Silke Wiedmann

Association of common polymorphisms in GLUT9 gene with gout but not with coronary artery disease in a large case-control study.

Background Serum uric acid (UA) levels have recently been shown to be genetically influenced by common polymorphisms in the GLUT9 gene in two genome-wide association analyses of Italian and British populations. Elevated serum UA levels are often found in conjunction with the metabolic syndrome. Hyperuricemia is the major risk factor for gout and has been associated with increased cardiovascular morbidity and mortality. The aim of the present study was to further elucidate the association of polymorphisms in GLUT9 with gout and coronary artery disease (CAD) or myocardial infarction (MI). To test our hypotheses, we performed two large case-control association analyses of individuals from the German MI Family Study. Methods and Findings First, 665 patients with gout and 665 healthy controls, which were carefully matched for age and gender, were genotyped for four single nucleotide polymorphisms (SNPs) within or near the GLUT9 gene. All four SNPs demonstrated highly significant association with gout. SNP rs6855911, located within intron 7 of GLUT9, showed the strongest signal with a protective effect of the minor allele with an allelic odds ratio of 0.62 (95% confidence interval 0.52–0.75; p  =  3.2*10−7). Importantly, this finding was not influenced by adjustment for components of the metabolic syndrome or intake of diuretics. Secondly, 1,473 cases with severe CAD or MI and 1,241 healthy controls were tested for the same four GLUT9 SNPs. The analyses revealed, however, no significant association with CAD or with MI. Additional screening of genome-wide association data sets showed no signal for CAD or MI within the GLUT9 gene region. Conclusion Thus, our results provide compelling evidence that common genetic variations within the GLUT9 gene strongly influence the risk for gout but are unlikely to have a major effect on CAD or MI in a German population.

Genetic variants within the LPIN1 gene, encoding lipin, are influencing phenotypes of the metabolic syndrome in humans

OBJECTIVE— Lipin, a novel molecular protein expressed by adipocytes, has marked effects on adipose tissue mass, insulin sensitivity, and glucose homeostasis. Thus, we hypothesized that genetic variants within LPIN1 are associated with traits of the metabolic syndrome. RESEARCH DESIGN AND METHODS— A total of 15 single nucleotide polymorphisms (SNPs) covering the LPIN1 gene region were genotyped in an age- and sex-stratified sample of the general population (Monitoring Trends and Determinants on Cardiovascular Diseases Study Augsburg; DNA and phenotypes of 1,416 Caucasians). Ten SNPs were also genotyped for replication in an independent sample of 1,030 subjects recruited throughout Germany. The metabolic syndrome was defined via the sum of its core components and, additionally, by a factor score derived from factor analysis. Permutation-based methods were used to test the association between genetic LPIN1 variants and metabolic traits for empirical significance. RESULTS— Linkage disequilibrium (LD) analysis revealed three LD blocks encompassing LPIN1. We identified three associated three-marker haplotypes: one common haplotype (26.8% frequency) increases the risk for the metabolic syndrome (odds ratio 1.6 [95% CI 1.2–2.2]), while the other two, being less common (5.7 and 4.0%), are strongly associated with lower blood pressure levels (systolic blood pressure 127 ± 18 vs. 135 ± 20 mmHg; P = 0.0001), a lower BMI (24.6 ± 3.6 vs. 26.9 ± 4.1 kg/m2; P = 3.7 × 10−7) and waist circumference (82 ± 12 vs. 90 ± 12 cm; P = 3.2 × 10−8), lower A1C levels (5.1 ± 0.7 vs. 5.3 ± 0.9%; P = 0.0002), as well as a lower metabolic syndrome factor score (−0.67 ± 1.00 vs. 0.04 ± 1.24; P = 1.4 × 10−7). Furthermore, the frequencies of arterial hypertension (23.7 vs. 46.4%; P = 0.00001), obesity (12.9 vs. 30.8%; P = 0.0003), diabetes (2.2 vs. 8.2%; P = 0.041), and the presence of three or more metabolic syndrome components (3.3 vs. 13.7%; P = 0.002) were significantly lower than in subjects not carrying one of these protective haplotypes. Strong associations were also observed in the replication sample using the same haplotypes but with effects in the opposite direction. CONCLUSIONS— These data suggest that allelic variants of the LPIN1 gene have significant effects in human metabolic traits and thus implicate lipin in the pathophysiology of the metabolic syndrome.

TeleStroke Units Serving as a Model of Care in Rural Areas: 10-Year Experience of the TeleMedical Project for Integrative Stroke Care

Background and Purpose— Stroke Unit care improves stroke prognosis and is recommended for all patients with stroke. In rural areas, population-wide implementation of Stroke Units is challenging. Therefore, the TeleMedical Project for integrative Stroke Care (TEMPiS) was established in 2003 as a TeleStroke Unit network to overcome this barrier in Southeast Bavaria/Germany. Evaluation of its implementation between 2003 and 2005 had revealed improved process quality and clinical outcomes compared with matched hospitals without TeleStroke Units. Data on sustainability of these effects are lacking. Methods— Effects on the stroke care of the local population were analyzed by using data from official hospital reports. Prospective registries from 2003 to 2012 describe processes and outcomes of consecutive patients with stroke and transient ischemic attack treated in TEMPiS hospitals. Quality indicators assess diagnostics, treatment, and outcome. Rates and timeliness of intravenous thrombolysis as well as data on teleconsultations and secondary interhospital transfers were reported over time. Results— Within the covered area, network implementation increased the number of patients with stroke and transient ischemic attack treated in hospitals with (Tele-)Stroke Units substantially from 19% to 78%. Between February 2003 and December 2012, 54 804 strokes and transient ischemic attacks were treated in 15 regional hospitals, and 31 864 teleconsultations were performed. Intravenous thrombolysis was applied 3331 stroke cases with proportions increasing from 2.6% to 15.5% of all patients with ischemic stroke. Median onset-to-treatment times decreased from 150 (interquartile range, 127–163) to 120 minutes (interquartile range, 90–160) and door-to-needle times from 80 (interquartile range, 68–101) to 40 minutes (interquartile range, 29–59). Conclusions— TeleStroke Units can provide sustained high-quality stroke care in rural areas.

Variations in quality indicators of acute stroke care in 6 European countries: the European Implementation Score (EIS) Collaboration

Background and Purpose— Quality indicators serve as standards of care by which performance of individual hospitals is measured. Although several audits for monitoring quality of stroke care have been established in Europe, there is currently no consensus on quality indicators for acute stroke care or for methodology for collecting information on these measures. Methods— An up-to-date inventory on European stroke audits in place in 2006 was performed in the course of a project funded by the European Union (European Implementation Score Collaboration [EIS]). Two regional (Flanders, Belgium; Catalonia, Spain) and 4 national (Germany, Scotland, Sweden, England/Wales/Northern Ireland) stroke audits took part. Between November 2009 and July 2010, 2 standardized surveys and a series of interviews were performed to determine characteristics, methods, and content of these quality initiatives. For quality purposes, all summarized information was validated by representatives of the respective audits. Results— Overall, 123 quality indicators (91 process, 24 outcome, and 8 structural indicators) were identified. Anticoagulants in patients with atrial fibrillation and brain imaging were the only quality indicators used in all, whereas another 13 indicators were used in at least 2 of the quality initiatives. Substantial variations were found across the audits in terms of the development process of quality indicators, inclusion criteria, participation, population coverage, data documentation, follow-ups, benchmarking, and feedback of results to participants. Conclusions— There is a huge variety in measuring performance of acute stroke care in Europe, hampering valid comparisons of acute stroke care. Common standards for defining quality indicators and collecting information required for these measures should be defined in Europe.

The common Y402H variant in complement factor H gene is not associated with susceptibility to myocardial infarction and its related risk factors

Recently, the genetic variant Y402H in the CFH (complement factor H) gene was associated with an increased risk for MI (myocardial infarction) in a prospective Caucasian cohort. In another nested case-control study, however, the CFH-Y402H variant did not carry susceptibility to MI. The aim of the present study was to test for an association between the CFH-Y402H variant and MI in a large case-control sample with a familial background for CAD (coronary artery disease). A total of 2161 individuals from the German MI family study were studied by questionnaire, physical examination and biochemical analyses. MI patients (n=1188; 51.4+/-8.6 years at first MI) were recruited from families with at least two members affected by MI and/or severe CAD. Spouses, sisters-in-law and brothers-in-law respectively, without MI/CAD were included as unaffected controls (n=973; 56.9+/-9.8 years). Genotyping was performed using a TaqMan assay. The common Y402H variant in the CFH gene was not associated with classical cardiovascular risk factors (diabetes, hypercholesterolaemia, hypertension, obesity, smoking and C-reactive protein serum levels). No association was found between the CFH-Y402H variant and susceptibility to MI. Separate analyses in both men and women revealed no gender-specific influence of the gene variant on cardiovascular risk factors or MI. This investigation was unable to replicate the association between the common CFH-Y402H variant and susceptibility to MI in our large Caucasian population which is enriched for genetic factors. We conclude that the CFH-Y402H variant has no relevant risk-modifying effect in our population.

The quality of acute stroke care- an analysis of evidence-based indicators in 260 000 patients.

BACKGROUND Stroke patients should be cared for in accordance with evidence-based guidelines. The extent of implementation of guidelines for the acute care of stroke patients in Germany has been unclear to date. METHODS The regional quality assurance projects that cooperate in the framework of the German Stroke Registers Study Group (Arbeitsgemeinschaft Deutscher Schlaganfall-Register, ADSR) collected data on the care of stroke patients in 627 hospitals in 2012. The quality of the acute hospital care of patients with stroke or transient ischemic attack (TIA) was assessed on the basis of 15 standardized, evidence-based quality indicators and compared across the nine participating regional quality assurance projects. RESULTS Data were obtained on more than 260 000 patients nationwide. Intravenous thrombolysis was performed in 59.7% of eligible ischemic stroke patients patients (range among participating projects, 49.7-63.6%). Dysphagia screening was documented in 86.2% (range, 74.8-93.1%). For the following indicators, the defined targets were not reached for all of Germany: anti-aggregation within 48 hours, 93.4% (range, 86.6-96.4%); anticoagulation for atrial fibrillation, 77.6% (range, 72.4-80.1%); standardized dysphagia screening, 86.2% (range, 74.8-93.1%); oral and written information of the patients or their relatives, 86.1% (range, 75.4-91.5%). The rate of patients examined or treated by a speech therapist was in the target range. CONCLUSION The defined targets were reached for most of the quality indicators. Some indicators, however, varied widely across regional quality assurance projects. This implies that the standardization of care for stroke patients in Germany has not yet been fully achieved.

Variations in acute hospital stroke care and factors influencing adherence to quality indicators in 6 European audits.

Background and Purpose— We compared compliance with standards of acute stroke care between 6 European audits and identified factors associated with delivery of appropriate care. Methods— Data were derived from stroke audits in Germany, Poland, Scotland, Catalonia, Sweden, and England/Wales/Northern-Ireland participating within the European Implementation Score (EIS) collaboration. Associations between demographic and clinical characteristics with adherence to predefined quality indicators were investigated by hierarchical logistic regression analyses. Results— In 2007/2008 data from 329 122 patients with stroke were documented. Substantial variations in adherence to quality indicators were found; older age was associated with a lower probability of receiving thrombolytic therapy, anticoagulant therapy, or stroke unit treatment and a higher probability of being tested for dysphagia. Women were less likely to receive anticoagulant or antiplatelet therapy or stroke unit treatment. No major weekend effect was found. Conclusions— Detected variations in performance of acute stroke services were found. Differences in adherence to quality indicators might indicate population subgroups with specific needs for improving care delivery.

Lack of association between a common polymorphism near the INSIG2 gene and BMI, myocardial infarction, and cardiovascular risk factors.

Epidemiological studies revealed an increasing prevalence of and a steep increase in obesity, a risk factor for cardiovascular disease. Because significant influence of a polymorphism, rs7566605, near the INSIG2 gene on BMI has been shown in the general population and in obesity cohorts, we hypothesized that this polymorphism might also act through an elevated BMI on the development of coronary artery disease (CAD) or myocardial infarction (MI). We pursued two strategies: First, the polymorphism rs7566605 was investigated for association with BMI, CAD/MI, and cardiovascular risk factors in a large German cohort at high risk for CAD and MI (n = 1,460 MI patients) as compared to unrelated healthy controls (n = 1,215); second, we extended our analyses on the families of MI patients and performed family‐based association testing (n = 5,390 individuals). The polymorphism rs7566605 was analyzed using TaqMan technology. No deviation from Hardy–Weinberg equilibrium could be observed, and the call rate was 98.2%. No significant associations of rs7566605 with CAD/MI, BMI, and classical cardiovascular risk factors could be detected in the full sample size or in the subgroups. A total of 6,878 individuals were investigated in a population of German MI patients and their family members. Although the number of individuals was large enough, no influence of the rs7566605 INSIG2 polymorphism was detected on BMI and CAD/MI. We therefore conclude that in our sample the SNP rs7566605 near the INSIG2 gene does not influence BMI and is not associated directly with CAD/MI or indirectly through cardiovascular risk factors.

Association between PPARalpha gene polymorphisms and myocardial infarction.

PPARalpha (peroxisome-proliferator-activated receptor alpha) regulates the expression of genes that are involved in lipid metabolism, tissue homoeostasis and inflammation. Consistent rodent and human studies suggest a link between PPARalpha function and cardiovascular disease, qualifying PPARalpha [PPARA in HUGO (Human Genome Organisation) gene nomenclature] as a candidate gene for coronary artery disease. In the present study, we comprehensively evaluated common genetic variations within the PPARalpha gene and assessed their association with myocardial infarction. First, we characterized the linkage disequilibrium within the PPARalpha gene in an initial case-control sample of 806 individuals from the Regensburg Myocardial Infarction Family Study using a panel of densely spaced SNPs (single nucleotide polymorphisms) across the gene. Single SNP analysis showed significant association with the disease phenotype [OR (odds ratio)=0.74, P=0.012, 95% CI (confidence interval)=0.61-0.94 for rs135551]. Moreover, we identified a protective three-marker haplotype with an association trend for myocardial infarction (OR=0.76, P=0.067, 95% CI=0.56-1.02). Subsequently, we were able to confirm the single SNP and haplotype association results in an independent second case-control cohort with 667 cases from the Regensburg Myocardial Infarction Family Study and 862 control individuals from the WHO (World Health Organization) MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) Augsburg project (OR=0.87, P=0.046, 95% CI=0.72-0.99 for rs135551 and OR=0.80, P=0.034, 95% CI=0.65-0.98 for the three-marker haplotype respectively). From these cross-sectional association results, we provide evidence that common variations in the PPARalpha gene may influence the risk of myocardial infarction in a European population.

Time Trends in Incidence of Pathological and Etiological Stroke Subtypes during 16 Years: The Erlangen Stroke Project

Background: Population-based data, which continuously monitors time trends in stroke epidemiology are limited. We investigated the incidence of pathological and etiological stroke subtypes over a 16 year time period. Methods: Data were collected within the Erlangen Stroke Project (ESPro), a prospective, population-based stroke register in Germany covering a total study population of 105,164 inhabitants (2010). Etiology of ischemic stroke was classified according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Results: Between January 1995 and December 2010, 3,243 patients with first-ever stroke were documented. The median age was 75 and 55% were females. The total stroke incidence decreased over the 16 year study period in men (Incidence Rate Ratio 1995-1996 vs. 2009-2010 (IRR) 0.78; 95% CI 0.58-0.90) but not in women. Among stroke subtypes, a decrease in ischemic stroke incidence (IRR 0.73; 95% CI 0.57-0.93) and of large artery atherosclerotic stroke (IRR 0.27; 95% CI 0.12-0.59) was found in men and an increase of stroke due to small artery occlusion in women (IRR 2.33; 95% CI 1.39-3.90). Conclusions: Variations in time trends of pathological and etiological stroke subtypes were found between men and women that might be linked to gender differences in the development of major vascular risk factors in the study population.