Christian L. Roth

Diagnosis and treatment of patients with stroke in a mobile stroke unit versus in hospital: a randomised controlled trial.

BACKGROUND Only 2-5% of patients who have a stroke receive thrombolytic treatment, mainly because of delay in reaching the hospital. We aimed to assess the efficacy of a new approach of diagnosis and treatment starting at the emergency site, rather than after hospital arrival, in reducing delay in stroke therapy. METHODS We did a randomised single-centre controlled trial to compare the time from alarm (emergency call) to therapy decision between mobile stroke unit (MSU) and hospital intervention. For inclusion in our study patients needed to be aged 18-80 years and have one or more stroke symptoms that started within the previous 2·5 h. In accordance with our week-wise randomisation plan, patients received either prehospital stroke treatment in a specialised ambulance (equipped with a CT scanner, point-of-care laboratory, and telemedicine connection) or optimised conventional hospital-based stroke treatment (control group) with a 7 day follow-up. Allocation was not masked from patients and investigators. Our primary endpoint was time from alarm to therapy decision, which was analysed with the Mann-Whitney U test. Our secondary endpoints included times from alarm to end of CT and to end of laboratory analysis, number of patients receiving intravenous thrombolysis, time from alarm to intravenous thrombolysis, and neurological outcome. We also assessed safety endpoints. This study is registered with ClinicalTrials.gov, number NCT00153036. FINDINGS We stopped the trial after our planned interim analysis at 100 of 200 planned patients (53 in the prehospital stroke treatment group, 47 in the control group), because we had met our prespecified criteria for study termination. Prehospital stroke treatment reduced the median time from alarm to therapy decision substantially: 35 min (IQR 31-39) versus 76 min (63-94), p<0·0001; median difference 41 min (95% CI 36-48 min). We also detected similar gains regarding times from alarm to end of CT, and alarm to end of laboratory analysis, and to intravenous thrombolysis for eligible ischaemic stroke patients, although there was no substantial difference in number of patients who received intravenous thrombolysis or in neurological outcome. Safety endpoints seemed similar across the groups. INTERPRETATION For patients with suspected stroke, treatment by the MSU substantially reduced median time from alarm to therapy decision. The MSU strategy offers a potential solution to the medical problem of the arrival of most stroke patients at the hospital too late for treatment. FUNDING Ministry of Health of the Saarland, Germany, the Werner-Jackstädt Foundation, the Else-Kröner-Fresenius Foundation, and the Rettungsstiftung Saar.

Vitamin D deficiency in obese rats exacerbates nonalcoholic fatty liver disease and increases hepatic resistin and toll‐like receptor activation

Childhood obesity is associated with type 2 diabetes mellitus and nonalcoholic fatty liver disease (NAFLD). Recent studies have found associations between vitamin D deficiency (VDD), insulin resistance (IR), and NAFLD among overweight children. To further explore mechanisms mediating these effects, we fed young (age 25 days) Sprague‐Dawley rats with a low‐fat diet (LFD) alone or with vitamin D depletion (LFD+VDD). A second group of rats was exposed to a Westernized diet (WD: high‐fat/high‐fructose corn syrup) that is more typically consumed by overweight children, and was either replete (WD) or deficient in vitamin D (WD+VDD). Liver histology was assessed using the nonalcoholic steatohepatitis (NASH) Clinical Research Network (CRN) scoring system and expression of genes involved in inflammatory pathways were measured in liver and visceral adipose tissue after 10 weeks. In VDD groups, 25‐OH‐vitamin D levels were reduced to 29% (95% confidence interval [CI]: 23%‐36%) compared to controls. WD+VDD animals exhibited significantly greater hepatic steatosis compared to LFD groups. Lobular inflammation as well as NAFLD Activity Score (NAS) were higher in WD+VDD versus the WD group (NAS: WD+VDD 3.2 ± 0.47 versus WD 1.50 ± 0.48, P < 0.05). Hepatic messenger RNA (mRNA) levels of Toll‐like receptors (TLR)2, TLR4, and TLR9, as well as resistin, interleukins (IL)‐1β, IL‐4, and IL‐6 and oxidative stress marker heme oxygenase (HO)‐1, were higher in WD+VDD versus WD animals (P < 0.05). Logistic regression analyses showed significant associations between NAS score and liver mRNA levels of TLRs 2, 4, and 9, endotoxin receptor CD14, as well as peroxisome proliferator activated receptor (PPAR)γ, and HO‐1. Conclusion: VDD exacerbates NAFLD through TLR‐activation, possibly by way of endotoxin exposure in a WD rat model. In addition it causes IR, higher hepatic resistin gene expression, and up‐regulation of hepatic inflammatory and oxidative stress genes. (HEPATOLOGY 2012)

Fetuin-A and Its Relation to Metabolic Syndrome and Fatty Liver Disease in Obese Children Before and After Weight Loss

CONTEXT There are very limited data available concerning the relationships between fetuin-A, weight status, nonalcoholic fatty liver disease (NAFLD), and features of the metabolic syndrome (MetS) in obese humans, and especially in children. OBJECTIVE Our objective was to study the longitudinal relationships between fetuin-A, NAFLD, and MetS in obese children. DESIGN This was a 1-yr longitudinal follow-up study. SETTING This study was performed in primary care. PATIENTS A total of 36 obese and 14 lean children was included in the study. INTERVENTION An outpatient 1-yr intervention program based on exercise, behavior, and nutrition therapy was performed. MAIN OUTCOME MEASURES Changes of weight status (sd score-body mass index), waist circumference, fetuin-A, blood pressure, lipids, transaminases, insulin resistance index homeostasis model assessment (HOMA), and prevalence of NAFLD (defined by liver ultrasound) were calculated. RESULTS The 12 obese children with NAFLD had significantly higher fetuin-A levels (0.35+/-0.07 g/liter) than the 24 obese children without NAFLD (0.29+/-0.06 g/liter) and the 14 normal weight children (0.29+/-0.05 g/liter). Fetuin-A levels were independent of age, pubertal stage, and gender. Fetuin-A correlated significantly to systolic (r=0.50) and diastolic blood pressure (r=0.41), insulin resistance index HOMA (r=0.28), and high-density lipoprotein-cholesterol (r=-0.31). Changes of fetuin-A correlated significantly to changes of insulin resistance index HOMA (r=0.34), systolic (r=0.31) and diastolic blood pressure (r=0.37), and waist circumferences (r=0.36). Substantial weight loss in 21 children led to a significant decrease of fetuin-A and the prevalence of NAFLD in contrast to the 15 children without substantial weight loss. CONCLUSIONS Fetuin-A levels were higher in children with NAFLD, and were related to insulin resistance and to features of the MetS in both cross-sectional and longitudinal analyses. Therefore, fetuin-A might be a new promising link between obesity and its comorbidities.

Genetic variation at chromosome 1p13.3 affects sortilin mRNA expression, cellular LDL-uptake and serum LDL levels which translates to the risk of coronary artery disease

BACKGROUND A single nucleotide polymorphism (SNP) rs599839 located at chromosome 1p13.3 has previously been associated with risk of coronary artery disease (CAD) and with serum levels of low-density lipoprotein cholesterol (LDL-C). A functional link explaining the association of SNP rs599839 with LDL-C levels and CAD risk has not yet been elucidated. METHODS We analyzed the association of rs599839 with LDL-C in 6605 individuals across a wide age spectrum and with CAD in four case-control studies comprising 4287 cases and 7572 controls. Genome-wide expression array data was used to assess the association of SNP rs599839 with gene expression at chromosome 1p13. Finally, we overexpressed sortilin in transfected cells to study LDL-uptake in vitro. RESULTS Each copy of the G-allele of rs599839 associated with a decrease of serum LDL-C by 0.14 mmol/L (90% confidence interval (CI) 0.09-0.17 mmol/L, p=2.6 x 10(-11)). Moreover, each copy of the G-allele associated with a 9% decrease of CAD risk (90% CI 4-14%) in the presently studied four case-control samples and with a 13% decrease (90% CI 10-17%, p=2.18 x 10(-9)) in a pooled meta-analysis including recent genome-wide association studies on CAD. The same allele was associated with higher mRNA-expression levels of the multiligand receptor sortilin (log transformed mRNA AA vs. GG=8.31 vs. 8.55; p=0.01). Overexpression of SORT1 cDNA resulted in a significant increase in LDL-particle uptake (+23%, p=0.01). CONCLUSIONS Rs599839 associates with decreased LDL-C and a lower risk of CAD. Effects appear to be mediated by increased sortilin expression and subsequently enhanced LDL-uptake into cells.

Recessive mutations in a distal PTF1A enhancer cause isolated pancreatic agenesis

The contribution of cis-regulatory mutations to human disease remains poorly understood. Whole-genome sequencing can identify all noncoding variants, yet the discrimination of causal regulatory mutations represents a formidable challenge. We used epigenomic annotation in human embryonic stem cell (hESC)-derived pancreatic progenitor cells to guide the interpretation of whole-genome sequences from individuals with isolated pancreatic agenesis. This analysis uncovered six different recessive mutations in a previously uncharacterized ∼400-bp sequence located 25 kb downstream of PTF1A (encoding pancreas-specific transcription factor 1a) in ten families with pancreatic agenesis. We show that this region acts as a developmental enhancer of PTF1A and that the mutations abolish enhancer activity. These mutations are the most common cause of isolated pancreatic agenesis. Integrating genome sequencing and epigenomic annotation in a disease-relevant cell type can thus uncover new noncoding elements underlying human development and disease.

Lifelong reduction of LDL-cholesterol related to a common variant in the LDL-receptor gene decreases the risk of coronary artery disease--a Mendelian Randomisation study.

Background Rare mutations of the low-density lipoprotein receptor gene (LDLR) cause familial hypercholesterolemia, which increases the risk for coronary artery disease (CAD). Less is known about the implications of common genetic variation in the LDLR gene regarding the variability of cholesterol levels and risk of CAD. Methods Imputed genotype data at the LDLR locus on 1 644 individuals of a population-based sample were explored for association with LDL-C level. Replication of association with LDL-C level was sought for the most significant single nucleotide polymorphism (SNP) within the LDLR gene in three European samples comprising 6 642 adults and 533 children. Association of this SNP with CAD was examined in six case-control studies involving more than 15 000 individuals. Findings Each copy of the minor T allele of SNP rs2228671 within LDLR (frequency 11%) was related to a decrease of LDL-C levels by 0.19 mmol/L (95% confidence interval (CI) [0.13–0.24] mmol/L, p = 1.5×10−10). This association with LDL-C was uniformly found in children, men, and women of all samples studied. In parallel, the T allele of rs2228671 was associated with a significantly lower risk of CAD (Odds Ratio per copy of the T allele: 0.82, 95% CI [0.76–0.89], p = 2.1×10−7). Adjustment for LDL-C levels by logistic regression or Mendelian Randomisation models abolished the significant association between rs2228671 with CAD completely, indicating a functional link between the genetic variant at the LDLR gene locus, change in LDL-C and risk of CAD. Conclusion A common variant at the LDLR gene locus affects LDL-C levels and, thereby, the risk for CAD.

A new link between skeleton, obesity and insulin resistance: relationships between osteocalcin, leptin and insulin resistance in obese children before and after weight loss.

Background:The skeleton is regarded recently as an endocrine organ that affects energy metabolism. However, there are very limited data available concerning the relationships between the osteoblast-derived hormone osteocalcin, weight status, adiponectin and leptin in obese humans, especially in children.Methods:We analyzed osteocalcin, adiponectin, leptin and insulin resistance (IR) index homeostasis model assessment (HOMA) in 60 obese and 19 age- and gender-matched normal weight children. Furthermore, these parameters were determined in 60 obese children after participating in an outpatient 1-year lifestyle intervention based on exercise, behavior and nutrition therapy.Results:Sixty obese children had significantly lower osteocalcin levels (26.8±0.8 ng ml−1) than 19 normal weight controls (32.2±2.3 ng ml−1). Boys (29.9±1.1 ng ml−1) showed significantly (P=0.046) higher osteocalcin levels compared with girls (26.4±1.2 ng ml−1). In stepwise multiple linear regression analysis adjusted for age, gender and pubertal stage, osteocalcin was significantly negatively related to leptin and HOMA, but not to adiponectin. Changes of osteocalcin in the course of 1 year correlated significantly negatively with changes of IR index HOMA (r=−0.25), standard deviation score–body mass index (SDS–BMI) (r=−0.33) and leptin (r=−0.50). Substantial weight loss in 29 obese children led to a significant increase in osteocalcin and a significant decrease in leptin and HOMA. In 31 obese children without substantial weight loss, osteocalcin levels did not change significantly in the course of 1 year.Conclusion:Osteocalcin levels were lower in obese children and were related to IR and leptin both in cross-sectional and longitudinal analyses. Therefore, osteocalcin might be a new promising link between obesity and IR.

Changes in adipose-derived inflammatory cytokines and chemokines after successful lifestyle intervention in obese children

Obesity has been associated with low-grade chronic systemic inflammation, potentially leading to insulin resistance. This study was designed to examine relationships between cardiovascular risk factors, insulin resistance, and simultaneously measured inflammatory parameters in obese children. We examined serum inflammatory parameters in 115 obese children and 30 normal-weight controls; 62 obese children were followed longitudinally in a 1-year obesity intervention study. Serum concentrations of adipose tissue hormones adiponectin and resistin as well as adipocytokines were assessed. Cross-sectional analysis showed significant correlations between standard deviation score body mass index and resistin (P = .0004) as well as monocyte chemoattractant protein-1 (MCP-1, P = .04). Increased homeostasis model assessment of insulin resistance index greater than 95th percentile was present in 32% of obese patients, correlating with adiponectin (r = -0.40, P = .0007). Significant correlations were found between adiponectin and several mediators of inflammation (interleukins [ILs] IL-1β, IL-6, and IL-8 and tumor necrosis factor-α). In longitudinal analysis, substantial weight loss (change standard deviation score body mass index >0.5) observed after intervention in 29 children was associated with a significant decrease in blood pressure, homeostasis model assessment of insulin resistance index, and serum concentrations of insulin and IL-1β, IL-8, and MCP-1, but increase of adiponectin (all Ps < .05). In 33 children without substantial weight loss, resistin and MCP-1 levels increased after 1 year. Changes in IL-1β correlated positively with changes of weight status, interferon-γ, IL-6, IL-8, and tumor necrosis factor-α (all Ps < .01). Our study demonstrates significant correlations between different metabolic risk factors at baseline and after changes of weight status and that weight loss in obese children reduces low-grade inflammation, insulin resistance, and blood pressure.

Fibroblast Growth Factor 21 (FGF-21) and Its Relation to Obesity, Metabolic Syndrome, and Nonalcoholic Fatty Liver in Children: A Longitudinal Analysis

CONTEXT Fibroblast growth factor 21 (FGF-21), a potent activator of glucose uptake, has been proposed to be related to insulin resistance, metabolic syndrome (MetS), nonalcoholic fatty liver disease (NAFLD), and weight status. OBJECTIVE Our objective was to study the relationships between FGF-21, parameters of MetS, and NAFLD before and after weight loss in obese children. DESIGN AND SETTING This was a cross-sectional comparison between obese and normal-weight children and longitudinal 1-yr follow-up study in obese children participating in a lifestyle intervention in a primary care setting. PATIENTS Patients included 60 obese and 40 lean children of same age, gender, and pubertal stage. INTERVENTION The outpatient 1-yr intervention program was based on exercise, behavior, and nutrition therapy. MAIN OUTCOMES MEASURES We evaluated fasting serum FGF-21, weight status [body mass index (BMI) expressed as sd score (SDS)], body fat, insulin resistance index (homeostasis model assessment), leptin, transaminases, free fatty acids (FFA), waist circumference, blood pressure, and lipids. RESULTS Compared with the normal-weight children, obese children demonstrated significantly (P < 0.001) increased FGF-21, leptin, and homeostasis model assessment levels. FGF-21 was significantly (P < 0.05) correlated to BMI, SDS-BMI, FFA, and leptin both in cross-sectional and longitudinal analyses but not to any additional analyzed parameter. Children with and without MetS or NAFLD did not differ significantly with respect to their FGF-21 concentrations. A decrease of SDS-BMI was associated with a significant (P = 0.038) decrease of FGF-21 levels (mean -34%). CONCLUSIONS FGF-21 concentrations are reversibly increased in obese children and are related to leptin and FFA. However, our data do not support a significant relationship between FGF-21, insulin resistance, and features of MetS or NAFLD in children.

Ghrelin levels before and after reduction of overweight due to a low-fat high-carbohydrate diet in obese children and adolescents

BACKGROUND:There are conflicting results for ghrelin changes in reduction of overweight. Increasing ghrelin levels in weight reduction are considered to be responsible for compensatory mechanisms that make the reduction of overweight unlikely to be sustained.METHODS:We have analyzed fasting serum ghrelin levels, weighed dietary record and, as biochemical markers of clinically relevant reduction of overweight, leptin, adiponectin and insulin levels and insulin resistance measured by homeostasis model assessment (HOMA) at baseline and after a 1-y outpatient weight reduction program based on a high-carbohydrate and low-fat diet in 37 obese children (median age 10 y). We divided these children into two subgroups according to their degree of weight loss (substantial reduction of overweight: decrease in SDS-BMI≥0.5). Furthermore, we analyzed ghrelin levels in 16 normal-weight children.RESULTS:Obese children demonstrated significant (P<0.001) lower ghrelin levels compared to normal-weight children. Daily caloric intake (P=0.004) and percentage fat content decreased significantly (P<0.001), while percentage carbohydrate content increased significantly (P=0.003) between baseline and 1-y follow-up in the obese children. The substantial reduction of overweight in 16 children (median SDS-BMI=−0.7) was associated with significant changes in insulin resistance (median decrease of HOMA 27%; P=0.013), insulin (median decrease 25%, P=0.036), adiponectin (median increase 15%; P=0.003), and leptin levels (median decrease 19%; P=0.023), while there were no significant changes in ghrelin levels (median increase 4%; P=0.326). In the 21 children without substantial reduction of overweight (median SDS-BMI=−0.3), there were no significant changes in insulin resistance and in insulin, adiponectin, leptin and ghrelin levels.CONCLUSIONS:We conclude that in obese children, low-fat high-carbohydrate diet-induced weight loss does not change ghrelin secretion, but significantly decreases leptin levels, increases adiponectin levels and improves insulin resistance determined by significantly decreased insulin resistance indices as well as lowered serum insulin levels.