons with diabetes ranged from 14% to 27%. Persons with diabetes were more likely than persons without diabetes to have dysfunction in multiple domains (PR = 1.29, 95% CI: 1.12, 1.49). Prevalence of cognitive dysfunction was significantly higher in persons with versus without diabetes for memory (PR=1.13, 95% CI: 1.02, 1.25), language (PR=1.24, 95% CI: 1.09, 1.45), and executive function (PR=1.10, 95% CI: 1.00, 1.22)(Figure). PRs were similar in crude models. Conclusions: The prevalence of cognitive dysfunction among older adults with diabetes is high. These results have implications for how physicians educate patients in appropriate self-management practices and for the prevention of diabetes-related complications.

Introduction: Increased levels of hepatocyte growth factor (HGF), active in cell growth, motility, and morphogenesis, are associated with the presence of obesity, poor metabolic health, and cardiovascular disease. Hypothesis: We assessed the hypothesis that higher baseline levels of HGF will be associated with increased risk of diabetes. Methods: We examined the association between HGF and incident diabetes in MESA, including 5395 men and women 45-84 years of age at enrollment (2000-02). Fasting serum HGF was measured at baseline and on a subsample of participants at exam 2 (n = 1915). From 2000-11, incidence of diabetes was ascertained over 4 follow-up examinations, determined by new use of insulin or oral hypoglycemic medication or fasting glucose ≥ 126 mg/dL. Cox regression was used to estimate hazard ratios (HR) for incident diabetes according to 1 standard deviation unit (SDU) of HGF (1 SDU =256 pg/mL), before and after adjustment for age, sex, race/ethnicity, education, study center, smoking status, alcohol consumption, BMI, WC, fasting glucose and insulin, CRP, and IL-6 levels. Similarly, hazard ratios for incident diabetes were estimated according to change in HGF levels from exam 1 to exam 2 in the subsample. Results: At baseline, older age, male sex, current smoking, and higher body mass index (BMI), waist circumference (WC), fasting glucose and insulin, C-reactive protein (CRP) and interleukin-6 (IL-6) levels were all associated with higher levels of HGF, while greater education and physical activity were associated with lower serum HGF. Incidence of diabetes in this analytic sample was 12% (n cases = 670). Per 1 SDU increase in baseline HGF level, unadjusted risk for diabetes increased 1.46 fold (95% CI=1.37, 1.56). After adjustment, diabetes risk per 1 SDU increase in HGF was attenuated but remained significantly increased (HR=1.22; 95% CI=1.12, 1.32). No association was found between change in HGF level between exam 1 and exam 2 and incidence of diabetes. There was no evidence of effect modification by race/ethnicity for either analysis. Conclusion: In conclusion, in this ethnically diverse U.S. adult population, higher levels of serum HGF were independently associated with increased incidence of diabetes.

Background: Given the global burden of peripheral arterial disease (PAD) and the associated morbidity, continuing investigation of potential biomarkers as therapeutic targets for preventing PAD is warranted. The association of P-selectin, an endothelial cell adhesion molecule, with the ankle brachial index (ABI) and PAD is not well established. Thus, we examined the association of circulating P-selectin with prevalent and incident PAD, the ABI, and change in the ABI. Methods: The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective population-based cohort including 6814 non-Hispanic white, African American, Hispanic and Chinese men and women aged 45-84 at baseline (2000-02). For this analysis, 5700 participants with both P-selectin at Exam 2 (2002-04) and the ABI at Exam 3 (2004-05) were available, with change in ABI from Exam 3 to Exam 5 (2010-12) available on 4276 participants. P-selectin was modeled per standard deviation (SD), while prevalent and incident PAD were defined as ABI ≤ 0.90 after excluding those with ABI>1.4. Linear regression was used for ABI, growth curve models for change in ABI, and logistic regression for prevalent and incident PAD. Results: In models adjusted for demographics, lifestyle factors, comorbidities, blood pressure, lipids, fasting glucose, c-reactive protein (CRP), interleukin-6 (IL-6), D-dimer, and fibrinogen, each SD (13 ng/mL) higher P-selectin was significantly associated with 0.007 lower ABI (95% CI ((-0.011, -0.004)), p<0.001), and an average change in the ABI of -0.006 ((-0.010, -0.003, p<0.001). P-selectin was also significantly associated with a 1.14-fold greater odds of prevalent PAD ((1.00, 1.28), p=0.04), and a 1.30-fold greater odds of incident PAD ((1.10, 1.55), p<0.001). There were no significant interactions of p-selectin by race/ethnicity or gender. Addition of P-selectin to models containing traditional PAD risk factors as well as CRP, IL-6, D-dimer and fibrinogen did not improve the c-statistic or net reclassification for incident PAD. Conclusions: P-selectin appears to be strongly associated with the development of PAD. However, further research is needed in population-based studies to confirm prospective associations of p-selectin with incident PAD and change in the ABI.

PR interval (PR) prolongation is a predictor of atrial fibrillation, a common cardiac arrhythmia, and is an established risk factor for pacemaker implantation, heart failure, stroke, and all-cause mortality. Previous genome-wide association studies in European (EU) and African (AA) descent populations have identified multiple loci associated with PR. However, it is unclear whether these loci are relevant in other racial groups, including Hispanic/Latinos (HL). Extending studies to include admixed populations such as HL also provides the potential to narrow regions associated with PR and identify population specific variants. Therefore, we evaluated 1,135 SNPs from four previously identified PR loci ( SCN5A, SCN10A, CAV1-CAV2, and TBX5-TBX3 ), fine-mapped on the Illumina Metabochip for association with PR. Associations were examined using linear regression assuming an additive genetic model and adjusting for global ancestry and clinical covariates (age, sex, RR interval, body mass index, height, systolic blood pressure) in 11,800 HL participants from participating studies of the Population Architecture using Genomics and Epidemiology (PAGE) consortia. Three of the four loci ( SCN5A, SCN10A, and CAV1-CAV2 ) generalized to HL populations ( P <7.1E-4 based on the number of SNPs correlated at r 2 >0.2 with EU-identified index SNPs). At each of these loci, we identified SNPs with stronger evidence of association with PR than the EU-identified index SNP when examined in the HL population ( SCN5A : rs7374540; SCN10A : rs6801957; CAV-CAV2 : rs717957). Conditional analyses also identified two additional independent SNPs at each of the three generalized loci ( SCN5A : rs3796387, rs9861242; SCN10A : rs10428132, rs7433723; CAV1-CAV2 : rs3801995, rs3807994), representing potential secondary signals. Furthermore, linkage disequilibrium (LD) patterns in Hispanics enabled the narrowing of the regions flanking the EU-identified index SNPs. For example, at the CAV1-CAV2 locus, HL LD patterns indicated that seven SNPs were in LD with rs3807989, the EU-identified index SNP, compared to 17 SNPs that were in LD with rs3807989 when applying EU LD patterns, reducing the size of the region by 71 kilobases. Finally, we examined evidence for population specific signals outside of the specific regions identified in EU populations which were associated with PR in Hispanics by focusing on SNPs uncorrelated with the EU index signals. At all four loci, multiple SNPs had evidence of association independent of the signals examined based on EU results. In conclusion, the same genetic loci that influence PR in European descent populations are also important in Hispanic populations, although we detected evidence for population specific SNPs. These results emphasize the importance of examining genetic associations in diverse populations in order to narrow the genomic interval for future functional interrogation.

Incident hypertension varies across races/ethnicities. Mechanisms implicated in the pathogenesis are endothelial dysfunction with reduction of nitric oxide and alterations of the Renin-Angiotensin-Aldosterone System (RAAS). Stromal Derived Factor 1 (SDF1) and Transforming Growth Factor β1 (TGFβ1) are essential in these processes. SDF1 is a chemotactic protein that regulates migration of endothelial progenitor cells from the bone marrow to the arterial wall to repair endothelial damage; TGFβ1 promotes extra-cellular matrix deposition within arterial vessels, inhibits nitric oxide production and stimulates renin release. In order to investigate the association of circulating levels of these proteins with incident hypertension across different ethnicities, an ethnic stratified random sample of 2,880 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) was used. Of those, 988 participants had available plasma samples and were without hypertension, defined as blood pressure ≥ 140/90 mmHg, or current use of antihypertensive medications, at baseline. During a median follow up of 8.5 years, 388 new cases of hypertension (101 in non-Hispanic whites, 94 in Chinese, 101 in African Americans and 92 in Hispanics) were observed. Time to hypertension incidence was estimated using Cox proportional hazards regression. Hazard Ratios were adjusted for age, sex, diabetes, LDL, HDL, triglycerides, BMI, smoking status and current alcohol use. The race/ethnicity by protein interaction p-values were 0.055 and 0.066 for TGFβ1 and SDF1 respectively, suggesting heterogeneity across races/ethnicities. In Chinese, a difference of one standard deviation of plasma TGFβ1 was associated with a 22% increase in incident hypertension (HR (95% CI) 1.22 (1.02, 1.47), p-value=0.03); and a difference of one standard deviation of plasma SDF1 was associated with a 31% decrease in incident hypertension (HR (95% CI) 0.69 (0.52, 0.91), p-value 0.008). No significant association was found between these proteins and incident hypertension among non-Hispanic whites, African or Hispanic Americans. In conclusion, soluble markers of endothelial integrity and of RAAS activation were associated with the incidence of hypertension among Chinese Americans. These results suggest heterogeneity in the pathophysiology of hypertension according to race/ethnicity.

Introduction: Compared to other racial and ethnic groups, African Americans experience greater negative psychosocial factors (depression, stress), which are related to increased risk of cardiovascular disease (CVD). Little research has examined the association of positive psychosocial factors (optimism) with cardiovascular health in this population. Using the Jackson Heart Study (JHS) data, we examined the association of optimism with the American Heart Association Life’s Simple 7 TM (LS7), a measure of seven metrics that assesses a person’s cardiovascular health. Hypothesis: Higher levels of optimism are positively associated with individual LS7 metrics, and positively associated with the total LS7 score. Methods: We evaluated cross-sectional associations of optimism with each LS7 metric [cigarette smoking, physical activity, diet, body mass index (BMI), blood pressure, cholesterol, glucose] and with a composite LS7 score among 4,761 participants, 21-95 years old (women=3,070; men=1,691) enrolled in the JHS, a single-site, community-based cohort of African Americans residing in Jackson, MS. Optimism was measured in tertiles (low, moderate, high) to examine threshold effects. Each LS7 metric was classified as poor, intermediate, and ideal. LS7 metrics were also summed to create a total continuous score (0-13) categorized in tertiles (low, moderate, high). Multinomial logistic regression estimated the odds ratios (OR, 95% confidence interval-CI) of intermediate (vs. poor) and ideal (vs. poor) LS7 metric by levels of optimism. Multinomial regression also estimated the odds of moderate (vs. low) or high (vs. low) total LS7 score by optimism. Models adjusted for demographics, SES, and depressive symptoms. Results: Descriptive findings showed that participants who reported high optimism had ideal physical activity, nutrition, smoking, blood pressure, glucose and high total LS7 score (all p<0.01). After adjustment for age, sex, education, income, marital status, and insurance status, participants who reported high (vs. low) optimism had a 39% increased odds of having ideal (vs. poor) physical activity (OR 1.39; 95% CI 1.10-1.76) and a 33% increased odds of having ideal (vs. poor) smoking (OR 1.33; 95% CI 1.02-1.73). Participants who reported high (vs. low) optimism had a 34% greater odds of having a high (vs. low) total LS7 score (OR 1.34 95% CI 1.03-1.74) after full adjustment. Conclusion: Optimism is associated with ideal physical activity and ideal smoking, which is important for promoting cardiovascular health and reducing the risk of CVD among African Americans in this sample.