Th17 pathway in recent-onset autoimmune diabetes.

AIMS: Evaluate the participation of IL-17 pathway in T1D pathogenesis. T helper 17 cells are potent, highly inflammatory cells that produce interleukin 17A (IL-17A), considered a mediator of various immune disorders. However, their role in Type 1 diabetes (T1D) pathogenesis in humans is not totally elucidated. METHODS: The expression of IL-17 Receptor A (IL-17RA) in peripheral T lymphocytes and IL-17A serum levels in recent-onset patients with T1D were compared with healthy controls. IL-17A gene variants were evaluated in a greater cohort. RESULTS: Patients with recent-onset T1D (less than 6 months of diagnosis) exhibited lower expression of IL-17RA in CD3+ T (% of cells = 31.3% × 43.6%; p = .041) and CD4+ T cells (11.1% × 25.2%; p = .0019) and lower number of IL-17RA in CD4+ T cells (MFI = 1.16 × 4.56; p = .03) than controls. IL-17RA expression in CD8+ T cells and IL-17A serum levels were similar in both groups. The coding regions and boundary intron sequences of IL17A were sequenced. Seventeen allelic variants, including three novel variants in exon 3 (3'UTR n) were identified, but no one was associated with T1D susceptibility, as well as the resulting haplotypes and diplotypes. The expression of IL-17RA was not correlated with metabolic variables (glucose and HbA1c levels) or pancreatic autoantibodies titers. CONCLUSIONS: The lower expression of IL-17RA in CD3+ and CD4+ T cells suggests a reduced effect of IL-17A in immune response of recent-onset T1D patients, at least at peripheral tissues. IL-17A allelic variants were not related with T1D susceptibility.

Importance of Zinc Transporter 8 Autoantibody in the Diagnosis of Type 1 Diabetes in Latin Americans.

There is a scarcity of data of zinc transporter-8 autoantibody (ZnT8A) on mixed populations such as Brazilian. Therefore, we evaluated the relevance of ZnT8A for type 1 diabetes (T1D) diagnosis and the role of ZnT8 coding gene (SLC30A8) in T1D predisposition. Patients with T1D (n = 629; diabetes duration = 11 (6-16) years) and 651 controls were genotyped for SLC30A8 rs16889462 and rs2466295 variants (BeadXpress platform). ZnT8 triple antibody was measured by ELISA; glutamic acid decarboxylase (GAD65A) and protein tyrosine phosphatase (IA-2A) autoantibodies by radioimmunoassay. RESULTS: Znt8A was detected in 68.7% of recent-onset T1D patients and 48.9% of the entire patient cohort, similar to GAD65A (68.3% and 47.2%) and IA-2A (64.8% and 42.4%) positivities respectively. ZnT8A was the only antibody in 8.4% of patients. Znt8A and IA2A frequencies and titers were independent of gender and ethnicity, whereas GAD65A titers were greater in females. The diabetes duration-dependent decline in ZnT8A frequency was similar to GAD65A and IA-2A. The SLC30A8 rs2466293 AG + GG genotypes were associated with T1D risk in non-European descents (56.2% × 42.9%; p = 0.018), and the GG genotype with higher ZnT8A titers in recent-onset T1D: 834.5 IU/mL (711.3-2190.0) × 281 IU/mL (10.7-726.8); p = 0.027. Conclusion ZnT8A detection increases T1D diagnosis rate even in mixed populations. SLC30A8 rs2466293 was associated with T1D predisposition in non-European descents.

The influence of population stratification on genetic markers associated with type 1 diabetes.

Ethnic admixtures may interfere with the definition of type 1 diabetes (T1D) risk determinants. The role of HLA, PTPN22, INS-VNTR, and CTLA4 in T1D predisposition was analyzed in Brazilian T1D patients (n = 915), with 81.7% self-reporting as white and 789 controls (65.6% white). The results were corrected for population stratification by genotyping 93 ancestry informative markers (AIMs) (BeadXpress platform). Ancestry composition and structural association were characterized using Structure 2.3 and STRAT. Ethnic diversity resulted in T1D determinants that were partially discordant from those reported in Caucasians and Africans. The greatest contributor to T1D was the HLA-DR3/DR4 genotype (OR = 16.5) in 23.9% of the patients, followed by -DR3/DR3 (OR = 8.9) in 8.7%, -DR4/DR4 (OR = 4.7) in 6.0% and -DR3/DR9 (OR = 4.9) in 2.6%. Correction by ancestry also confirmed that the DRB1*09-DQB1*0202 haplotype conferred susceptibility, whereas the DRB1*07-DQB1*0202 and DRB1*11-DQB1*0602 haplotypes were protective, which is similar to reports in African-American patients. By contrast, the DRB1*07-DQB1*0201 haplotype was protective in our population and in Europeans, despite conferring susceptibility to Africans. The DRB1*10-DQB1*0501 haplotype was only protective in the Brazilian population. Predisposition to T1D conferred by PTPN22 and INS-VNTR and protection against T1D conferred by the DRB1*16 allele were confirmed. Correcting for population structure is important to clarify the particular genetic variants that confer susceptibility/protection for T1D in populations with ethnic admixtures.

Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil.

OBJECTIVE: Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immunemediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied. METHODS: The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy. RESULTS: Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain. CONCLUSION: The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.

Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil

OBJECTIVE: Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immunemediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied. METHODS: The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy. RESULTS: Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain. CONCLUSION: The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.

Metformin, but not glimepiride, improves carotid artery diameter and blood flow in patients with type 2 diabetes mellitus.

OBJECTIVE: To compare the effects of glimepiride and metformin on vascular reactivity, hemostatic factors and glucose and lipid profiles in patients with type 2 diabetes. METHODS: A prospective study was performed in 16 uncontrolled patients with diabetes previously treated with dietary intervention. The participants were randomized into metformin or glimepiride therapy groups. After four months, the patients were crossed over with no washout period to the alternative treatment for an additional four-month period on similar dosage schedules. The following variables were assessed before and after four months of each treatment: 1) fasting glycemia, insulin, catecholamines, lipid profiles and HbA1 levels; 2) t-PA and PAI-1 (antigen and activity), platelet aggregation and fibrinogen and plasminogen levels; and 3) the flow indices of the carotid and brachial arteries. In addition, at the end of each period, a 12-hour metabolic profile was obtained after fasting and every 2 hours thereafter. RESULTS: Both therapies resulted in similar decreases in fasting glucose, triglyceride and norepinephrine levels, and they increased the fibrinolytic factor plasminogen but decreased t-PA activity. Metformin caused lower insulin and pro-insulin levels and higher glucagon levels and increased systolic carotid diameter and blood flow. Neither metformin nor glimepiride affected endothelial-dependent or endothelial-independent vasodilation of the brachial artery. CONCLUSIONS: Glimepiride and metformin were effective in improving glucose and lipid profiles and norepinephrine levels. Metformin afforded more protection against macrovascular diabetes complications, increased systolic carotid artery diameter and total and systolic blood flow, and decreased insulin levels. As both therapies increased plasminogen levels but reduced t-PA activity, a coagulation process was likely still ongoing.

Metformin, but not glimepiride, improves carotid artery diameter and blood flow in patients with type 2 diabetes mellitus

OBJECTIVE: To compare the effects of glimepiride and metformin on vascular reactivity, hemostatic factors and glucose and lipid profiles in patients with type 2 diabetes. METHODS: A prospective study was performed in 16 uncontrolled patients with diabetes previously treated with dietary intervention. The participants were randomized into metformin or glimepiride therapy groups. After four months, the patients were crossed over with no washout period to the alternative treatment for an additional four-month period on similar dosage schedules. The following variables were assessed before and after four months of each treatment: 1) fasting glycemia, insulin, catecholamines, lipid profiles and HbA1 levels; 2) t-PA and PAI-1 (antigen and activity), platelet aggregation and fibrinogen and plasminogen levels; and 3) the flow indices of the carotid and brachial arteries. In addition, at the end of each period, a 12-hour metabolic profile was obtained after fasting and every 2 hours thereafter. RESULTS: Both therapies resulted in similar decreases in fasting glucose, triglyceride and norepinephrine levels, and they increased the fibrinolytic factor plasminogen but decreased t-PA activity. Metformin caused lower insulin and pro-insulin levels and higher glucagon levels and increased systolic carotid diameter and blood flow. Neither metformin nor glimepiride affected endothelial-dependent or endothelial-independent vasodilation of the brachial artery. CONCLUSIONS: Glimepiride and metformin were effective in improving glucose and lipid profiles and norepinephrine levels. Metformin afforded more protection against macrovascular diabetes complications, increased systolic carotid artery diameter and total and systolic blood flow, and decreased insulin levels. As both therapies increased plasminogen levels but reduced t-PA activity, a coagulation process was likely still ongoing.

Carbohydrate supplementation increases intramyocellular lipid stores in elite runners.

The objective was to determine the effects of carbohydrate (CHO) supplementation on exercise-induced hormone responses and post-training intramyocellular lipid stores (IMCL). Twenty-four elite male athletes (28.0±1.2 years) were randomized to receive CHO (maltodextrin solution) or zero energy placebo solution (control group). The high-intensity running protocol consisted of 10×800 m at 100% of the best 3000-m speed (Vm3 km) and 2×1000 m maximal bouts in the morning and a submaximal 10-km continuous easy running in the afternoon of day 9. IMCL concentrations were assessed by (1)H-MRS before (-day 9) and after training (day 9) in soleus (SO) and tibialis anterior (TA) muscles. Blood hormones were also measured before, during, and post-exercise. The percent change (Δ%) in TA-IMCL was higher in the CHO group (47.9±24.5 IMCL/Cr) than in the control group (-1.7±13.1, respectively) (P=.04). Insulin concentrations were higher in the CHO group post-intermittent running compared to control (P=.02). Circulating levels of free fatty acids and GH were lower in the CHO group (P>.01). The decline in performance in the 2nd 1000-m bout was also attenuated in this group compared to control (P<.001 and P=.0035, respectively). The hormonal milieu (higher insulin and lower GH levels) in the CHO group, together with unchanged free fatty acid levels, probably contributed to the increased IMCL stores. This greater energy storage capacity may have improved post-exercise recovery and thus prevented performance deterioration.

Adipose tissue at the crossroads in the development of the metabolic syndrome, inflammation and atherosclerosis.

The authors analyze insulin resistance, the metabolic syndrome and endothelial dysfunction as consequence of a common antecedent, a low grade inflammation, indicating that in obesity there is a chronically activated inflammatory state of the adipose tissue. Furthermore, the inflammatory signaling is discussed according to the adipose tissue depot, visceral or subcutaneous.

Adipose tissue at the crossroads in the development of the metabolic syndrome, inflammation and atherosclerosis / Tecido adiposo na encruzilhada no desenvolvimento da síndrome metabólica, inflamação e aterosclerose

The authors analyze insulin resistance, the metabolic syndrome and endothelial dysfunction as consequence of a common antecedent, a low grade inflammation, indicating that in obesity there is a chronically activated inflammatory state of the adipose tissue. Furthermore, the inflammatory signaling is discussed according to the adipose tissue depot, visceral or subcutaneous.

Os autores analisam a resistência à insulina, a síndrome metabólica e a disfunção endotelial como consequência de um antecedente comum, a inflamação de baixo nível, o que mostra que a obesidade é um estado inflamatório cronicamente ativado do tecido adiposo. Discute-se, aqui, a sinalização inflamatória de acordo com a localização do tecido adiposo subcutâneo ou visceral.

[Genetic and humoral autoimmunity markers of type 1 diabetes: from theory to practice]. / Marcadores genéticos e auto-imunes do diabetes melito tipo 1: da teoria para a prática.

Type 1 A diabetes mellitus (T1AD) results from the autoimmune destruction of the insulin producing pancreatic beta-cells. The largest contribution to genetic susceptibility comes from several genes located in the major histocompatibility complex on chromosome 6p21.3 (IDDM1 locus), accounting for at least 40% of the family aggregation of this disease. The highest-risk human leukocyte antigen HLA genotype for T1AD is DR3-DQA1*0501-DQB1*0201/DR4-DQA1*0301-DQB1*0302, whereas -DR15-DQA1*0102-DQB1*0602 haplotype is associated with dominant protection. Three other T1D loci associated with predisposition are the Variable Number for Tandem Repeats (VNTR) near the insulin gene (IDDM2), which accounts to 10% of genetic susceptibility, the Cytotoxic T-Lymphocyte-associated Antigen (CTLA-4)(IDDM 12) and the Protein Tyrosine Phosphatasis Nonreceptor-type 22 (PTPN22). Many other gene suspected to predispose to autoimmunity have been investigated. T1AD is frequently associated with autoimmune thyroid disease, celiac disase, Addison s disease and many other autoimmune diseases, characterized by organ-specific autoantibodies and related to the same genetic background. Using these autoantibodies, organ specific autoimmunity may be detected before the development of clinical disease preventing significant morbidity.

Marcadores genéticos e auto-imunes do diabetes melito tipo 1: da teoria para a prática: [revisão] / Genetic and humoral autoimmunity markers of type 1 diabetes: from theory to practice: [review]

O diabetes melito tipo 1 auto-imune (DM1A) resulta da destruição auto-imune seletiva das células-beta pancreáticas produtoras de insulina. O principal determinante genético de suscetibilidade para o DM1A está em genes do complexo principal de histocompatibilidade, no cromossomo 6p211.3 (locus IDDM1), responsável por 40 por cento ou mais da agregação familiar dessa doença. O maior risco é conferido pelo genótipo do antígeno leucocitário humano HLA-DR3-DQA1* 0501-DQB1*0201/DR4-DQA1*0301-QB1*0302, e o haplótipo HLA-DR15-DQA1* 0102-DQB1*0602 é associado à proteção. Três outros loci relacionados à predisposição a DM1A são o número variável de freqüências repetidas (VNTR) do gene da insulina (IDDM2), que confere 10 por cento da suscetibilidade genética, o antígeno-4 associado ao linfócito T citotóxico (CTLA-4) e o protein tyrosine phosphatasis nonreceptor-type 22 (PTPN22). Muitos outros genes suspeitos de predispor à auto-imunidade estão sendo investigados. O DM1A é freqüentemente associado com doença auto-imune tiroidiana, doença celíaca, doença de Addison e várias outras doenças auto-imunes, caracterizadas por auto-anticorpos órgãos-específicos, relacionados aos mesmos determinantes genéticos. Esses anticorpos são úteis na detecção de auto-imunidade órgão-específica antes do aparecimento da doença clínica, prevenindo comorbidades.

Type 1 A diabetes mellitus (T1AD) results from the autoimmune destruction of the insulin producing pancreatic beta-cells. The largest contribution to genetic susceptibility comes from several genes located in the major histocompatibility complex on chromosome 6p21.3 (IDDM1 locus), accounting for at least 40 percent of the family aggregation of this disease. The highest-risk human leukocyte antigen HLA genotype for T1AD is DR3-DQA1*0501-DQB1*0201/DR4-DQA1*0301-DQB1*0302, whereas -DR15-DQA1*0102-DQB1*0602 haplotype is associated with dominant protection. Three other T1D loci associated with predisposition are the Variable Number for Tandem Repeats (VNTR) near the insulin gene (IDDM2), which accounts to 10 percent of genetic susceptibility, the Cytotoxic T-Lymphocyte-associated Antigen (CTLA-4)(IDDM 12) and the Protein Tyrosine Phosphatasis Nonreceptor-type 22 (PTPN22). Many other gene suspected to predispose to autoimmunity have been investigated. T1AD is frequently associated with autoimmune thyroid disease, celiac disase, Addison´s disease and many other autoimmune diseases, characterized by organ-specific autoantibodies and related to the same genetic background. Using these autoantibodies, organ specific autoimmunity may be detected before the development of clinical disease preventing significant morbidity.

How much information do medical practitioners and endocrinologists have about diabetic retinopathy?

OBJECTIVE: The objective of this study was to use a questionnaire to evaluate knowledge concerning diabetic retinopathy among the physicians present at the 12th Latin American Congress on Diabetes held in São Paulo, Brazil, September 2004. METHODS: A questionnaire about their experience and management of patients with diabetes mellitus and the ophthalmologic examination was administered to 168 endocrinologists attending the meeting. RESULTS: Among the 168 physicians, only 36.9 percent correctly referred patients with diabetes type 1 to an ophthalmologist, whereas 86.9 percent referred patients with the type 2 disorder as recommended by the American Academy of Ophthalmology. Regarding the correct indication for screening for diabetic retinopathy, more physicians who had received their degree less than 5 years previously implemented this practice (54.8 percent), as opposed to those who had received their MD 20 years or more ago (22.6 percent). Regarding their experience in funduscopy during their specialty training, 52.4 percent claimed to have experience, but only 21.4 percent of those interviewed performed this examination on their patients. According to 84.5 percent of the interviewees, the fundus examination influenced their clinical treatment program. CONCLUSION: Our study demonstrates that medical knowledge among medical practitioners and endocrinologists on preventive measures and periodicity of diabetic retinopathy examinations appears to be far from ideal for diabetes type 1, but satisfactory for diabetes type 2. Therefore, refresher courses emphasizing the correct management of diabetic patients are necessary, because the social and economic impact of retinopathy is significant.

OBJETIVO: O objetivo deste estudo foi avaliar através de questionário o conhecimento dos médicos presentes no 12° Congresso Latino Americano de Diabetes Realizado em São Paulo Brasil, Setembro de 2004. MATERIAIS E MÉTODOS: Através de um questionário aplicado a 168 especialistas em endocrinologia presentes no 12° Congresso Latino Americano de Diabetes realizado São Paulo - Brasil em Setembro de 2004, os autores interrogaram sobre a experiência e conduta em relação à Retinopatia Diabética e ao exame oftalmológico. RESULTADOS: Dos 168 médicos, apenas 36,9 por cento encaminhavam corretamente ao oftalmologista os pacientes com diabetes do tipo 1, enquanto 86,9 por cento o faziam de acordo com a Academia Americana de Oftalmologia para os diabéticos do tipo 2. Quanto ao correto encaminhamento dos pacientes para exame de fundo de olho: os médicos com tempo de formação inferior a cinco anos foram os que mais realizam esta prática (54,8 por cento), comparados àqueles com 20 ou mais anos (22,1 por cento). Quanto à experiência em fundoscopia durante a especialização, embora 52,40 por cento afirmassem possuir experiência, apenas 21,4 por cento dos entrevistados realizavam fundo de olho em seus pacientes. Para 84,5 por cento dos entrevistados, o exame de fundo de olho influenciava o tratamento clínico sistemico. CONCLUSÃO: O estudo demonstra que o conhecimento médico das medidas preventivas e de periodicidade do exame da Retinopatia Diabética apresenta-se distante do ideal, para diabéticos tipo 1 e satisfatória para diabéticos tipo 2. Médicos graduados ate 5 anos apresentaram maior porcentagem de correto encaminhamento. A presença de retinopatia diabética no exame de fundo de olho influencia o tratamento clinico sistêmico da maioria dos médicos entrevistados.

Diabetes Mellitus tipo 2 / Type 2 diabetes mellitus

Atualizaçäo no tratamento do diabetes mellitus tipo 2: dieta, exercícios, novas drogas, importancia da associaçäo de medicamentos para o controle adequado e prevençäo de complicaçöes crônicas.(au)

Uso de bloqueadores beta-adrenérgicos em pacientes diabéticos / Beta-blockers in diabetic patients

Betabloqueadores eram tradicionalmente contra indicados em pacientes diabéticos pelo efeito potencial de piora da tolerância à glicose, resistência à insulina, metabolismo lipídico e risco de mascarar e retardar o retorno de episódio hipoglicêmico.Entretanto, seus efeitos cardioprotetores podem ser vantajosos nesses pacientes com risco aumentado para doença cardiovascular.Os betabloqueadores aumentam a sobrevida pós-infarto, melhoram a funçäo ventricular na insuficiência cardíaca e controlam a pressäo arterial e as arritmias.Os efeitos deletérios podem ser minimizados utilizando-se preferencialmente as drogas cardiosseletivas ou de terceira geraçäo em dose baixas.

Micro ITT para avaliar sensibilidade tecidual à insulina / Micro ITT to evaluate tissue sensitivity to insulin

Padronizamos prova de sensibilidade tecidual à açäo da insulina exógena in vivo, baseada na queda glicêmica precoce (período de cinco a 15 minutos após a injeçäo de insulina), utilizando insulina em baixa dose (0,025U/Kg de peso corpóreo - 1/4 da dose usual) para prevenir hipoglicemia severa e precoce e a conseqüente liberaçäo de hormônios contra-reguladores, como por exemplo o hormônio de crescimento (GH). A constante de desaparecimento da glicose no plasma (Kg) foi maior no grupo-controle normal quando comparada com o grupo obeso diabético (obeso ou de peso normal) ou pacientes com acromegalia, hipercortisolismo e lipodistrofia diabética (p<0,05). O Kg no grupo obeso também foi maior que no grupo obeso diabético (p<0,05). Näo houve elevaçäo significante nos níveis de GH. Concluímos que a avaliaçäo da sensibilidade à açäo da insulina exógena através do Micro ITT, medindo a queda glicêmica precoce, é um método prático e fidedigno, permitindo a diferenciaçäo entre pacientes normais e pacientes portadores de patologias com resistência à açäo hormonal, podendo esta prova ser utilizada em diagnóstico e pesquisa clínica