ABSTRACT
Rapid eye movement (REM) sleep behavior disorder (RBD) is defined as a parasomnia characterized by loss of REM sleep-associated atonia and the presence of motor activity during dreaming typically presenting with an aggressive dream content. Epidemiological data on the prevalence of RBD are insufficient but it can be idiopathic or symptomatic. A video-audio polysomnography is essential for diagnosis. Clonazepam and melatonin are available as pharmaceutical treatment. Recent studies demonstrated that individuals suffering from idiopathic RBD carry a high specific risk (up to 80 %) for developing a neurodegenerative disorder of the α-synucleinopathy type (e.g. Parkinson's disease, dementia with Lewy bodies and multiple system atrophy) within 10-20 years. The current article provides a short overview of symptoms, epidemiology, pathophysiology, diagnosis and therapy of RBD.
Subject(s)
Anticonvulsants/therapeutic use , Neurodegenerative Diseases/diagnosis , Neurodegenerative Diseases/therapy , Polysomnography , REM Sleep Behavior Disorder/diagnosis , REM Sleep Behavior Disorder/therapy , Humans , Neurodegenerative Diseases/complications , Neurodegenerative Diseases/metabolism , Prodromal Symptoms , REM Sleep Behavior Disorder/complications , REM Sleep Behavior Disorder/metabolism , alpha-Synuclein/metabolismABSTRACT
Compound optics such as lens systems can overcome the limitations concerning resolution, efficiency, or aberrations which fabrication constraints would impose on any single optical element. In this work we demonstrate unprecedented sub-5 nm point focusing of hard x-rays, based on the combination of a high gain Kirkpatrick-Baez (KB) mirror system and a high resolution W/Si multilayer zone plate (MZP) for ultra-short focal length f. The pre-focusing allows limiting the MZP radius to below 2 µm, compatible with the required 5 nm structure width and essentially unlimited aspect ratios, provided by enabling fabrication technology based on pulsed laser deposition (PLD) and focused ion beam (FIB).
ABSTRACT
OBJECTIVES: We aimed to provide a consensus statement by the International Rapid Eye Movement Sleep Behavior Disorder Study Group (IRBD-SG) on devising controlled active treatment studies in rapid eye movement sleep behavior disorder (RBD) and devising studies of neuroprotection against Parkinson disease (PD) and related neurodegeneration in RBD. METHODS: The consensus statement was generated during the fourth IRBD-SG symposium in Marburg, Germany in 2011. The IRBD-SG identified essential methodologic components for a randomized trial in RBD, including potential screening and diagnostic criteria, inclusion and exclusion criteria, primary and secondary outcomes for symptomatic therapy trials (particularly for melatonin and clonazepam), and potential primary and secondary outcomes for eventual trials with disease-modifying and neuroprotective agents. The latter trials are considered urgent, given the high conversion rate from idiopathic RBD (iRBD) to Parkinsonian disorders (i.e., PD, dementia with Lewy bodies [DLB], multiple system atrophy [MSA]). RESULTS: Six inclusion criteria were identified for symptomatic therapy and neuroprotective trials: (1) diagnosis of RBD needs to satisfy the International Classification of Sleep Disorders, second edition, (ICSD-2) criteria; (2) minimum frequency of RBD episodes should preferably be ⩾2 times weekly to allow for assessment of change; (3) if the PD-RBD target population is included, it should be in the early stages of PD defined as Hoehn and Yahr stages 1-3 in Off (untreated); (4) iRBD patients with soft neurologic dysfunction and with operational criteria established by the consensus of study investigators; (5) patients with mild cognitive impairment (MCI); and (6) optimally treated comorbid OSA. Twenty-four exclusion criteria were identified. The primary outcome measure for RBD treatment trials was determined to be the Clinical Global Impression (CGI) efficacy index, consisting of a four-point scale with a four-point side-effect scale. Assessment of video-polysomnographic (vPSG) changes holds promise but is costly and needs further elaboration. Secondary outcome measures include sleep diaries; sleepiness scales; PD sleep scale 2 (PDSS-2); serial motor examinations; cognitive indices; mood and anxiety indices; assessment of frequency of falls, gait impairment, and apathy; fatigue severity scale; and actigraphy and customized bed alarm systems. Consensus also was established for evaluating the clinical and vPSG aspects of RBD. End points for neuroprotective trials in RBD, taking lessons from research in PD, should be focused on the ultimate goal of determining the performance of disease-modifying agents. To date no compound with convincing evidence of disease-modifying or neuroprotective efficacy has been identified in PD. Nevertheless, iRBD patients are considered ideal candidates for neuroprotective studies. CONCLUSIONS: The IRBD-SG provides an important platform for developing multinational collaborative studies on RBD such as on environmental risk factors for iRBD, as recently reported in a peer-reviewed journal article, and on controlled active treatment studies for symptomatic and neuroprotective therapy that emerged during the 2011 consensus conference in Marburg, Germany, as described in our report.
Subject(s)
Neuroprotective Agents/therapeutic use , Parkinson Disease/prevention & control , REM Sleep Behavior Disorder/diagnosis , REM Sleep Behavior Disorder/drug therapy , Clinical Trials as Topic/methods , Clinical Trials as Topic/standards , Clonazepam/therapeutic use , Consensus , GABA Modulators/therapeutic use , Humans , Melatonin/therapeutic use , Parkinson Disease/epidemiology , REM Sleep Behavior Disorder/epidemiology , Risk FactorsABSTRACT
The clinical diagnosis of Parkinson's disease (PD) according to the UK Brain Bank criteria is based on the presence of motor symptoms and the response to dopaminergic medication. According to these criteria the clinical diagnosis is delineated too late when more than 50 % of the dopaminergic neurons are already degenerated. In recent years interest has shifted increasingly more towards non-motor symptoms (NMS), such as rapid eye movement (REM) sleep behavior disorder (RBD), constipation, hyposmia and neuropsychiatric as well as cognitive symptoms. It was shown that NMS can precede the motor symptoms by some years and may thus possibly enable support of an earlier clinical diagnosis. Furthermore, cerebrospinal fluid or blood biomarkers as well as brain imaging techniques can objectively support an earlier diagnosis of PD. This article reviews important NMSs (e.g. RBD, hyposmia and neuropsychiatric/cognitive symptoms) as well as the current status on biomarkers and brain imaging in early (premotor) phases of PD and their relevance for the early diagnosis.
Subject(s)
Cognition Disorders/diagnosis , Dementia/diagnosis , Early Diagnosis , Oculomotor Nerve Diseases/diagnosis , Olfaction Disorders/diagnosis , Parkinson Disease/diagnosis , Sleep Wake Disorders/diagnosis , Biomarkers/metabolism , Cognition Disorders/etiology , Cognition Disorders/metabolism , Dementia/etiology , Dementia/metabolism , Diagnosis, Differential , Humans , Oculomotor Nerve Diseases/etiology , Oculomotor Nerve Diseases/metabolism , Olfaction Disorders/etiology , Olfaction Disorders/metabolism , Parkinson Disease/complications , Parkinson Disease/metabolism , Sleep Wake Disorders/etiology , Sleep Wake Disorders/metabolismABSTRACT
The carnitine palmitoyltransferase (CPT) enzyme system facilitates the transport of long-chain fatty acids into mitochondria to provide substrates for ß-oxidation. We performed an analysis including three coding SNP in the muscle isoform of the CPT1b gene (rs3213445, rs2269383 and rs470117) and one coding SNP in the CPT2 gene (rs1799821) to find associations with traits of the metabolic syndrome (MetS). Male participants (n 755) from the Metabolic Intervention Cohort Kiel were genotyped and phenotyped for features of the MetS. Participants underwent a glucose tolerance test and a postprandial assessment of metabolic variables after a standardised mixed meal. Carriers of the rare CPT1b 66V (rs3213445) allele had significantly higher γ-glutamyl transpeptidase (GGT), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) activities (P< 0·0001, P= 0·03 and P= 0·048, respectively) and a higher fatty liver index (FLI, P= 0·026). Fasting and postprandial TAG (P= 0·007 and P= 0·009, respectively) and fasting glucose (P= 0·012) were significantly higher in 66V-allele carriers. The insulin sensitivity index determined after a glucose load was lower in those subjects (P= 0·005). Total cholesterol (P= 0·051) and LDL-cholesterol (P= 0·062) tended to be higher in 66V-allele carriers when compared with I66I homozygotes. Homozygosity of the rare K531E allele presented with lower GGT and GOT activities (P= 0·011 and P= 0·027, respectively). E531E homozygotes tended to have lower GPT and FLI (P= 0·078 and P= 0·052, respectively). CPT2 V368I (rs1799821) genotypic groups did not differ in the investigated anthropometric and metabolic parameters. The present results confirm the association of CPT1b coding polymorphisms with the MetS, with a deleterious effect of the CPT1b I66V and a protective impact of the CPT1b K531E SNP, whereas haplotype analysis indicates a relevance of the E531K polymorphism only.
Subject(s)
Carnitine O-Palmitoyltransferase/genetics , Haplotypes , Metabolic Syndrome/genetics , Polymorphism, Single Nucleotide/genetics , Aged , Aspartate Aminotransferases/blood , Fasting , Fatty Liver/genetics , Genotype , Glucose Tolerance Test , Humans , Insulin Resistance/genetics , Male , Middle Aged , Postprandial Period , Triglycerides/blood , gamma-Glutamyltransferase/bloodABSTRACT
Understanding the function of fat metabolism during differentiation of human preadipocytes to fully developed fat tissue has been the aim of various studies in the past decades. Due to the lack of suitable human cell culture lines, experimental research predominantly focused on rodent models and nonhuman cell culture systems. Here, we demonstrate that a human preadipocyte cell line SGBS is well suited to examine differential expression of the Acyl-CoA binding protein (ACBP) during adipogenesis. The Acbp gene expresses various alternative high- and low-abundant transcript variants encoding ACBP protein isoforms, which play a central role in fat metabolism. Whereas the low-abundant transcript Acbp-1G is downregulated during SGBS adipogenesis, the high-abundant and well established transcripts Acbp-1A (1) and -1B are moderately (2-4-fold) upregulated. In contrast, the alternative high-abundant transcript Acbp-1C is strongly (29-fold) upregulated at mRNA and protein level indicating that particularly ACBP-1C functions in lipogenic processes during fat cell differentiation in humans.
Subject(s)
Adipocytes/metabolism , Alternative Splicing/genetics , Diazepam Binding Inhibitor/metabolism , Cell Differentiation/genetics , Cell Line , Humans , Leptin/genetics , Leptin/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolismABSTRACT
Maximal oxygen uptake (VO2max) is one of the most important determinants of elite endurance performance. VO2max is determined by a whole range of genetic and environmental factors. Single nucleotide polymorphisms (SNPs) in muscle myostatin (MSTN) and creatine kinase (CKM) genes are candidates for VO2max and skeletal muscle performance phenotypes. Common MSTN (rs3791783, rs11681628 and rs7570532) and CKM (rs344816, rs10410448, rs432979, rs1133190, rs7260359, rs7260463 and rs4884) SNPs, selected from HapMap CEU data in order to tag the genetic variability of the proteins, were genotyped in 316 male Caucasian elite endurance athletes and 304 sedentary controls from the Genathlete study. Association with elite endurance performance was determined by logistic regression analysis. The P-value for statistical significance was set at <0.01. None of the SNPs or haplotypes showed a significant association with elite endurance status. We conclude that common variants of MSTN and CKM genes do not play a role in attaining high-level endurance performance in Caucasian populations.
Subject(s)
Athletic Performance/physiology , Creatine Kinase, MM Form/genetics , Myostatin/genetics , Physical Endurance/genetics , Polymorphism, Single Nucleotide/genetics , Creatine Kinase, MM Form/metabolism , Genotype , Humans , Male , Myostatin/metabolism , Oxygen Consumption/genetics , Oxygen Consumption/physiologyABSTRACT
Long-term care after deep brain stimulation for Parkinson's disease requires regular technical check-ups as well as clinical follow-up. Residual or emerging difficulties with gait, balance or speech should be addressed by specific rehabilitation programs. In cases of psychosocial maladjustment, psychotherapy or family counseling may prove helpful. After consolidation of stimulation parameters, pharmacotherapy can be tailored according to the individual needs, following the same guidelines as for Parkinson's disease patients without deep brain stimulation. In cases of clinical deterioration, malfunctioning of the stimulation system, comorbidity or disease progression has to be considered and treated accordingly. Structured long-term care programs may contribute to patient satisfaction and ensure quality of life.
Subject(s)
Aftercare/methods , Deep Brain Stimulation/methods , Parkinson Disease/therapy , Aftercare/psychology , Antiparkinson Agents/therapeutic use , Combined Modality Therapy , Deep Brain Stimulation/adverse effects , Disease Progression , Family Therapy , Globus Pallidus/physiopathology , Humans , Long-Term Care/methods , Long-Term Care/psychology , Parkinson Disease/physiopathology , Parkinson Disease/psychology , Patient Education as Topic , Patient Satisfaction , Physical Therapy Modalities , Psychotherapy , Quality of Life/psychology , Social Adjustment , Subthalamic Nucleus/physiopathologyABSTRACT
In the present study we performed a transcriptom-based analysis of human Acyl-CoA-Binding-Protein (ACBP) target genes. By applying Genomatix BiblioSphere expert level based co-citation filter 4 (GFG level 4) ras homolog gene family member B (RhoB) and its interacting rhophilin-2 (Rhpn2) were refined from 64 ACBP sensitive genes. TaqMan-based qRT-PCR confirmed the accuracy of the array-derived expression data. Based on Gene Ontology (GO) classification RhoB and Rhnp2 were allocated to endosomal transport and signaling processes. Thus, we suggest RhoB and Rhnp2 as ACBP target genes contributing to the proposed and evolutionary conserved function of ACBP in vesicular transport processes.
Subject(s)
Diazepam Binding Inhibitor/metabolism , Gene Expression Profiling , Adaptor Proteins, Signal Transducing/metabolism , Biological Transport , Endosomes/metabolism , Hep G2 Cells , Humans , RNA Interference , RNA, Small Interfering , Signal Transduction , rhoB GTP-Binding Protein/metabolismABSTRACT
Deep brain stimulation (DBS) in the nucleus ventralis intermedius thalami (VIM) is a common procedure to treat disabling tremor in multiple sclerosis which is refractory to pharmacological treatment. The sparse studies on DBS in multiple sclerosis tremor remain controversial regarding the clinical effect on postural and action tremor of hands, trunk and head. Furthermore, it remains unclear whether DBS in multiple sclerosis tremor is superior to thalamotomy and whether patients show an overall improvement in quality of life and activities of daily living. Therefore, the consensus recommendations of the German Deep Brain Stimulation Study Group rely primarily on expert opinion and include (1) extensive preoperative characterisation of tremor, ataxia with accompanying disabilities, status of the multiple sclerosis, co-morbidities and burden of disease, (2) careful intraoperative testing of effects and side effects and (3) intensive postoperative testing and programming as well as regular re-evaluation of the therapeutic effect.
Subject(s)
Deep Brain Stimulation/standards , Multiple Sclerosis/complications , Multiple Sclerosis/therapy , Practice Guidelines as Topic , Tremor/complications , Tremor/therapy , Germany , HumansABSTRACT
In Germany, deep brain stimulation (DBS) of the thalamic ventralis intermedius nucleus (VIM) is licensed for treatment of essential tremor in cases unresponsive to pharmacotherapy. Especially a bothersome hand tremor interfering with activities of daily living will improve, whereas head, tongue or vocal tremor shows less response. DBS was proven to be superior to lesional thalamotomy with better functional outcome and less adverse effects. The consensus statement presented here reflects the current recommendations of the German Deep Brain Stimulation Study Group for inclusion and exclusion criteria as well as for peri-, intra- and postoperative neurological management.
Subject(s)
Deep Brain Stimulation/standards , Dystonia/therapy , Essential Tremor/therapy , Neurology/standards , Practice Guidelines as Topic , Germany , HumansABSTRACT
Medical treatment of dystonia, particularly generalised forms of the disorder, is often not satisfactory or causes intolerable side effects. In focal dystonia, a reasonable treatment option with botulinum toxin exists but some patients either do not respond well or develop neutralising antibodies with secondary therapy failure. Deep brain stimulation (DBS) of the globus pallidus internus has been shown to be effective in both generalised and focal dystonia. This paper gives recommendations regarding the use of DBS in different forms of dystonia based on the currently available scientific data as well as the longstanding personal experience of the authors. The inclusion criteria for DBS candidates as well as the peri- and postoperative patient management are addressed. These recommendations were developed in a consensus procedure in the German Deep Brain Stimulation Association.
Subject(s)
Deep Brain Stimulation/standards , Dystonia/therapy , Neurology/standards , Practice Guidelines as Topic , Germany , HumansABSTRACT
Deep brain stimulation (DBS) has been shown to be effective for levodopa-responsive symptoms and tremor in Parkinson's disease (PD). The subthalamic nucleus (STN) is the preferred target for most patients suffering from late stage motor complications of the disorder. STN DBS is superior to best medical treatment concerning the control of motor fluctuations and the increase of on-time without dyskinesias. In contrast to DBS of the internal pallidum (GPi), STN stimulation also permits a reduction of the dopaminergic medication. Long-term data demonstrated sustained effectiveness of STN DBS despite progressive disease. DBS of the thalamic ventral intermediate nucleus (VIM) is an alternative target in older PD patients with severe PD tremor refractory to medication. In order to minimize potential risks and side effects, the use of DBS needs careful adherence to inclusion and exclusion criteria for eligible PD patients. This paper summarizes the current consensus recommendations of the German Deep Brain Stimulation Association for DBS in PD.
Subject(s)
Deep Brain Stimulation/standards , Neurology/standards , Parkinson Disease/therapy , Practice Guidelines as Topic , Germany , HumansABSTRACT
In this study we tested whether the type 2 diabetes mellitus associated prostaglandin E synthase 2 arginine to histidine polymorphism at position 298 (R298H) influences prostaglandin E2 levels in humans. Fasting prostaglandin E2 was determined in the blood of subjects carrying different genotypes of the R298H polymorphism. Subjects were matched by sex, age, and body mass index. No differences in prostaglandin E2 levels were found with respect to genotypes when considering the whole group. Male homozygous histidine carriers showed elevated prostaglandin E2 levels compared to heterozygous carriers and homozygous arginine carriers (188.2+/-42.4 vs. 80.4+/-26.5pg/ml, p=0.021; and vs. 92.9+/-15.3pg/ml, p=0.11). These differences were not evident in female subjects. In contrast, 6-keto-prostaglandin F1alpha levels as independent marker of arachidonic acid metabolism showed ambiguous results. Nevertheless, preliminary evidence of the prostaglandin E synthase 2 R298H polymorphism possibly influencing prostaglandin E2 blood levels in a gender-specific manner was obtained.
Subject(s)
Diabetes Mellitus, Type 2/blood , Dinoprostone/blood , Intramolecular Oxidoreductases/genetics , Adult , Aged , Dinoprostone/genetics , Fasting/blood , Female , Humans , Male , Middle Aged , Polymorphism, Genetic , Prostaglandin-E Synthases , Sex FactorsSubject(s)
Diabetes Mellitus, Type 2/genetics , Genetic Variation , Homeodomain Proteins/genetics , Transcription Factors/genetics , Adult , Aged , Genes, Dominant , Genetic Predisposition to Disease , Genotype , Germany , Humans , Middle Aged , Models, Genetic , Polymorphism, Genetic , Prospective Studies , Risk FactorsABSTRACT
The fatty acid binding protein 2 (FABP2) mediates the intestinal uptake of fatty acids. We and others have identified six FABP2 promoter polymorphisms which result in two haplotypes, A and B. Reporter-gene assays indicated different activity in FABP2 promoter alleles A and B and different responsiveness to PPAR ligands. IN SILICO analysis revealed different putative binding sites in FABP2 haplotypes for retinoid-dependent transcription factors. Therefore, we assumed that retinol supplementation may effect postprandial fat uptake differently in men with FABP2 promoter haplotype A and B. To test this hypothesis, we administered 5000 I.U. retinol/day for 8 weeks to 19 homozygotes for AA and 21 homozygotes for BB and assessed the alteration of postprandial triglycerides during this intervention. FABP2 genotype groups did not significantly differ in anthropometric and laboratory parameters. The alteration of postprandial triglycerides did not differ significantly between genotypes during intervention. This also held true after adjustment for BMI. Furthermore, in a subgroup which had a combination of promoter and common exon polymorphism, the alteration of the postprandial triglycerides did not differ between genotypes. In conclusion, the postprandial triglyceride metabolism of FABP2 promoter AA and BB did not respond differently to retinol administration even though IN SILICO analysis suggested this.
Subject(s)
Fatty Acid-Binding Proteins/genetics , Postprandial Period/drug effects , Vitamin A/pharmacology , Blood Glucose/metabolism , Computational Biology , DNA/genetics , Data Interpretation, Statistical , Exons/genetics , Fatty Acid-Binding Proteins/metabolism , Fatty Acids, Nonesterified/blood , Female , Haplotypes , Homeostasis/drug effects , Humans , Insulin/blood , Male , Middle Aged , Promoter Regions, Genetic/genetics , Reverse Transcriptase Polymerase Chain Reaction , Triglycerides/blood , Vitamin A/bloodABSTRACT
Deep brain stimulation of the subthalamic nucleus is an important treatment option for advanced stages of idiopathic Parkinson's disease, leading to significant improvement of motor symptoms in suited patients. Hardware-related complications such as technical malfunction, skin erosion, and infections however cause patient discomfort and additional expense. The patient presented here suffered a putrid infection of the impulse generator site following only local dental treatment of apical parodontitis. Therefore, prophylactic systemic antibiotic treatment is recommended for patients with implanted deep brain stimulation devices in case of operations, dental procedures, or infectious disease.
Subject(s)
Deep Brain Stimulation/adverse effects , Deep Brain Stimulation/instrumentation , Electrodes, Implanted/adverse effects , Periodontal Abscess/etiology , Periodontitis/etiology , Prosthesis-Related Infections/etiology , Aged , Humans , Male , Periodontal Abscess/prevention & control , Periodontitis/prevention & control , Prosthesis-Related Infections/prevention & controlABSTRACT
Fatty acid-binding protein 2 (FABP2) is a cytosolic protein expressed exclusively in epithelial cells of the small intestine. Some, albeit not conclusive, evidence indicates that the Thr-allele of FABP2 Ala54Thr polymorphism is associated with type 2 diabetes. More recently, common FABP2 promoter polymorphisms have shown association with postprandial increase of triglycerides, body composition and plasma lipid levels. Therefore, we reasoned that variants in the FABP2 promoter may also predispose to type 2 diabetes mellitus. In our Caucasian study population, we found three SNPs and three insertion-deletion polymorphisms that are in complete linkage disequilibrium defining promoter haplotype A and B within 1kb 5' of the FABP2 initiation codon. Haplotype calculations indicated that the FABP2 promoter and Ala54Thr variants were strongly linked. Functional analysis of promoter fragments demonstrated that haplotype difference is caused by polymorphisms within 260 bp downstream of the FABP2 initiation codon. Using a prospective case-control study nested within the EPIC-Potsdam cohort of 192 incident type 2 diabetes cases and 384 sex-/age-matched controls, male subjects carrying the FABP2 haplotype B allele showed significantly decreased risk of type 2 diabetes when adjusted for BMI (OR = 0.50, 95 % CI = 0.28 - 0.87, p < 0.05) and additional covariates (OR = 0.42, 95 % CI 0.22 - 0.81, p < 0.01). Further adjustment for the Ala54Thr polymorphism revealed an OR of 0.18 (95 % CI 0.06 - 0.49, p < 0.001). Similarly, Ala/Ala homozygote males carrying the promoter haplotype B had decreased risk (0.33, 0.11 - 0.94, p < 0.05) of type 2 diabetes after stratification for the Ala54Thr polymorphism. FABP2 promoter haplotypes or genotype combinations defined by the promoter and Ala54Thr polymorphism were not associated with BMI, body fat, leptin, HbA (1c), total cholesterol or HDL. In conclusion, our findings suggest that the functional FABP2 promoter haplotype may contribute to type 2 diabetes in a sex-specific manner.
Subject(s)
Diabetes Mellitus, Type 2/genetics , Fatty Acid-Binding Proteins/genetics , Haplotypes/genetics , Promoter Regions, Genetic/genetics , Adult , Aged , Body Mass Index , Caco-2 Cells , Case-Control Studies , Female , Genetic Linkage , Genetic Predisposition to Disease , HeLa Cells , Humans , Male , Middle Aged , Polymorphism, Genetic , Prospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Sex Characteristics , TransfectionABSTRACT
The T54 variant of the FABP2 gene has shown an association with the insulin resistance syndrome in some, but not all, studies. Here, we tested the hypothesis that the association between FABP2 A54T genotype and type 2 diabetes (T2DM) is confounded by body mass index (BMI) and is different between the two genders. 192 incident cases of T2DM and 384 sex- and age-matched controls were taken from the EPIC-Potsdam study cohort. Logistic regression analyses revealed that BMI was a strong confounder for diabetes risk association among women. When adjusted for BMI, the homozygous T54 variant was significantly associated with reduced risk of T2DM in women (OR = 0.24, 95 %CI: 0.07 - 0.82), but not in men in the co-dominant inheritance model. Accordingly, HbA (1c) values were significantly lower in women carrying two T54 alleles with BMI regarded as covariate. While accounting for potentially confounding effects, linear trends of increased BMI and leptin values were observed in women according to the presence of T54 alleles. The interaction term (p = 0.04) of continuous BMI and T54-coding genotypes suggested that the T54 variant is an effect-modifier for BMI in females. We conclude that the T54 allele of FABP2 A54T is associated both with higher BMI and reduced risk of T2DM in women from the German EPIC-Potsdam study.
Subject(s)
Diabetes Mellitus, Type 2/genetics , Fatty Acid-Binding Proteins/genetics , Obesity/genetics , Polymorphism, Genetic , Adult , Aged , Alleles , Body Mass Index , Cohort Studies , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Germany , Humans , Logistic Models , Male , Middle Aged , Risk Factors , Sex CharacteristicsABSTRACT
H(+)/peptide cotransport was studied in brush-border membrane vesicles (BBMV) from the intestine of the haemoglobinless Antarctic teleost Chionodraco hamatus by monitoring peptide-dependent intravesicular acidification with the pH-sensitive dye Acridine Orange. Diethylpyrocarbonate-inhibited intravesicular acidification was specifically achieved in the presence of extravesicular glycyl-L-proline (Gly-L-Pro) as well as of glycyl-L-alanine (Gly-L-Ala) and D-phenylalanyl-L-alanine (D-Phe-L-Ala). H(+)/Gly-L-Pro cotransport displayed saturable kinetics, involving a single carrier system with an apparent substrate affinity (K(m,app)) of 0.806+/-0.161 mmol l(-1). Using degenerated primers from eel and human (PepT1) transporter sequence, a reverse transcription-polymerase chain reaction (RT-PCR) signal was detected in C. hamatus intestine. RT-PCR paralleled kinetic analysis, confirming the hypothesis of the existence of a PepT1-type transport system in the brush-border membranes of icefish intestine. Functional expression of H(+)/peptide cotransport was successfully performed in Xenopus laevis oocytes after injection of poly(A)(+) RNA (mRNA) isolated from icefish intestinal mucosa. Injection of mRNA stimulated D-Phe-L-Ala uptake in a dose-dependent manner and an excess of glycyl-L-glutamine inhibited this transport. H(+)/peptide cotransport in the Antarctic teleost BBMV exhibited a marked difference in temperature optimum with respect to the temperate teleost Anguilla anguilla, the maximal activity rate occurring at approximately 0 degrees C for the former and 25 degrees C for the latter. Temperature dependence of icefish and eel intestinal mRNA-stimulated uptake in the heterologous system (oocytes) was comparable.