Manuel Aguilar-Diosdado

Nitric Oxide Is a Mediator of Antiproliferative Effects Induced by Proinflammatory Cytokines on Pancreatic Beta Cells

Nitric oxide (NO) is involved in several biological processes. In type 1 diabetes mellitus (T1DM), proinflammatory cytokines activate an inducible isoform of NOS (iNOS) in β cells, thus increasing NO levels and inducing apoptosis. The aim of the current study is to determine the role of NO (1) in the antiproliferative effect of proinflammatory cytokines IL-1β, IFN-γ, and TNF-α on cultured islet β cells and (2) during the insulitis stage prior to diabetes onset using the Biobreeding (BB) rat strain as T1DM model. Our results indicate that NO donors exert an antiproliferative effect on β cell obtained from cultured pancreatic islets, similar to that induced by proinflammatory cytokines. This cytokine-induced antiproliferative effect can be reversed by L-NMMA, a general NOS inhibitor, and is independent of guanylate cyclase pathway. Assays using NOS isoform specific inhibitors suggest that the NO implicated in the antiproliferative effect of proinflammatory cytokines is produced by inducible NOS, although not in an exclusive way. In BB rats, early treatment with L-NMMA improves the initial stage of insulitis. We conclude that NO is an important mediator of antiproliferative effect induced by proinflammatory cytokines on cultured β cell and is implicated in β-cell proliferation impairment observed early from initial stage of insulitis.

Evaluación del grado de consecución de objetivos de control metabólico en pacientes con diabetes mellitus tipo 2

OBJECTIVE To evaluate the extent to which metabolic targets in type 2 diabetes (DM-2) are achieved in the Endocrinology and Clinical Nutrition Unit of the Hospital Puerta del Mar in Cadiz (Spain) from 2005 to 2008. METHOD The database included in the computer application HP-Doctor used for all patients attended in our unit (admissions, consultations and peripheral centers) was analyzed. All patients with a principal or secondary diagnosis of DM-2 were included. Clinical characteristics, chronic complications, drug treatment and the percentage of patients who achieved annual mean targets of glycosylated hemoglobin (HbA1c) and low-density lipoprotein cholesterol (LDLc) were analyzed. RESULTS From 2005 to 2008, the number of DM-2 patients with computerized records increased by 108.7%. In 2008, 1,177 patients were evaluated. A total of 10.8% were active smokers, 53% had hypertension, and 51.2% and 12.6% presented with retinopathy and cardiovascular disease, respectively. During the study period, the percentage of patients with a mean HbA1c <7% was similar (2005: 31.7% 2008: 30.4%), those with LDLc <100 mg/dl increased from 19.2% to 25.6% and only 9.2% of patients achieved both targets, HbA1c <7% and LDLc <100 mg/dl. CONCLUSIONS In 2008, only 30% of DM-2 patients achieved a mean HbA1c < 7% and only 25% had LDLc < 100 mg/dl. Metabolic control in DM-2 patients should be improved.

Adipokines and metabolic syndrome risk factors in women with previous gestational diabetes mellitus

Gestational diabetes mellitus (GDM) has been recognized as a significant risk factor for metabolic syndrome and CVD. The aim of the study was to evaluate the relationships between levels of cytokines, components of metabolic syndrome and cardiovascular risk markers in women with previous gestational diabetes.

Es posible alcanzar en la práctica clínica los objetivos de control metabólico establecidos para pacientes con diabetes mellitus tipo 1

Objetivo Evaluar el grado de consecucion de indicadores de calidad de atencion en pacientes con diabetes mellitus tipo 1 (DM1) atendidos en la Unidad de Gestion Clinica (UGC) de Endocrinologia y Nutricion del Hospital Puerta del Mar de Cadiz. Metodologia Explotacion de la base de datos incluida en la aplicacion informatica HP-Doctor utilizada para todos los pacientes atendidos en la UGC (hospitalizacion, consultas y centros perifericos). Se incluye a todos los pacientes con diagnostico principal o secundario de DM1. Los indicadores de calidad analizados han sido seleccionados de las principales guias de practica clinica de atencion a pacientes con diabetes. Resultados Se analiza una amplia cohorte de pacientes con DM1 (489 pacientes) en seguimiento por nuestra UGC desde 2005 a 2007. En el periodo estudiado, el valor medio de glucohemoglobina (HbA 1c ) mejoro del 7,78 al 7,36%; se incremento el porcentaje de pacientes con HbA 1c media menor del 7% desde el 24,6 hasta el 27,1%, y disminuyo del 42,6 hasta el 38,7% el porcentaje de pacientes con HbA 1c media superior al 8%. En el ano 2007, tan solo un 35,5% de los pacientes mantenian cifras medias de colesterol de las lipoproteinas de baja densidad menores de 100 mg/dl. Conclusiones A pesar de la mejora obtenida en los parametros de control metabolico, la mayoria de los pacientes con DM1 en seguimiento por nuestra unidad mantienen un inadecuado control glucemico y lipidico.

Use of Sensors in the Treatment and Follow-up of Patients with Diabetes Mellitus

Glucose control is the cornerstone of Diabetes Mellitus (DM) treatment. Although self-regulation using capillary glycemia (SRCG) still remains the best procedure in clinical practice, continuous glucose monitoring systems (CGM) offer the possibility of continuous and dynamic assessment of interstitial glucose concentration. CGM systems have the potential to improve glycemic control while decreasing the incidence of hypoglycemia but the efficiency, compared with SRCG, is still debated. CGM systems have the greatest potential value in patients with hypoglycemic unawareness and in controlling daily fluctuations in blood glucose. The implementation of continuous monitoring in the standard clinical setting has not yet been established but a new generation of open and close loop subcutaneous insulin infusion devices are emerging making insulin treatment and glycemic control more reliable.

Parámetros analíticos en el paciente con diabetes mellitus

Actualmente existen numerosas pruebas de laboratorio para el diagnostico y el seguimiento de los pacientes con diabetes mellitus:determinacion de glucemia en ayunas y posprandial, autoanalisis de glucemia capilar, presencia de cuerpos cetonicos, hemoglobina glucosilada y fructosamina, microalbuminuria y determinacion de marcadores geneticos y de autoinmunidad. La evidencia cientifica que respalda cada una de ellas varia sustancialmente y las guias de practica clinica proporcionan las recomendaciones con mayor soporte cientifico junto con otras basadas tan solo en consensos de expertos. En este trabajo se revisan las determinaciones de laboratorio mas importantes en diabetes mellitus y se evalua su grado de evidencia cientifica.

The type 2 diabetes-associated HMG20A gene is mandatory for islet beta cell functional maturity

HMG20A (also known as iBRAF) is a chromatin factor involved in neuronal differentiation and maturation. Recently small nucleotide polymorphisms (SNPs) in the HMG20A gene have been linked to type 2 diabetes mellitus (T2DM) yet neither expression nor function of this T2DM candidate gene in islets is known. Herein we demonstrate that HMG20A is expressed in both human and mouse islets and that levels are decreased in islets of T2DM donors as compared to islets from non-diabetic donors. In vitro studies in mouse and human islets demonstrated that glucose transiently increased HMG20A transcript levels, a result also observed in islets of gestating mice. In contrast, HMG20A expression was not altered in islets from diet-induced obese and pre-diabetic mice. The T2DM-associated rs7119 SNP, located in the 3′ UTR of the HMG20A transcript reduced the luciferase activity of a reporter construct in the human beta 1.1E7 cell line. Depletion of Hmg20a in the rat INS-1E cell line resulted in decreased expression levels of its neuronal target gene NeuroD whereas Rest and Pax4 were increased. Chromatin immunoprecipitation confirmed the interaction of HMG20A with the Pax4 gene promoter. Expression levels of Mafa, Glucokinase, and Insulin were also inhibited. Furthermore, glucose-induced insulin secretion was blunted in HMG20A-depleted islets. In summary, our data demonstrate that HMG20A expression in islet is essential for metabolism-insulin secretion coupling via the coordinated regulation of key islet-enriched genes such as NeuroD and Mafa and that depletion induces expression of genes such as Pax4 and Rest implicated in beta cell de-differentiation. More importantly we assign to the T2DM-linked rs7119 SNP the functional consequence of reducing HMG20A expression likely translating to impaired beta cell mature function.

Unfavorable cytokine and adhesion molecule profiles during and after pregnancy, in women with gestational diabetes mellitus

espanolAntecedentes La diabetes mellitus gestacional es un factor de riesgo importante para el sindrome metabolico y la enfermedad cardiovascular. Objetivos Se evaluaron las relaciones entre los componentes del sindrome metabolico, los niveles de citocinas y moleculas de adhesion en mujeres con diabetes gestacional durante el embarazo y en el posparto. Pacientes y metodos Estudio prospectivo de casos y controles. Se analizaron 126 mujeres gestantes (63 con diabetes mellitus gestacional y 63 controles). En el periodo posparto, se reevaluaron 41 casos y 21 controles. Se analizaron variables clinicas, niveles de citocinas y moleculas de adhesion durante las semanas 24-29 de la gestacion y 12 meses despues del parto. Resultados En el periodo posparto, el factor de necrosis tumoral alfa en casos y controles, y la adiponectina en controles fueron significativamente mas altos. Los casos mostraron mayores niveles de leptina, sin diferencias significativas durante el embarazo y despues del parto. No se observaron diferencias significativas en las moleculas de adhesion y la interleucina 6 entre casos y controles durante el periodo de embarazo y el posparto, pero ambos fueron mayores en los casos. Durante el embarazo y posparto, la adiponectina disminuyo en los casos y aumento en los controles. Observamos correlaciones positivas significativas entre adiponectina con glucemia en ayunas y moleculas de adhesion celular vascular-1, y entre leptina y factor de necrosis tumoral alfa. Conclusiones Los resultados indican que el aumento de la inflamacion y la hiperglucemia transitoria durante el embarazo representarian una forma latente de sindrome metabolico, con un mayor riesgo de diabetes mellitus tipo 2 y de enfermedad cardiovascular en el futuro. EnglishBackground Gestational diabetes mellitus is a significant risk factor for metabolic syndrome and cardiovascular disease. Aims To assess the relationships between components of the metabolic syndrome and cytokine and adhesion molecule levels in women with GDM during pregnancy and after delivery. Patients and methods A prospective case–control study on a sample of 126 pregnant women (63 with and 63 without gestational diabetes mellitus). In an intra-subject analysis, 41 women with history of gestational diabetes mellitus and 21 controls were re-assessed in the postpartum period. Clinical data and levels of cytokines and adhesion molecules were recorded during weeks 24–29 of pregnancy and 12 months after delivery. Results In the postpartum period, there were significantly higher levels of tumor necrosis factor alpha in both cases and controls, and of adiponectin in controls. Cases showed higher leptin levels, with no significant differences during and after pregnancy. No significant differences were seen in adhesion molecules and interleukin-6 between cases and controls during pregnancy and in the postpartum period, but levels of both were higher in cases. During pregnancy and after delivery, adiponectin decreased in cases and increased in controls. Significant positive correlations were seen between adiponectin and fasting blood glucose levels and vascular cell adhesion molecule-1, and also between leptin and tumor necrosis factor alpha levels. Conclusions The results suggest that increased inflammation and transient hyperglycemia during pregnancy would represent a latent form of metabolic syndrome, with an increased risk for type 2 diabetes mellitus and future cardiovascular disease.

Nocturnal blood pressure is associated with the progression of microvascular complications and hypertension in patients with type 1 diabetes mellitus

AIMS To evaluate relationships between early alterations in blood pressure and the progression of microvascular complications of diabetes in clinically-normotensive patients with type 1 diabetes (T1DM). METHODS In a prospective observational study of 85 normotensive T1DM patients without microalbuminuria, blood pressure (BP) was monitored over 24h using the ambulatory blood pressure monitoring (ABPM) system at baseline and 7years later. Development or progression of microalbuminuria, retinopathy and hypertension was evaluated. RESULTS Initially, 20 patients (24%) were diagnosed with masked hypertension and 31 (37%) with non-dipper pattern as the only pathological findings. At 7years: 1) twenty-seven patients (32%) had progression of retinopathy related to the nocturnal diastolic blood pressure (BPD) (OR:1.122; p=0.034) and final non-dipper pattern (OR:5.857; p=0.005); 2) seven patients (10%) developed microalbuminuria for which nocturnal systolic blood pressure (BPS) was a risk factor (OR:1.129; p=0.007); 3) five of the normotensive patients (9%) progressed to hypertension; historic HbA1c (OR:2.767; p=0.046) and nocturnal BPD (OR:1.243; p=0.046) being the related risk factors. BPD level ≥65mmHg was associated with an increase in progression of retinopathy and hypertension. CONCLUSIONS In T1DM patients there is an elevated prevalence of BP alterations, detected using ABPM. Alterations in nocturnal BP predispose to development/progression of microvascular complications and overt hypertension.

Characterization of NO-Induced Nitrosative Status in Human Placenta from Pregnant Women with Gestational Diabetes Mellitus

Dysregulation of NO production is implicated in pregnancy-related diseases, including gestational diabetes mellitus (GDM). The role of NO and its placental targets in GDM pregnancies has yet to be determined. S-Nitrosylation is the NO-derived posttranslational protein modification that can modulate biological functions by forming NO-derived complexes with longer half-life, termed S-nitrosothiol (SNO). Our aim was to examine the presence of endogenous S-nitrosylated proteins in cysteine residues in relation to antioxidant defense, apoptosis, and cellular signal transduction in placental tissue from control (n = 8) and GDM (n = 8) pregnancies. S-Nitrosylation was measured using the biotin-switch assay, while the expression and protein activity were assessed by immunoblotting and colorimetric methods, respectively. Results indicated that catalase and peroxiredoxin nitrosylation levels were greater in GDM placentas, and that was accompanied by reduced catalase activity. S-Nitrosylation of ERK1/2 and AKT was increased in GDM placentas, and their activities were inhibited. Activities of caspase-3 and caspase-9 were increased, with the latter also showing diminished nitrosylation levels. These findings suggest that S-nitrosylation is a little-known, but critical, mechanism by which NO directly modulates key placental proteins in women with GDM and, as a consequence, maternal and fetal anomalies during pregnancy can occur.