Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
5.
Diabet Med ; 33(7): 864-76, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26525806

RESUMO

The progressive nature of Type 2 diabetes necessitates treatment intensification over time in order to maintain glycaemic control, with many patients ultimately requiring insulin therapy. While insulin has unlimited potential efficacy, its initiation is often delayed and improvements in glycaemic control are typically accompanied by weight gain and an increased risk of hypoglycaemia, particularly as HbA1c approaches and falls below target levels. This may account for the sub-optimal control often achieved after insulin initiation. Combining insulin with antihyperglycaemic therapies that have a low risk of hypoglycaemia and are weight-neutral or result in weight loss is a therapeutic strategy with the potential to improve Type 2 diabetes management. Although the effects differ with each individual class of therapy, clinical trials have shown that adding a glucagon-like peptide-1 receptor agonist, dipeptidyl peptidase-4 inhibitor or sodium-glucose co-transporter-2 inhibitor to insulin regimens can offer a significant reduction in HbA1c without substantially increasing hypoglycaemia risk, or weight. The evidence and merit of each approach are reviewed in this paper. Once-daily co-formulations of a basal insulin and a glucagon-like peptide-1 receptor agonist have been developed (insulin degludec/liraglutide) or are under development (lixisenatide/insulin glargine). Insulin degludec/liraglutide phase III trials and a lixisenatide/insulin glargine phase II trial have shown robust HbA1c reductions, with weight loss and a low risk of hypoglycaemia. With insulin degludec/liraglutide now approved in Europe, an important consideration will be the types of patients who may benefit most from a fixed-ratio combination; this is discussed in the present review, and we also take a look toward future developments in the field.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Hipoglicemiantes/uso terapêutico , Incretinas/uso terapêutico , Insulina de Ação Prolongada/uso terapêutico , Liraglutida/uso terapêutico , Glicemia/metabolismo , Ensaios Clínicos como Assunto , Diabetes Mellitus Tipo 2/metabolismo , Combinação de Medicamentos , Quimioterapia Combinada , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/induzido quimicamente , Insulina/uso terapêutico , Insulina Glargina/uso terapêutico , Peptídeos/uso terapêutico , Transportador 2 de Glucose-Sódio , Inibidores do Transportador 2 de Sódio-Glicose
6.
Scand J Med Sci Sports ; 26(4): 404-12, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25919405

RESUMO

The aim of this study was to compare the glycemic and glucoregulatory hormone responses to low- and moderate-intensity morning resistance exercise (RE) sessions in type 1 diabetes (T1DM). Following maximal strength assessments (1RM), eight T1DM (HbA1C :72 ± 12 mmol/mol, age:34 ± 7 years, body mass index:25.7 ± 1.6 kg/m(2) ) participants attended the research facility on two separate occasions, having fasted and taken their usual basal insulin but omitting rapid-acting insulin. Participants performed six exercises for two sets of 20 repetitions at 30%1RM during one session [low-intensity RE session (LOW)] and two sets of 10 repetitions at 60%1RM during another session [moderate-intensity RE session (MOD)], followed by 65-min recovery. Sessions were matched for total mass lifted (kg). Venous blood samples were taken before and after exercise. Data (mean ± SEM) were analyzed using analysis of variance (P ≤ 0.05). There were no hypoglycemic occurrences throughout the study. Blood glucose rose similarly between sessions during exercise (P = 0.382), remaining comparable between sessions throughout recovery (P > 0.05). There was no effect of RE intensity on metabolic acidosis (P > 0.05) or peak growth hormone responses (P = 0.644), but a tendency for greater catecholamine responses under LOW (individualized peak concentrations: adrenaline MOD 0.55 ± 0.13 vs LOW 1.04 ± 0.37 nmol/L, P = 0.155; noradrenaline MOD 4.59 ± 0.86 vs LOW 7.11 ± 1.82 nmol/L, P = 0.082). The magnitude of post-exercise hyperglycemia does not differ between equal volume low and moderate intensity RE sessions performed in the morning.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Exercício Físico/fisiologia , Hiperglicemia/sangue , Treinamento Resistido , Adulto , Glicemia/análise , Epinefrina/sangue , Feminino , Hormônio do Crescimento/sangue , Humanos , Insulina/sangue , Interleucina-6/sangue , Masculino , Norepinefrina/sangue
7.
Diabet Med ; 31(8): 1009-13, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24702172

RESUMO

AIMS: To determine the influence of different volumes of resistance exercise on circulating interleukin-6 (IL-6) and to explore the relationships between IL-6 and glycaemia. METHODS: Eight participants with complication-free type 1 diabetes, whose mean ± SEM age was 38 (6) years, mean ± SEM HbA(1c) concentration was 71 ±11 mmol/mol (8.7 ±1.0%) and mean ± SEM type 1 diabetes duration was 15 ±13 years, attended the research facility after an overnight fast on four separate occasions, having administered their basal insulin the night before (glargine 27.5±3.1U, n=8), but omitted morning rapid-acting insulin. Participants completed either a one-set (14-min), two-set (28-min), or three-set (42-min) resistance exercise trial (eight exercises × 10 repetitions) at 67±3% one-repetition maximum followed by a 60-min recovery, or a resting control trial. Venous blood samples were taken before and after exercise. Data were analysed using repeated-measures ANOVA (P≤0.05). RESULTS: Whereas IL-6 levels remained similar to baseline levels after one set of resistance exercises (30 min, P=0.287; 60 min, P=0.318), IL-6 levels were > baseline levels at 60 min post-exercise after a two-set exercise trial (2.94 ± 0.94 pg/ml, P=0.002) and doubled at both 30 min (4.01 ± 1.00 pg/ml, P=0.048) and 60 min (4.28 ± 1.25 pg/ml, P=0.084) post-exercise after the three-set resistance exercise trial. Post-exercise blood glucose area under the curve (mmol/l/60 min) was greater after both the one-set (P=0.025) and two-set trials (P=0.008), than after the control trial, but similar between the three-set trial and the control trial (P=0.240). The rise in IL-6 from baseline to peak concentration significantly correlated inversely with blood glucose area under the curve (r=-0.65, P=0.041). CONCLUSIONS: Circulating IL-6 is increased by resistance exercise in a volume-dependent manner, and resistance exercise-induced increases in IL-6 correlated with reductions in post-exercise hyperglycaemia in type 1 diabetes, suggesting a role for IL-6 in improving post-resistance exercise glycaemic disturbances in type 1 diabetes.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Hiperglicemia/prevenção & controle , Interleucina-6/sangue , Músculo Esquelético/metabolismo , Treinamento Resistido , Regulação para Cima , Adulto , Glicemia/análise , Estudos de Coortes , Terapia Combinada , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Dieta para Diabéticos , Feminino , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemiantes/sangue , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/uso terapêutico , Insulina Glargina , Insulina de Ação Prolongada/sangue , Insulina de Ação Prolongada/farmacocinética , Insulina de Ação Prolongada/uso terapêutico , Masculino , Estudos Retrospectivos , Fatores de Tempo
10.
QJM ; 105(1): 3-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21920998

RESUMO

The management of diabetes during terminal illness is complex, with lack of agreement and consensus among physicians and multidisciplinary teams. Despite the plethora of guidelines available for the management of diabetes, there exists no agreed, evidence-based strategy for managing diabetes during terminal illness and at the end of life. A number of physiological factors may influence glycaemic control during terminal illness. These include anorexia, cachexia, malabsorption, renal and hepatic failure. Furthermore, controversy exists on the frequency of blood glucose monitoring, the optimum blood glucose range and how to achieve this. We review the factors influencing blood glucose during terminal illness and provide a suggested approach to managing patients with type 1 and type 2 diabetes during the early and late stages of terminal illness.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Neoplasias/complicações , Assistência Terminal/métodos , Doente Terminal , Algoritmos , Glicemia/metabolismo , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 2/complicações , Gastroenteropatias/etiologia , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Nefropatias/etiologia , Hepatopatias/etiologia , Educação de Pacientes como Assunto , Fatores de Risco
11.
Diabetes Res Clin Pract ; 94(2): 199-206, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21835486

RESUMO

AIM: To examine the effects of glibenclamide and repaglinide on glucose stimulated insulin release, incretins, oxidative stress and cell adhesion molecules in patients with type 2 diabetes suboptimally treated with metformin. METHODS: A randomized clinical trial was performed recruiting 27 subjects (HbA(1c) between 7.5 and 10.5%) free from cardiovascular and renal disease. Glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), total antioxidant status, F(2)-isoprostane, interleukin-6 and cell adhesion molecules were measured during an oral glucose load at baseline and after eight weeks of treatment. The areas under the curve were analysed at 45, 60 and 120 min (AUC(45), AUC(60), AUC(120)). RESULTS: Significant improvements in glucose were observed with repaglinide (HBA(1c): -1.5%, fasting glucose: -2.8 mmol/L, 2-h glucose: -3.7 mmol/L, AUC(120): -18.9%) and glibenclamide (-1.0%, -2.2 mmol/L, -2.5 mmol/L, -17.5%). Repaglinide was also associated with an increase in the AUC(60) and AUC(120) for insulin (+56%, +61%) and C-peptide (+41%, +36%). GLP-1, GIP, IL-6, ICAM-1 and E-selectin levels did not change in either group. No association was observed between GLP-1, GIP-1 and plasma markers of oxidative stress. CONCLUSION: Repaglinide is associated with improved postprandial glycaemic control via insulin and C-peptide release. We observed no direct effects of glibenclamide or repaglinide on plasma levels of GLP-1 or GIP. We observed no associations of GLP-1 and GIP with plasma markers of oxidative stress.


Assuntos
Glicemia/efeitos dos fármacos , Carbamatos/administração & dosagem , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glibureto/administração & dosagem , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Incretinas/sangue , Estresse Oxidativo/efeitos dos fármacos , Piperidinas/administração & dosagem , Adulto , Idoso , Análise de Variância , Biomarcadores/sangue , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Esquema de Medicação , Quimioterapia Combinada , Selectina E/sangue , F2-Isoprostanos/sangue , Feminino , Polipeptídeo Inibidor Gástrico/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Hemoglobinas Glicadas/metabolismo , Humanos , Hiperglicemia/sangue , Insulina/sangue , Molécula 1 de Adesão Intercelular/sangue , Interleucina-6/sangue , Masculino , Metformina/administração & dosagem , Pessoa de Meia-Idade , Período Pós-Prandial , Fatores de Tempo , Resultado do Tratamento , País de Gales
12.
Int J Clin Pract Suppl ; (167): 44-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20887303

RESUMO

AIM: To provide insight into clinical experience with liraglutide by reviewing four case studies of patients initiating liraglutide treatment. KEY FINDINGS: Liraglutide treatment was associated with clinically relevant reductions in glycated haemoglobin (HbA(1c.) ) levels. In two of three cases for which HbA(1c) information was available, patients achieved an HbA(1c) of 6.5% at 9-month follow-up and 6.1% at 12-month follow-up. In the third case, the HbA(1c) level was 7.5% at 18-month follow-up. Individuals treated with liraglutide also experienced clinically relevant weight reductions of 4-10%. Other non-glycaemic benefits of liraglutide treatment included reductions in blood pressure. There were no reported incidences of hypoglycaemia. Gastrointestinal adverse side effects were most commonly reported, including nausea, vomiting and dyspepsia; however, symptoms generally subsided during the first month of treatment. In one patient who had prolonged nausea with exenatide over 2 years, a treatment switch to liraglutide resulted in resolution of the nausea symptoms. CONCLUSIONS: Liraglutide treatment was associated with reductions in HbA(1c) levels as well as benefits beyond glycaemic control, such as weight loss and systolic blood pressure reductions. No hypoglycaemic episode was reported. Transient gastrointestinal adverse side effects were most commonly reported.


Assuntos
Diabetes Mellitus Tipo 2 , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/fisiopatologia , Substituição de Medicamentos , Exenatida , Peptídeo 1 Semelhante ao Glucagon/administração & dosagem , Peptídeo 1 Semelhante ao Glucagon/efeitos adversos , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Liraglutida , Prontuários Médicos , Monitorização Fisiológica , Peptídeos/administração & dosagem , Peptídeos/efeitos adversos , Peçonhas/administração & dosagem , Peçonhas/efeitos adversos , Vômito/induzido quimicamente
13.
Diabetes Res Clin Pract ; 90(2): 196-201, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20728955

RESUMO

Mitochondrial superoxide dismutase 2 (SOD2) is an endogenous anti-oxidant enzyme. The rs4880 gene variant results in a C>T substitution, influencing SOD enzymatic activity. This variant has been associated with micro- and macro-vascular complications in diabetes mellitus. Our aim was to examine the association between this variant and coronary heart disease (CHD) risk in a cross-sectional sample of subjects with diabetes. 776 Caucasian subjects with diabetes were genotyped. CHD risk, oxidised-LDL and plasma total anti-oxidant status (TAOS) were analysed in relation to genotype. In females, the TT genotype was associated with CHD (CC/CT/TT: No CHD vs. CHD: 22.4/56.0/21.6% vs. 12.0/50.0/38.0%, p=0.03; for CC/CT vs. TT, p=0.01). The odds ratio for CHD associated with the TT genotype compared to CC/CT was 2.22 [95%CI: 1.17-4.24], p=0.01. The TT genotype was also associated with significantly lower plasma TAOS. In males, no association was observed between genotype and CHD risk, but CHD was significantly associated with age, lower HDL, higher triglycerides, higher BMI and cigarette smoking. The TT genotype of this variant is associated with increased CHD risk and lower plasma anti-oxidant defences in females with diabetes. This modest genotype-effect is not apparent in males where traditional risk factors may play a greater role.


Assuntos
Doença das Coronárias/genética , Angiopatias Diabéticas/genética , Variação Genética , Polimorfismo de Nucleotídeo Único , Superóxido Dismutase/genética , Adulto , Idoso , Antioxidantes/metabolismo , Sequência de Bases , Doença das Coronárias/sangue , Doença das Coronárias/epidemiologia , Primers do DNA , Angiopatias Diabéticas/sangue , Angiopatias Diabéticas/epidemiologia , Etnicidade/genética , Feminino , Genótipo , Hemoglobinas Glicadas/metabolismo , Humanos , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , Grupos Raciais/genética , Medição de Risco , Caracteres Sexuais
14.
Prim Care Diabetes ; 4(1): 57-60, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20022310

RESUMO

Exenatide use in type 2 diabetes is limited in routine clinical practice. We examined a cross-section of 90 patients. Mean weight and HBA(1c) were 114.9+/-20.6 kg, 10.3+/-2.1% at initiation; 108.0+/-15.3 kg (p<0.0001), 9.0+/-2.1% (p<0.001) at 3 months; 109.2+/-18.2 kg (p<0.0001), 9.5+/-2.3% (p=0.08) at 6 months. Exenatide appears effective in reducing HBA(1c) and weight.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Peptídeos/uso terapêutico , Peçonhas/uso terapêutico , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Índice de Massa Corporal , Peso Corporal , Diabetes Mellitus Tipo 2/sangue , Quimioterapia Combinada , Exenatida , Hemoglobinas Glicadas/metabolismo , Humanos , Insulina/uso terapêutico , Compostos de Sulfonilureia/uso terapêutico , Resultado do Tratamento , Redução de Peso
15.
Curr Med Res Opin ; 25(2): 395-400, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19192984

RESUMO

OBJECTIVE: There is evidence that microalbuminuria and overt nephropathy may progress more slowly in long duration (> 20 years) type 1 diabetes (T1DM). To explore this further, we examined the characteristics of chronic kidney disease (CKD) in a large cohort of long duration T1DM in the United Kingdom (UK). RESEARCH DESIGN AND METHODS: We studied the UK 'Golden Years' cohort--a group of 400 patients from various parts of the UK with T1DM > 50 years duration. Demographic and clinical information were obtained. HbA(1c), lipids, creatinine and urinary albumin-creatinine ratio (ACR) were measured. Microalbuminuria was defined as 2.5-25.0 mg/mmol for males and 3.5-25.0 mg/mmol for females; macroalbuminuria was defined as an ACR > 25.0 mg/mmol for both sexes. RESULTS: Mean age was 69 years and duration of diabetes 55 years. Nine percent had macroalbuminuria and 27% microalbuminuria. No patient had stage 5 CKD. Microalbuminuria was associated significantly with increased diabetes duration (p = 0.02), male sex (p = 0.02), smoking (p = 0.002), higher HbA(1c) (p < 0.0001), raised triglycerides (p = 0.04), and peripheral vascular disease (PVD) (p < 0.0001). Macroalbuminuria had significant associations with smoking (p = 0.02), raised triglycerides (p = 0.01), raised creatinine (p = 0.02), PVD (p = 0.01) and hypertension (p = 0.01). CONCLUSIONS: We conclude that microalbuminuria and CKD are common, even at long duration (> 50 years) of T1DM, and have similar characteristics and associations as they do with shorter disease duration. There is a striking absence, however, of stage 5 CKD, but selection bias may be an important confounder since patients with advanced disease may have not survived.


Assuntos
Diabetes Mellitus Tipo 1/complicações , Falência Renal Crônica/complicações , Adolescente , Adulto , Criança , Cromatografia Líquida de Alta Pressão , Estudos de Coortes , Feminino , Humanos , Masculino , Reino Unido
16.
Diabet Med ; 20(10): 808-11, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14510860

RESUMO

BACKGROUND: Type 1 diabetes mellitus is associated with high levels of premature morbidity and mortality. Prolonged survival is possible, however, and some patients appear to be protected from the long-term complications of this condition. METHODS: Diabetes UK awards medals to patients who have had Type 1 diabetes for 50 years or more. By examining medal-holders, we have established the clinical and biochemical features of a group of 400 subjects (54% male) with Type 1 diabetes of long duration. RESULTS: Mean age of the subjects was 68.9 years and mean age-at-onset of diabetes 13.7 years. Features of long duration diabetes in this cohort include normal body mass (mean BMI 25.0 kg m-2), low insulin dose (mean 0.52 units kg-2) and greatly elevated HDL-cholesterol (mean 1.84 mmol/l). Mean HbA1c was 7.6% (normal range 3.8-5.0%) and no patient had a normal HbA1c at the time of venesection. As a group, they have long-lived parents and consume moderate amounts of alcohol. Medical contact has often been sporadic. A significant proportion (29%) were taking anti-hypertensive medication. Screening for micro- and macroalbuminuria was positive in 35.7%. CONCLUSIONS: Patients with long-duration (> 50 years) Type 1 diabetes are relatively protected from clinical diabetic nephropathy and large vessel disease; our data are consistent with protection possibly being genetically determined in part via elevated HDL-cholesterol levels. An abnormal urinary albumin/creatinine ratio is common in these patients, despite their low risk of significant renal deterioration; this may have implications for microalbuminuria screening programmes.


Assuntos
Diabetes Mellitus Tipo 1 , Idoso , Albuminúria/complicações , Doenças Cardiovasculares/complicações , Extração de Catarata , HDL-Colesterol/sangue , Creatinina/sangue , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/metabolismo , Retinopatia Diabética/complicações , Retinopatia Diabética/genética , Retinopatia Diabética/cirurgia , Feminino , Seguimentos , Genótipo , Hemoglobinas Glicadas/análise , Antígenos HLA-DR , Cadeias HLA-DRB1 , Humanos , Hipertensão/complicações , Insulina/uso terapêutico , Terapia a Laser , Longevidade , Masculino , Doenças da Glândula Tireoide/complicações , Triglicerídeos/sangue
17.
Diabetologia ; 46(3): 426-8, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12687343

RESUMO

AIMS/HYPOTHESIS: Susceptibility to diabetic nephropathy in subjects with Type 1 diabetes is mainly genetically determined. Excess cardiovascular risk associated with diabetes is overwhelmingly concentrated in patients with nephropathy. Endothelial dysfunction is a feature of cardiovascular disease, hypertension, dyslipidaemia and smoking, all of which are associated with diabetic nephropathy. Nitric oxide regulates endothelial function and so genes encoding nitric oxide synthases could confer susceptibility to nephropathy. Recently positive associations have been reported. We examined polymorphisms within NOS3 and NOS2A, the genes encoding endothelial- and inducible nitric oxide synthase, for association with nephropathy. METHODS: Large case-control studies of patients with Type 1 diabetes and overt nephropathy who had hypertension and diabetic retinopathy. The control group comprised Type 1 diabetic subjects who have been on insulin for 50 or more years and have an extremely low risk of nephropathy. Genotyping was by PCR and agarose- or automated polyacrylamide gel electrophoresis using fluorescence-labelled primers. RESULTS: NOS3 intron 4 genotype frequencies (n=860: 464 cases, 396 control subjects) were 2.6%, 23.3%, 74.1% and 2.3%, 22.7%, 75.0% for aa, ab and bb genotypes; p=0.935. NOS2A promoter genotype frequencies (n=715: 358 cases, 357 control subjects) were 0.3%, 16.8%, 83.0% and 0.3% 17.6% and 82.1% for +/+, +/- and -/- genotypes (p=0.952). CONCLUSION/INTERPRETATION: In our cohort of Caucasian subjects with Type 1 diabetes there is no association between either of the polymorphisms studied and diabetic nephropathy. The previous suggestion from smaller studies that the intron 4 polymorphism in NOS3 could play a role in susceptibility to the disease is not confirmed.


Assuntos
Nefropatias Diabéticas/enzimologia , Nefropatias Diabéticas/genética , Óxido Nítrico Sintase/genética , Polimorfismo Genético/genética , Alelos , DNA/genética , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/genética , Eletroforese em Gel de Ágar , Eletroforese em Gel de Poliacrilamida , Frequência do Gene , Genótipo , Humanos , Íntrons/genética , Óxido Nítrico Sintase Tipo II , Óxido Nítrico Sintase Tipo III , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Diabetes ; 50(1): 184-94, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11147786

RESUMO

Some immune system disorders, such as type 1 diabetes, multiple sclerosis (MS), and rheumatoid arthritis (RA), share common features: the presence of autoantibodies and self-reactive T-cells, and a genetic association with the major histocompatibility complex. We have previously published evidence, from 1,708 families, for linkage and association of a haplotype of three markers in the D18S487 region of chromosome 18q21 with type 1 diabetes. Here, the three markers were typed in an independent set of 627 families and, although there was evidence for linkage (maximum logarithm of odds score [MLS] = 1.2; P = 0.02), no association was detected. Further linkage analysis revealed suggestive evidence for linkage of chromosome 18q21 to type 1 diabetes in 882 multiplex families (MLS = 2.2; lambdas = 1.2; P = 0.001), and by meta-analysis the orthologous region (also on chromosome 18) is linked to diabetes in rodents (P = 9 x 10(-4)). By meta-analysis, both human chromosome 18q12-q21 and the rodent orthologous region show positive evidence for linkage to an autoimmune phenotype (P = 0.004 and 2 x 10(-8), respectively, empirical P = 0.01 and 2 x 10(-4), respectively). In the diabetes-linked region of chromosome 18q12-q21, a candidate gene, deleted in colorectal carcinoma (DCC), was tested for association with human autoimmunity in 3,380 families with type 1 diabetes, MS, and RA. A haplotype ("2-10") of two newly characterized microsatellite markers within DCC showed evidence for association with autoimmunity (P = 5 x 10(-6)). Collectively, these data suggest that a locus (or loci) exists on human chromosome 18q12-q21 that influences multiple autoimmune diseases and that this association might be conserved between species.


Assuntos
Doenças Autoimunes/genética , Cromossomos Humanos Par 18/genética , Ligação Genética/genética , Camundongos/genética , Ratos/genética , Animais , Artrite Reumatoide/genética , Mapeamento Cromossômico , Diabetes Mellitus Tipo 1/genética , Genes DCC/genética , Haplótipos , Humanos , Repetições de Microssatélites/genética , Esclerose Múltipla/genética , Fenótipo , Homologia de Sequência
19.
Ann Hum Genet ; 64(Pt 3): 215-21, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-11246473

RESUMO

Several studies have indicated that additional genes in the major histocompatibility complex (MHC) region, other than the class II genes HLA-DQB1 and -DRB1 (the IDDM1 locus), may contribute to susceptibility and resistance to type 1 diabetes. The relative magnitude of these non- DR/DQ effects is uncertain and their map location is unknown owing to the extraordinary linkage disequilibrium that extends over the 3.5 Mb of the MHC. The homozygous parent test has been proposed as a method for detection of additional risk factors conditional on HLA-DQB1 and -DRB1. However, this method is inefficient since it uses only parents homozygous for the primary disease locus, the DQB1-DRB1 haplotype. To overcome this limitation, Conditional ETDT was used in the present report to test for association conditional on the DQB1-DRB1 haplotype, thereby allowing all parents to be included in the analysis. First, we confirm in UK and Sardinian type 1 diabetic families that allelic variation at HLA-DRB1 has a very significant effect on the association of DQB1 and vice versa. The Conditional ETDT was then applied to the HLA TNF (tumour necrosis factor) region and microsatellite marker D6S273 region, both of which have been reported to contribute to IDDM1 independent of the HLA-DQB1-DRB1 genes. We found no evidence for a major role for either of these two regions in IDDM1.


Assuntos
Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença/genética , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Desequilíbrio de Ligação , Característica Quantitativa Herdável , Adolescente , Adulto , Alelos , Feminino , Testes Genéticos/métodos , Cadeias beta de HLA-DQ , Cadeias HLA-DRB1 , Haplótipos , Teste de Histocompatibilidade , Humanos , Masculino , Repetições de Microssatélites/genética , Fator de Necrose Tumoral alfa/genética
20.
Hum Mol Genet ; 5(7): 1075-80, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8817351

RESUMO

Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell-mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ-specific autoimmune disease.


Assuntos
Antígenos de Diferenciação/genética , Cromossomos Humanos Par 2/genética , Diabetes Mellitus Tipo 1/genética , Ligação Genética , Imunoconjugados , Abatacepte , Antígenos CD , Antígeno CTLA-4 , Estudos de Casos e Controles , Éxons/genética , Predisposição Genética para Doença , Doença de Graves/genética , Humanos , Núcleo Familiar , Mutação Puntual , Polimorfismo Genético
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA