Expresión disminuida de caspasa 3 asociada al polimorfismo del gen del antígeno-4 asociado a linfocito T-citotóxico (CTLA4) en pacientes chilenos con diabetes tipo 1 / Decreased caspase 3 expression and cytotoxic T lymphocyte antigen-4 polymorphism in Chilean patients with type 1 diabetes

Background: Several polymorphisms of the CTLA4 gene have been associated with autoimmune diseases. The activation of induced cell death is the major event and caspase 3 represents the main protein for the apoptotic machinery, especially in lymphocytes. Aim: To correlate CTLA4 polymorphisms with caspase 3 expression in peripheral blood mononuclear cells (PBMC) simulating in vitro the glucose effect. Material and Methods: CTLA4 polymorphisms were determined by restriction fragment length polymorphisms (RFLPs). PBMC from 21 patients with type 1 diabetes aged 8.5 ± 4.3 years and 21 healthy subjects aged 18.3 ± 1.8 years, were stimulated under normal (5 mM) and toxic (14 mM) glucose conditions to assess its effect on the expression and activity of caspase 3. Relative abundance of caspase 3 mRNA was measured by semi quantitative RT-PCR and its activity, by a colorimetric assay. Results: When stimulated with 14mM glucose, PBMC of G allele carriers with type 1 diabetes had significantly lower relative mRNA abundance of caspase 3 (median value = 0.12, range 0.01-0.70 AU) compared with non-carriers (median value = 0.81, range 0.06-1.09 AU). When the incubation was carried out with the lower glucose concentration, a similar profile of caspase 3 activity was observed in diabetic patients carrying G allele (median value = 0.57, range 0.13-1.20 AU) as compared with non-carriers (median value = 0.89, range 0.14-5.50 AU). No significant changes after stimulating with glucose, were observed in PBMCs of the control group. Conclusions: PBMC of recently diagnosed patients with T1D, carrying the G allele in + 49A/G polymorphisms of CTLA4, have a decreased expression and activity of caspase 3.

Asociación de la variante GHRd3 del receptor de la hormona de crecimiento con autoinmunidad en la diabetes tipo 1 / Association of GHRd3 variant of growth hormone receptor gene with autoimmunity in type 1 diabetes

Background: Growth Hormone Receptor (GRH) is expressed in the liver, pancreas, stomach and small intestine. A high expression of GHR mRNA in the mucosal gut suggests a possible role of this receptor on digestive and immune functions. Aim: To investigate the putative effects of the GHRd3 variants on the cytokine profile and distribution of auto-antibodies in children with type 1 diabetes (T1D). Material and Methods: Unrelated unaffected controls (n =192) and incident cases of children with T1D (n =127) were analyzed for GHRd3 polymorphism, cytokine profile and a panel of auto-antibodies. Results: The allele frequency for d3 was 24.8 percent in type 1 diabetics and 34.1 percent in controls (p =NS). Among type 1 diabetic children, the carriers of the GHRd3 polymorphism had significantly higher levels of interleukin-lB than homozygous for the wild type genotype (5.7 and 17.7, pg/ml respectively p <0.015). Carriers of d3 variant had a higher frequency of positive anti-insulin antibodies (anti-IAA) than children without this variant (39.6 and 17.7 percent respectively, p <0.01). Conclusions: The observed frequency of the GHR d3/d3 genotype was comparable to other reports. A relationship between d3 variant and anti-IAA antibodies and interleukin-1ß was observed.

Polimorfismo +49 A/G del gen del antígeno 4 del linfocito T citotóxico (CTLA-4) en la diabetes tipo 1: Asociación con el perfil de anticuerpos y citoquinas / +49 A/G genetic polymorphism of cytotoxic T lymphocyte associated antigen 4 (CTLA-4) in type 7 diabetes: Association with autoantibodies and cytokines

Background: Cytotoxic T lymphocyte associated antigen 4 (CTLA-4) has been one ofthe non HLA genes more commonly studied in type 1 diabetes mellitus (TID). CTLA-4 is a co-stimulation protein that has a key role in the negative regulation ofT cells and is related with a functional cytokine imbalance, generating a T helper (Th) 1 over Th2 dominance. Aim: To analyze the association of +49 A/G polymorphism of CTLA-4 and its relationship with autoantibodies and cytokine expression in recently diagnosed TID patients. Patients and Methods: CTLA-4 genetic variants and auto-antibody levéis were studied in 260 chiídren with TID and 255 healthy chiídren matched by age and gender +49 A/G polymorphism of CTLA-4 was studied by polymerase chain reaction and restriction fragmentpolymorphism (PCR-RFLP). Autoantibody levéis were measured by conventional ELISA. A panel of60 cytokines was studied simultaneously by serum array analysis in 15 TID and 15 healthy controls stratified according CTLA-4 genotype. Results: The +49 A/G genetic frequency was similar in TID cases and healthy chiídren. A positive anti-GAD65 and anti-IA-2 level was observed in 673 percent of TID group. This percentage was increased among GG carriers (79.4 percent to GAD65 and 70.6 percent to IA-2). Finally, TID patients carrying this genotype showed a high expression of interleukin 2, 10, tumor necrosis factor alpha and interferon gamma. Conclusions: The +49 A/G polymorphism of CTLA-4 was similar in diabetic and control chiídren. Among patients with TID and carriers of GG genotype, a higher frequency of anti-GAD65 and a preferential Thl cytokine expression profile was observed.

Incidencia de diabetes mellitus tipo 1 en Santiago de Chile: análisis por comunas de la Región Metropolitana en el período 2000-2004 / Type 1 diabetes mellitus incidence in Santiago, Chile: Analysis by counties in the period 2000-2004

Background: There are great geographical differences in the incidence of type I diabetes mellitus. Aim: To determine the incidence rate of type 1 diabetes mellitus (DM1) in the Metropolitan Region of Santiago, Chile from January 1, 2000 to December 31, 2004 and to observe the distribution of cases in the different counties of Santiago. Material and methods: All the cases diagnosed with DM1 in the Metropolitan Region who fulfilled the following requirements were included in the study: age of onset <15 years, insulin treatment from onset, permanent residency in the area, and a diagnosis made between January, 2000 and December, 2004. Results: The incidence of DM1 was 6.58/100.000 inhabitants/year, and showed a significant increase from 2001 to 2004 (5.44 and 8.33 inhabitants/year, respectively, p <0.04). The incidence of DM1 also increased significantly in children younger than 4 years old. The incidence by counties exhibited large differences, ranging from 1,5 to 26,6/100.000 inhabitants. Counties with higher income, urbanization and low aborigine component showed a high incidence rate of type 1 diabetes. Conclusions: In the Metropolitan Region of Santiago, an increase of the incidence of DM1 has occurred in the period 2000-2004, especially in children younger than 4 years old. Large differences among counties were observed.

Asociación entre polimorfismos de la región promotora del gen del factor de necrosis tumoral alfa (TNF-alfa) con obesidad y diabetes en mujeres chilenas / Association between tumor necrosis factor-alpha promoter polymorphisms and type 2 diabetes and obesity in Chilean elderly women

Background : Tumor necrosis factor-alpha (TNF-alpha) has an increased expression in the adipose tissue of obese subjects and is involved in insulin resistance. Aim: To screen for associations between -308G/A, -238G/A, -376G/A and -163G/A genetic variants of the TNF-alpha gene, diabetes and obesity-related variables. Material and methods: A group of 263 elderly women aged 60-90 years were recruited. Among them, an oral glucose tolerance test was performed and serum lipids measured in 100 women. TNF-alpha genotypes were determined by polymerase chain reaction (PCR) and analysis of restriction fragment lenght polymorphisms. Results: No significant differences were found when comparing allele frequencies in TNF-alpha polymorphisms of normal subjects with those having impaired glucose tolerance or type 2 diabetes. After excluding patients with previous diagnosis of diabetes, no significant differences by polymorphism carrier status were found for plasma levels of lipids, glucose and insulin. Additionally, no significant differences were found for the association between variables related to adiposity and the ¡308G/A polymorphisms. Conclusions: It is unlikely that polymorphisms in the promoter region of the TNF-alpha gene have a major influence in obesity and diabetes phenotypes in Chilean elderly women.

Prevalencia de diabetes tipo 2 y obesidad en dos poblaciones aborígenes de Chile en ambiente urbano / Prevalence of type 2 diabetes and obesity in two Chilean aboriginal populations living in urban zones

BACKGROUND: The prevalence of cardiovascular risk factors is increasing in aboriginal populations in Chile. AIM: To study the prevalence of obesity, type 2 diabetes and serum lipids in two aboriginal populations, Mapuche and Aymara, that were transferred from a rural to a urban environment. SUBJECTS AND METHODS: Two groups of subjects over 20 years were analyzed, Mapuche and Aymara. The Mapuche group was formed by 42 men and 105 women, living in four urban communities of Santiago, and an Aymara group formed by 42 men and 118 women, living in Arica, in Northern Chile. Anthropometric measurements, blood pressure, lipid profile, oral glucose tolerance test, fasting insulin and serum leptin were determined. RESULTS: The prevalence of type 2 diabetes was 6.9% in Aymara and 8.2% in Mapuche subjects. The frequency of glucose intolerance was similar in both groups, but greater among men. A total blood cholesterol over 200 mg/dl was observed in 43.1% of Aymara and 27.9% of Mapuche subjects (p <0.008). Serum triglycerides over 150 mg/dl were observed in 16.9 and 23.1% of Aymara and Mapuche individuals, respectively (p= NS). CONCLUSIONS: The prevalence of type 2 diabetes and dyslipidemia in turban aboriginal populations is higher than that of their rural counterparts. A possible explanation for these results are changes in lifestyles that come along with urbanization, characterized by a high consumption of saturated fat and refined sugars and a low level of physical activity.

Niveles plasmáticos de citoquinas IL-1ß, IL2 e IL-4 en niños diabéticos tipo 1 de diagnóstico reciente y su asociación con anticuerpos ß pancreáticos / Plasma levels of interleukin-1, interleukin-2 and interleukin-4 in recently diagnosed type 1 diabetic children and their association with ß-pancreatic autoantibodies

Background: Type 1 diabetes is an organ specifc autoimmune disease whose incidence is increasing worldwide. A functional imbalance in cytokine production resulting in dominance of T helper (Th1) over Th2-type response has been suggested to play a critical role in the pathogenesis of type 1 diabetes. Aim: To measure serum concentrations of interleukin (IL)-1ß, IL-2 and IL-4 in children with recently diagnosed type 1 diabetes and to evaluate the autoimmune response measuring glutamic acid decarboxylase (GAD65) and tyrosine phosphatase like (IA-2) autoantibodies. Patients and Methods: 120 diabetic children and 118 age and gender matched control children, were recruited for this study. Circulating levels of IL-1ß, IL-2 and IL-4 were measured by ELISA. GAD65 and IA-2 were measured by RIA. Results: Circulating levels of IL-1ß were elevated in type 1 diabetic children as compared to the control group (9.3±7.3 and 4.9±3.8 pg/ml respectively, p=0,01). Serum concentration of IL-2 was also higher in diabetic patients (19.8±13.1 and 11.3±9.1 pg/ml respectively, p=0,01). No differences in serum IL-4 were observed between diabetics and control. Diabetic children with one or two positive autoantibodies (IA-2 and/or GAD65) had significantly higher levels of IL-1ß and IL-2 and lower levels of IL-4 than diabetic children without positive autoantibodies. High concentrations of IL-1ß were associated with an early onset of the disease. Conclusions: High levels of IL-1ß and IL-2 were found in diabetic children with recent diagnosis of the disease. Diabetics with positive antibodies against GAD65 and IA-2 had higher levels of IL-1ß and IL-2 and lower levels of IL-4 than their counterparts without positive antibodies.

Prevalencia familiar de patologías metabólicas en paciente con síndrome de ovario poliquístico / Prevalence of metabolic disorders among family members of patients with polycystic ovary syndrome

Background: About 60 percent of patients with polycystic ovary syndrome (PCOS) have insulin resistance, predisposing them to the premature coronary disease and type 2 -diabetes mellitus. However, the history of metabolic disorders in family members of patients with PCOS has been seldom documented in the literature. Aim: To evaluate the family profile of metabolic disorders of PCOS patients and to determine their relative risk of developing one of them in comparison to a control group. Patients and Methods: Sixty PCOS patients were evaluated. The control group were 60 normal women. The data were obtained from the clinical history and personal interview with the patients, the controls and their relatives (brothers, parents and grandparents). The metabolic disorders considered were: dyslipidemia, obesity, hypertension and diabetes. Results: The ages were similar between groups (PCOS: 24.0 ñ 6.3; control group: 24.8 ñ 6.2 years). The prevalence of metabolic disorders was 62 percent in the relatives of the PCOS patients and 27.8 percent in the relatives of the control group (p <0.005). The probability to develop a metabolic disorder within the family was 2.7 (2.2-3.3) fold higher in the PCOS group compared to the control group. The risk of developing hypertension, dyslipidemia, obesity and diabetes was 2.1 (1.5-2.9); 1.8 (1.5-2.7); 3.6 (2.6-4.9) and 2.7 (1.8-3.9), respectively, in the PCOS group compared to the control group. Conclusions: The probability of finding a metabolic disorder in the families of PCOS patients, is 2.7 fold higher than in the control group families. The metabolic disorders are more frequent in parents and grandparents of the PCOS patients than in those of normal women

Síndrome de ovario poliquístico: la importancia de establecer su diagnóstico / Polycystic ovary syndrome: the importance of establishing diagnosis

Polycystic ovary syndrome (PCOS) is a very common disorder that occurs up to 10 percent of premenopausal women. Although PCOS is known to be associated with a higher reproductive morbility and increased risk of hormone dependent-cancer, its diagnosis is particularly important because PCOS is strongly linked to insulin resistance. This involves a major risk of early metabolic and cardiovascular complications. On the other hand, the prevalence of metabolic disorders associated with insulin resistance is higher in family members of patients with PCOS than in those of normal women, which suggests that the treatment of this syndrome should be preventive rather than symptomatic. For that reason, PCOS might be considered a signal of a family disorder, a route to diabetes and a public health problem