Relationship Between Diabetic Retinopathy Stages and Risk of Major Lower-Extremity Arterial Disease in Patients With Type 2 Diabetes.

OBJECTIVE: We evaluated the association between diabetic retinopathy stages and lower-extremity arterial disease (LEAD), its prognostic value, and the influence of potential contributors to this relationship in a prospective cohort of patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Diabetic retinopathy was staged at baseline as absent, nonproliferative, or proliferative. A Cox regression model was fitted in order to compute the hazard ratio (HR) (95% CI) for major LEAD (lower-limb amputation or revascularization) during follow-up by baseline retinopathy stages. The retinopathy-LEAD association was assessed in subgroups by age, sex, diabetes duration, HbA1c, systolic blood pressure, diabetic kidney disease, smoking, and macrovascular disease at baseline. The performance of retinopathy in stratifying LEAD risk was assessed by using the C statistic, integrated discrimination improvement (IDI), and net reclassification improvement (NRI). RESULTS: Among 1,320 participants without a history of LEAD at baseline, 94 (7.1%) developed a major LEAD during a 7.1-year median follow-up (incidence rate 9.6 per 1,000 person-years [95% CI 7.8-11.7]). The LEAD incidence rate (per 1,000 person-years) increased as retinopathy worsened: it was 5.5 (95% CI 3.9-7.8) in participants in whom retinopathy was absent, 14.6 (11.1-19.3) in those with nonproliferative retinopathy, and 20.1 (11.1-36.3) in those with proliferative retinopathy. Nonproliferative retinopathy (adjusted HR 2.31 [95% CI 1.43-3.81], P = 0.0006) and proliferative retinopathy (3.14 [1.40-6.15], P = 0.007) remained associated with major LEAD. No heterogeneity was observed across subgroups. Retinopathy enhanced the C statistic (+0.023 [95% CI 0.003-0.044], P = 0.02), IDI (0.209 [0.130-0.321], P < 0.001), and NRI (0.562 [0.382-0.799], P < 0.001) values for risk of LEAD, beyond traditional risk factors. CONCLUSIONS: An independent dose-response relationship was identified between diabetic retinopathy stages and major LEAD. Retinopathy yielded incremental prognostic information for stratifying risk of LEAD, suggesting its usefulness as a predictor of LEAD.

Monocytopenia, monocyte morphological anomalies and hyperinflammation characterise severe COVID-19 in type 2 diabetes.

Early in the COVID-19 pandemic, type 2 diabetes (T2D) was marked as a risk factor for severe disease and mortality. Inflammation is central to the aetiology of both conditions where variations in immune responses can mitigate or aggravate disease course. Identifying at-risk groups based on immunoinflammatory signatures is valuable in directing personalised care and developing potential targets for precision therapy. This observational study characterised immunophenotypic variation associated with COVID-19 severity in T2D. Broad-spectrum immunophenotyping quantified 15 leucocyte populations in peripheral circulation from a cohort of 45 hospitalised COVID-19 patients with and without T2D. Lymphocytopenia and specific loss of cytotoxic CD8+ lymphocytes were associated with severe COVID-19 and requirement for intensive care in both non-diabetic and T2D patients. A morphological anomaly of increased monocyte size and monocytopenia restricted to classical CD14Hi CD16- monocytes was specifically associated with severe COVID-19 in patients with T2D requiring intensive care. Increased expression of inflammatory markers reminiscent of the type 1 interferon pathway (IL6, IL8, CCL2, INFB1) underlaid the immunophenotype associated with T2D. These immunophenotypic and hyperinflammatory changes may contribute to increased voracity of COVID-19 in T2D. These findings allow precise identification of T2D patients with severe COVID-19 as well as provide evidence that the type 1 interferon pathway may be an actionable therapeutic target for future studies.

Comparison of a new versus standard removable offloading device in patients with neuropathic diabetic foot ulcers: a French national, multicentre, open-label randomized, controlled trial.

INTRODUCTION: The offloading is crucial to heal neuropathic diabetic foot ulcer (DFU). Removable offloading are the most used devices. Orthèse diabète is a new customized removable knee-high offloading device immobilizing foot and ankle joints, with some specific and innovative features that may improve offloading. We aimed to evaluate the efficiency of this device in DFU healing. RESEARCH, DESIGN AND METHODS: The evaluation of Offloading using a new removable ORTHOsis in DIABetic foot study is a French multicenter (13 centers) randomized controlled trial with blinded end points evaluation. Adults with neuropathic DFU were randomly assigned to either Orthèse Diabète (experimental device), or any type of conventional (usually used in France) removable offloading devices (control group). The primary outcome was the 3-month proportion of patients with fully healed DFU. RESULTS: Among 112 randomized patients (men 78%, age 62±10 years), the primary outcome occurred in 19 (33%) participants using conventional device vs 19 (35%) Orthèse Diabète users (p=0.79). Study groups were also comparable in terms of prespecified secondary end points including occurrence of new DFU (25% vs 27% in conventional and experimental groups), ipsilateral lower-limb amputation (4% vs 10%) or infectious complications (14% vs 13%) (p>0.05 for all). Adverse events were comparable between groups, including 4 deaths unrelated to study allocation (1 sudden death, 2 ventricular arrhythmias and 1 pancreatic cancer). Adverse events believed to be related to the device were higher in the Orthèse Diabète group than in the control group (15% vs 4%). Orthèse Diabète was less frequently worn than conventional devices (46% vs 66%, p=0.04). CONCLUSIONS: Orthèse Diabète, a new removable offloading orthosis immobilizing foot and ankle joints did not show superiority compared with conventional removable devices in neuropathic DFU healing and cannot be recommended to heal DFU. TRIAL REGISTRATION NUMBER: NCT01956162.

Glucagon revisited: Coordinated actions on the liver and kidney.

Glucagon secretion is stimulated by a low plasma glucose concentration. By activating glycogenolysis and gluconeogenesis in the liver, glucagon contributes to maintain a normal glycemia. Glucagon secretion is also stimulated by the intake of proteins, and glucagon contributes to amino acid metabolism and nitrogen excretion. Amino acids are used for gluconeogenesis and ureagenesis, two metabolic pathways that are closely associated. Intriguingly, cyclic AMP, the second messenger of glucagon action in the liver, is released into the bloodstream becoming an extracellular messenger. These effects depend not only on glucagon itself but on the actual glucagon/insulin ratio because insulin counteracts glucagon action on the liver. This review revisits the role of glucagon in nitrogen metabolism and in disposal of nitrogen wastes. This role involves coordinated actions of glucagon on the liver and kidney. Glucagon influences the transport of fluid and solutes in the distal tubule and collecting duct, and extracellular cAMP influences proximal tubule reabsorption. These combined effects increase the fractional excretion of urea, sodium, potassium and phosphates. Moreover, the simultaneous actions of glucagon and extracellular cAMP are responsible, at least in part, for the protein-induced rise in glomerular filtration rate that contributes to a more efficient excretion of protein-derived end products.

Lower extremity arterial disease in patients with diabetes: a contemporary narrative review.

Lower-extremity arterial disease (LEAD) is a major endemic disease with an alarming increased prevalence worldwide. It is a common and severe condition with excess risk of major cardiovascular events and death. It also leads to a high rate of lower-limb adverse events and non-traumatic amputation. The American Diabetes Association recommends a widespread medical history and clinical examination to screen for LEAD. The ankle brachial index (ABI) is the first non-invasive tool recommended to diagnose LEAD although its variable performance in patients with diabetes. The performance of ABI is particularly affected by the presence of peripheral neuropathy, medial arterial calcification, and incompressible arteries. There is no strong evidence today to support an alternative test for LEAD diagnosis in these conditions. The management of LEAD requires a strict control of cardiovascular risk factors including diabetes, hypertension, and dyslipidaemia. The benefit of intensive versus standard glucose control on the risk of LEAD has not been clearly established. Antihypertensive, lipid-lowering, and antiplatelet agents are obviously worthfull to reduce major cardiovascular adverse events, but few randomised controlled trials (RCTs) have evaluated the benefits of these treatments in terms of LEAD and its related adverse events. Smoking cessation, physical activity, supervised walking rehabilitation and healthy diet are also crucial in LEAD management. Several advances have been achieved in endovascular and surgical revascularization procedures, with obvious improvement in LEAD management. The revascularization strategy should take into account several factors including anatomical localizations of lesions, medical history of each patients and operator experience. Further studies, especially RCTs, are needed to evaluate the interest of different therapeutic strategies on the occurrence and progression of LEAD and its related adverse events in patients with diabetes.

Plasma copeptin, kidney disease, and risk for cardiovascular morbidity and mortality in two cohorts of type 2 diabetes.

BACKGROUND: Cardiovascular disease and kidney damage are tightly associated in people with type 2 diabetes. Experimental evidence supports a causal role for vasopressin (or antidiuretic hormone) in the development of diabetic kidney disease (DKD). Plasma copeptin, the COOH-terminal portion of pre-provasopressin and a surrogate marker of vasopressin, was shown to be positively associated with the development and progression of DKD. Here we assessed the association of plasma copeptin with the risk of cardiovascular events during follow-up in two prospective cohorts of type 2 diabetic patients, and we examined if this association could be mediated by deleterious effects of vasopressin on the kidney. METHODS: We studied 3098 and 1407 type 2 diabetic patients from the French cohorts DIABHYCAR and SURDIAGENE, respectively. We considered the incidence during follow-up (median: 5 years) of a combined end point composed of myocardial infarction, coronary revascularization, hospitalization for congestive heart failure, or cardiovascular death. Copeptin concentration was measured in baseline plasma samples by an immunoluminometric assay. RESULTS: The cumulative incidence of cardiovascular events during follow-up by sex-specific tertiles of baseline plasma copeptin was 15.6% (T1), 18.7% (T2) and 21.7% (T3) in DIABHYCAR (p = 0.002), and 27.7% (T1), 34.1% (T2) and 47.6% (T3) in SURDIAGENE (p < 0.0001). Cox proportional hazards survival regression analyses confirmed the association of copeptin with cardiovascular events in both cohorts: hazard ratio with 95% confidence interval for T3 vs. T1 was 1.29 (1.04-1.59), p = 0.02 (DIABHYCAR), and 1.58 (1.23-2.04), p = 0.0004 (SURDIAGENE), adjusted for sex, age, BMI, duration of diabetes, systolic blood pressure, arterial hypertension, HbA1c, total cholesterol, HDL-cholesterol, triglycerides, estimated glomerular filtration rate (eGFR), urinary albumin concentration (UAC), active tobacco smoking, and previous history of myocardial infarction at baseline. No interaction was observed between plasma copeptin and eGFR (p = 0.40) or UAC (p = 0.61) categories on the risk of cardiovascular events in analyses of pooled cohorts. CONCLUSIONS: Plasma copeptin was positively associated with major cardiovascular events in people with type 2 diabetes. This association cannot be solely accounted for by the association of copeptin with kidney-related traits.

Prognostic Values of Inflammatory and Redox Status Biomarkers on the Risk of Major Lower-Extremity Artery Disease in Individuals With Type 2 Diabetes.

OBJECTIVE: Inflammation and oxidative stress play an important role in the pathogenesis of lower-extremity artery disease (LEAD). We assessed the prognostic values of inflammatory and redox status biomarkers on the risk of LEAD in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: Plasma concentrations of tumor necrosis factor-α receptor 1 (TNFR1), angiopoietin-like 2, ischemia-modified albumin (IMA), fluorescent advanced glycation end products, protein carbonyls, and total reductive capacity of plasma were measured at baseline in the SURDIAGENE (Survie, Diabete de type 2 et Genetique) cohort. Major LEAD was defined as the occurrence during follow-up of peripheral revascularization or lower-limb amputation. RESULTS: Among 1,412 participants at baseline (men 58.2%, mean [SD] age 64.7 [10.6] years), 112 (7.9%) developed major LEAD during 5.6 years of follow-up. High plasma concentrations of TNFR1 (hazard ratio [95% CI] for second vs. first tertile 1.12 [0.62-2.03; P = 0.71] and third vs. first tertile 2.16 [1.19-3.92; P = 0.01]) and of IMA (2.42 [1.38-4.23; P = 0.002] and 2.04 [1.17-3.57; P = 0.01], respectively) were independently associated with an increased risk of major LEAD. Plasma concentrations of TNFR1 but not IMA yielded incremental information, over traditional risk factors, for the risk of major LEAD as follows: C-statistic change (0.036 [95% CI 0.013-0.059]; P = 0.002), integrated discrimination improvement (0.012 [0.005-0.022]; P < 0.001), continuous net reclassification improvement (NRI) (0.583 [0.294-0.847]; P < 0.001), and categorical NRI (0.171 [0.027-0.317]; P = 0.02). CONCLUSIONS: Independent associations exist between high plasma TNFR1 or IMA concentrations and increased 5.6-year risk of major LEAD in people with type 2 diabetes. TNFR1 allows incremental prognostic information, suggesting its use as a biomarker for LEAD.

Association of Circulating Biomarkers (Adrenomedullin, TNFR1, and NT-proBNP) With Renal Function Decline in Patients With Type 2 Diabetes: A French Prospective Cohort.

OBJECTIVE: We explored the prognostic value of three circulating candidate biomarkers-midregional-proadrenomedullin (MR-proADM), soluble tumor necrosis factor receptor 1 (sTNFR1), and N-terminal prohormone brain natriuretic peptide (NT-proBNP)-for change in renal function in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Outcomes were defined as renal function loss (RFL), ≥40% decline of estimated glomerular filtration rate (eGFR) from baseline, and rapid renal function decline (RRFD), absolute annual eGFR slope <-5 mL/min/year. We used a proportional hazard model for RFL and a logistic model for RRFD. Adjustments were performed for established risk factors (age, sex, diabetes duration, HbA1c, blood pressure, baseline eGFR, and urinary albumin-to-creatinine ratio [uACR]). C-statistics were used to assess the incremental predictive value of the biomarkers to these risk factors. RESULTS: Among 1,135 participants (mean eGFR 76 mL/min, median uACR 2.6 mg/mmol, and median GFR slope -1.6 mL/min/year), RFL occurred in 397, RRFD developed in 233, and 292 died during follow-up. Each biomarker predicted RFL and RRFD. When combined, MR-proADM, sTNFR1, and NT-proBNP predicted RFL independently from the established risk factors (adjusted hazard ratio 1.59 [95% CI 1.34-1.89], P < 0.0001; 1.33 [1.14-1.55], P = 0.0003; and 1.22 [1.07-1.40], P = 0.004, respectively) and RRFD (adjusted odds ratio 1.56 [95% CI 1.7-2.09], P = 0.003; 1.72 [1.33-2.22], P < 0.0001; and 1.28 [1.03-1.59], P = 0.02, respectively). The combination of the three biomarkers yielded the highest discrimination (difference in C-statistic = 0.054, P < 0.0001; 0.067, P < 0.0001 for RFL; and 0.027, P < 0.0001 for RRFD). CONCLUSIONS: In addition to established risk factors, MR-proADM, sTNFR1, and NT-proBNP improve risk prediction of loss of renal function in patients with type 2 diabetes.

Linkage disequilibrium with HLA-DRB1-DQB1 haplotypes explains the association of TNF-308G>A variant with type 1 diabetes in a Brazilian cohort.

BACKGROUND: A functional variant in the promoter region of the gene encoding tumor necrosis factor (TNF; rs1800629, -308G>A) showed to confer susceptibility to T1D. However, TNF rs1800629 was found, in several populations, to be in linkage disequilibrium with HLA susceptibility haplotypes to T1D. We evaluated the association of TNF rs1800629 with T1D in a cohort of Brazilian subjects, and assessed the impact of HLA susceptibility haplotypes in this association. METHODS: 659 subjects with T1D and 539 control subjects were genotyped for TNF-308G>A variant. HLA-DRB1 and HLA-DQB1 genes were genotyped in a subset of 313 subjects with T1D and 139 control subjects. RESULTS: Associations with T1D were observed for the A-allele of rs1800629 (OR 1.69, 95% CI 1.33-2.15, p<0.0001, in a codominant model) and for 3 HLA haplotypes: DRB1*03:01-DQB1*02:01 (OR 5.37, 95% CI 3.23-8.59, p<0.0001), DRB1*04:01-DQB1*03:02 (OR 2.95, 95% CI 1.21-7.21, p=0.01) and DRB1*04:02-DQB1*03:02 (OR 2.14, 95% CI 1.02-4.50, p=0.04). Linkage disequilibrium was observed between TNF rs1800629 and HLA-DRB1 and HLA-DQB1 alleles. In a stepwise regression analysis HLA haplotypes, but not TNF rs1800629, remained independently associated with T1D. CONCLUSION: Our results do not support an independent effect of allelic variations of TNF in the genetic susceptibility to T1D.

Association of serum concentration of TNFR1 with all-cause mortality in patients with type 2 diabetes and chronic kidney disease: follow-up of the SURDIAGENE Cohort.

OBJECTIVE: Renal dysfunction is a key risk factor for all-cause mortality in patients with type 2 diabetes (T2D). Circulating tumor necrosis factor receptor 1 (TNFR1) was recently suggested as a strong biomarker for end-stage renal failure in T2D. However, its relevance regarding all-cause death has yet to be conclusively established. We aimed to assess the prognostic value of serum TNFR1 concentration for all-cause death in T2D and diabetic kidney disease (DKD) from the SURDIAGENE (Survie, Diabete de type 2 et Genetique) study. RESEARCH DESIGN AND METHODS: A total of 522 T2D patients with DKD (estimated glomerular filtration rate [eGFR] <60 and/or urinary albumin-to-creatinine ratio [uACR] >30 mg/mmol) were followed for a median duration of 48 months, and 196 deaths occurred. RESULTS: Incidence rate (95% CI) for death increased as quartiles of TNFR1 concentration increased (first quartile: 4.7% patient-years [3.0-6.3%]; second quartile: 7.7% [5.4-10.0%]; third quartile: 9.3% [6.7-11.9%]; fourth quartile: 15.9% [12.2-19.5%]). In multivariate analysis taking age, diabetes duration, HbA1c, uACR, and eGFR into account, compared with the first quartile, patients from the fourth quartile had an adjusted hazard ratio for death of 2.98 (95% CI 1.70-5.23). The integrated discrimination improvement index was statistically significant when adding TNFR1 concentration to the UK Prospective Diabetes Study outcome equation (P = 0.031). CONCLUSIONS: TNFR1 is a strong prognostic factor for all-cause mortality in T2D with renal dysfunction, and its clinical utility is suggested in addition to established risk factors for all-cause mortality.

Glucose metabolism in 105 children and adolescents after pancreatectomy for congenital hyperinsulinism.

OBJECTIVE: To describe the long-term metabolic outcome of children with congenital hyperinsulinism after near-total or partial elective pancreatectomy. RESEARCH DESIGN AND METHODS: Patients (n = 105: 58 diffuse and 47 focal congenital hyperinsulinism) received operations between 1984 and 2006. Follow-up consisted of periodic measurements of pre- and postprandial plasma glucose over 24 h, OGTT, and IVGTT. Cumulative incidence of hypo- or hyperglycemia/insulin treatment was estimated by Kaplan-Meier analysis. RESULTS: After near-total pancreatectomy, 59% of children with diffuse congenital hyperinsulinism still presented mild or asymptomatic hypoglycemia that responded to medical treatments and disappeared within 5 years. One-third of the patients had both preprandial hypoglycemia and postprandial hyperglycemia. Hyperglycemia was found in 53% of the patients immediately after surgery; its incidence increased regularly to 100% at 13 years. The cumulative incidence of insulin-treated patients was 42% at 8 years and reached 91% at 14 years, but the progression to insulin dependence was very variable among the patients. Plasma insulin responses to IVGTT and OGTT correlated well with glycemic alterations. In focal congenital hyperinsulinism, hypoglycemia or hyperglycemia were rare, mild, and transient. CONCLUSIONS: Patients with focal congenital hyperinsulinism are cured of hypoglycemia after limited surgery, while the outcome of diffuse congenital hyperinsulinism is very variable after near-total pancreatectomy. The incidence of insulin-dependent diabetes is very high in early adolescence.

Two novel mutations in the EIF2AK3 gene in children with Wolcott-Rallison syndrome.

Wolcott-Rallison syndrome (WRS, OMIM 226980) is a rare autosomal recessive disorder characterized by permanent neonatal diabetes mellitus, epiphyseal dysplasia, and other multisystemic clinical manifestations. We described two novel mutations in the EIF2AK3 gene in two consanguineous families with WRS from Brazil and Morocco. We have observed in case 1 a homozygous C > T replacement at base pair c.1192 at exon 7, generating a stop codon at position 398 (Gln398Stop). Both of his parents were found to be heterozygous for the mutation. We detected in both parents of case 2, a deceased Moroccan girl, a duplication of base pair c.851A at exon 5 (c.851dupA) leading to a frameshift and a stop codon at position 285 (p.Pro285AlafsX3). Both cases 1 and 2 had neonatal diabetes mellitus, multiple epiphyseal dysplasia, and growth delay, and presented episodes of acute hepatic dysfunction. Case 1 presented central hypothyroidism, developmental delay, and mild mental retardation. Case 2 presented a fatal episode of acute renal failure. The clinical phenotype associated with the syndrome can be variable, but a combination of infancy-onset diabetes mellitus, multiple epiphyseal dysplasia, and hepatic and/or renal dysfunction is the mainstay of diagnosis.

HNF1α mutations are present in half of clinically defined MODY patients in South-Brazilian individuals / Mutações HNF1α estão presentes na metade dos pacientes da região sul do Brasil clinicamente diagnosticados com MODY

Maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes mellitus characterized by autosomal dominant inheritance, early age of onset, and pancreatic beta cell dysfunction. Heterozygous mutations in at least seven genes can cause MODY. In the present study we investigated the relative prevalence of GCK (glucokinase) and HNF1α (hepatocyte nuclear factor 1α) mutations, the more frequent causes of MODY, in 13 South-Brazilian families with multiple cases of diabetes consistent with MODY. Heterozygous variants in GCK and HNF1α genes were observed respectively in one (7.7 percent), and six (46.2 percent) families. The six HNF1α variants are likely to cause diabetes in the families where they were observed. However, we could not ascertain whether the GCK Gly117Ser variant found in one family is a causal mutation. In conclusion, we have confirmed in a South-Brazilian population that HNF1α mutations are a common cause of monogenic diabetes in adults selected with strict clinical diagnostic criteria.

O maturity-onset diabetes of the young (MODY) é uma forma monogênica de diabetes melito caracterizada por herança autossômica dominante, de instalação precoce, como disfunção da célula beta pancreática. Mutações heterozigotas em pelo menos sete genes causam MODY. No presente estudo, investigamos a prevalência relativa das mutações da GCK (glucokinase) e HNF1α (hepatocyte nuclear factor 1α), as causas mais freqüentes de MODY, em 13 famílias sul-brasileiras com múltiplos casos de diabetes consistentes com MODY. Variantes heterozigotas nos genes da GCK e HNF1α foram observadas, respectivamente, em uma (7,7 por cento) e em seis (46,2 por cento) famílias. As seis variantes do HNF1α provavelmente causaram o diabetes nas famílias nas quais foram observadas. No entanto, não se pode afirmar que a variante GCK Gly117Ser encontrada em uma família seja a mutação causal. Em conclusão, confirmamos que, em uma população do sul do Brasil, as mutações HNF1α são uma causa comum de diabetes monogênico em adultos selecionados com critérios clínicos diagnósticos estritos.

Glucose tolerance and insulin secretion, morbidity, and death in patients with cystic fibrosis.

OBJECTIVES: To describe the history, mechanisms, and consequences of cystic fibrosis (CF)-related diabetes, from childhood to early adulthood. STUDY DESIGN: Pancreatic beta-cell function was estimated from the plasma insulin/glucose ratios during oral glucose tolerance test (total area under the curve and deltaI(30-0min)/G(30min), homeostasis model assessment [HOMA]%B), insulin sensitivity with the HOMA%S index, in 237 children with CF (109 boys, 128 girls). Progression of glucose metabolism abnormalities was evaluated by analysis for interval censored data; rates of pulmonary transplantation and death by Kaplan-Meier analysis. RESULTS: Impaired glucose tolerance was found in 20% of patients at 10 years, 50% at 15 years, 75% at 20 years, 82% at 30 years; for diabetes, >20% at 15 year, 45% at 20 years, 70% at 30 years; for insulin treatment, 30% at 20 years, 40% at 30 years. Early impairment was associated with lower survival rates and higher rates of lung transplantation. The area under the curve(glucose) correlated with decreased body mass index and height. Decrease in early insulin secretion (deltaI(30-0min)/G(30min)) was associated with impaired glucose tolerance, in all estimates of insulin secretion with diabetes. HOMA%S did not differ between the groups. Increased inflammation correlated with insulin resistance and impaired glucose tolerance. CONCLUSIONS: CF-related diabetes, mainly because of beta-cell deficiency, is frequent early in life and associated with impaired nutritional state and growth, increased rates of terminal respiratory failure, and death.

Adiponectin gene and cardiovascular risk in type 2 diabetic patients: a review of evidences

Diabetic patients have a 3-fold higher risk of developing atherosclerosis and its clinical complications as compared to non-diabetic individuals. Part of the cardiovascular risk associated with diabetes is probably due to genetic determinants influencing both glucose homeostasis and the development of atherosclerosis. However, type 2 diabetes frequently coexists with other cardiovascular risk factors like arterial hypertension, central obesity and dyslipidemia. Genetic variability affecting many areas such as lipid and energy metabolisms, hypertension and haemodynamic mechanisms, blood clotting homeostasis, inflammation, and matrix turnover in the vascular wall will have an impact on the development of macrovascular complications in diabetic patients. Adiponectin is abundantly secreted by adipocytes. It plays important roles in lipid and glucose metabolisms and has direct anti-inflammatory and anti-atherogenic effects. In this review, we summarize recent data from the literature suggesting an implication of allelic variations of the adiponectin gene (ADIPOQ) in the genetic determinants of cardiovascular disease in diabetic subjects.

Os pacientes com diabetes apresentam risco três vezes maior de desenvolverem aterosclerose e suas complicações quando comparados a indivíduos sem hiperglicemia. Parte desse risco associado ao diabetes é provavelmente relacionado a determinantes genéticos que influenciam tanto a homeostase glicídica quanto o desenvolvimento da aterosclerose. Entretanto, o diabetes tipo 2 freqüentemente coexiste com outros fatores de risco cardiovascular, tais como hipertensão arterial, obesidade central e dislipidemia. A variabilidade genética interfere em várias áreas tais como o metabolismo lipídico, o metabolismo energético, hipertensão, mecanismos hemodinâmicos, mecanismos de coagulação, inflamação e na formação da matriz na parede vascular, que podem estar envolvidos nas complicações macrovasculares dos pacientes com diabetes. A adiponectina é secretada com abundância pelos adipócitos. Apresenta importante papel no metabolismo lipídico e glicídico, tendo ação direta tanto antiinflamatória quanto anti-aterogênica. Na atual revisão, nós resumimos os dados recentes da literatura que sugerem uma implicação de variantes alélicas do gene da adiponectina (ADIPOQ) que podem estar envolvidos na determinação genética da doença cardiovascular em indivíduos com diabetes.

Clinical spectrum associated with hepatocyte nuclear factor-1beta mutations.

BACKGROUND: Maturity-onset diabetes of the young type 5 (MODY5), a type of dominantly inherited diabetes mellitus and nephropathy, has been associated with mutations of the hepatocyte nuclear factor-1beta (HNF-1beta) gene, mostly generating truncated protein. Various phenotypes, including urogenital malformations, are related to HNF-1beta mutations. OBJECTIVE: To describe clinical and genetic findings in 13 patients with 8 novel HNF-1beta mutations. DESIGN: Multicenter, descriptive study. SETTING: 2 departments of diabetes, 1 department of internal medicine, and 1 department of nephrology. PARTICIPANTS: 8 probands with diabetes diagnosed before 40 years of age and nondiabetic kidney disease who were selected independent of their family history of diabetes, and 5 offspring. MEASUREMENTS: Characteristics of diabetes, renal function and structure, genital tract abnormalities, pancreas structure, insulin secretion, exocrine pancreas function, and liver test results. RESULTS: All mutations, including 5 missense changes, were found in the DNA-binding domain. Cosegregation of the mutation and MODY5 phenotype was observed in 4 families. Occurrence of a de novo mutation was demonstrated in 2 families. Diabetes was present in 10 of 13 mutation carriers. It was clinically overt in 5 participants and found by screening at age 19 to 38 years in 5 participants. Pancreas atrophy was observed in 5 of 6 probands, and pancreas exocrine insufficiency was observed in 6 of 7 probands. Renal involvement, consisting of structural changes and slowly progressive renal failure, was recognized in 9 patients at 18 to 41 years of age. Dysplastic kidneys were found by ultrasonography in 3 fetuses who subsequently showed transient neonatal renal failure. Genital tract abnormalities were present in 5 probands and liver enzyme levels were abnormal in 11 of 13 patients. LIMITATIONS: Since the study was small and not population-based, it could not estimate the prevalence of MODY5. Other phenotypes might be associated with HNF-1beta mutations. CONCLUSIONS: Maturity-onset diabetes of the young type 5 encompasses a wide clinical spectrum. Analysis for mutations of HNF-1beta is warranted, even without a family history of diabetes, in nonobese patients with diabetes and slowly progressive nondiabetic nephropathy, particularly when pancreatic atrophy or genital abnormalities are present.

Effect of a diabetic environment in utero on predisposition to type 2 diabetes.

BACKGROUND: Type 2 diabetes is affected by genetics and environmental factors. We aimed to assess the effect of an in-utero diabetic environment independently of the genetic background for type 2 diabetes. METHODS: We measured insulin sensitivity and insulin secretion in response to oral and intravenous glucose in 15 non-diabetic adult offspring of mothers with type 1 diabetes (exposed participants) and 16 offspring of type 1 diabetic fathers (controls). No participants had type 1 diabetes-associated autoantibodies. We also measured pancreatic polypeptide, a marker of parasympathetic drive to the pancreas. FINDINGS: There was no difference between the groups with respect to percent body fat and insulin sensitivity. Five of the 15 exposed participants, but none of the controls had impaired glucose tolerance (p=0.02). Early insulin secretion after an oral glucose tolerance test was lower in exposed participants than in controls: 8.6 IU/mmol (SD 5.4) in exposed participants with impaired glucose tolerance, 14.2 IU/mmol (6.5) in those with normal glucose tolerance and 17.7 IU/mmol (10.9) in controls (p=0.04). Mean insulin secretion rate during glucose infusion study was 4.7 pmol/kg per min (3.6) in people with impaired glucose tolerance, 5.5 pmol/kg per min (4.5) in exposed participants with normal glucose tolerance and 7.5 pmol/kg per min (6.1) in controls (p<0.0001). The area under the curve of pancreatic polypeptide 120 min after oral glucose ingestion was 1007 (429) in people with impaired glucose tolerance, 2829 (1701) in those with normal glucose tolerance, and 3224 (1352) in controls (p=0.04). INTERPRETATION: Exposure to a diabetic environment in utero is associated with increased occurrence of impaired glucose tolerance and a defective insulin secretory response in adult offspring, independent of genetic predisposition to type 2 diabetes. This insulin secretory defect could be related to low parasympathetic tone. Epidemiological studies are needed to confirm our observations before therapeutic strategies can be devised.

Bases genéticas do Diabetes Mellitus tipo 2 / Genetic bases of type 2 Diabetes Mellitus

A patogênese do diabetes mellitus tipo 2 (DM2) é complexa, associando fatores genéticos e fatores ambientais. A hiperglicemia é secundária à combinaçäo de defeitos tanto na sensibilidade à insulina quanto na disfunçäo das células a-pancreáticas. Vários estudos estabeleceram claramente a importância dos fatores genéticos na predisposiçäo ao DM2. No momento, conhecemos alguns genes implicados em formas monogênicas de diabetes (MODY, diabetes mitocondrial). No entanto, nas formas mais comuns da doença de caráter poligênico, conhecemos apenas poucos genes que säo associados à doença de uma forma reprodutível nos diferentes grupos populacionais estudados. Cada um destes poligenes apresenta um papel isolado muito pequeno, atuando na modulaçäo de fenótipos associados ao diabetes. Nestas formas tardias poligénicas de DM2 é evidente a importância dos fatores ambientais que modulam a expressäo clínica da doença. Nesta revisäo abordamos os avanços mais relevantes das bases genéticas do DM2.

Patologia molecular do receptor de sulfoniluréia (SUR1) / Molecular pathology of sulfonylurea receptor (SUR1)

O receptor de sulfoniluréia (SUR1) é uma subunidade dos canais de potássio ATP-dependentes expressos nas células beta pancreáticas. O papel deste receptor nos mecanismos de secreçäo da insulina foi bem demonstrado após a descriçäo de que mutaçöes no seu gene codificador säo responsáveis pela forma neonatal de hiperinsulinismo. O possível envolvimento de variantes deste gene na predisposiçäo genética ao diabetes mellitus tipo 2 também te sido estudado. Nesta revisäo discutimos os dados da literatura que abordam o envolvimento de altraçöes genéticas do SUR1 em patologias como o diabetes tipo 2, assim como nos mecanismos de secreçäo da insulina.