Marcadores inmunológicos de diabetes tipo 1: análisis de 4.164 perfiles en un centro de salud de Chile / Analysis of 4, 164 type 1 diabetes antibody profiles in a Chilean health centre

Background: Previous studies have assessed the role of Type 1 diabetes (DM1) antibodies as predictors of the natural history of disease. Aim: To determine the frequency and combinations of positivity for DM1 antibodies in patients with DM1 and the relationship between antibody positivity and the age of the patient. To explore the relationship between history of insulin therapy or diabetic ketoacidosis (DKA) at the onset of the disease with antibody positivity in a subsample. Material and Methods: Data was gathered from every sample processed for DM1 antibodies in our laboratory between January 2015 and September 2019. Medical records from 84 patients who tested positive for at least one antibody were revised to study the relationship between insulin therapy or DKA at the onset of the disease with antibody positivity. Results: Forty percent of DM1 antibody tests were positive. Among positive tests, 1, 2, 3 or 4 DM1 antibodies were detected in 48%, 33%, 17% and 3% of cases, respectively. The likelihood of testing positive was inversely related with age for ICA, GAD, IA-2, ZnT8 and directlyproportionalforIAA (p= −0,012; −0,013; −0,014; −0,009; 0,005 respectively). An association between DKA at the onset of the disease and IA-2 positivity was observed (Odds ratio (OR) 5.38 95% confidence intervals (CI) 1.79 − 16.16, P < 0.01). No association was found between IAA positivity and history of insulin therapy (OR 2.25 95%CI 0.63 − 7.90, P = 0.2403). The results obtained from this study represent a novel local profile of DM1 antibody data, highlighting a relationship between antibody positivity and age.

II Consenso de la Sociedad Chilena de Endocrinología y Diabetes sobre resistencia a la insulina

Insulin resistance is a prevalent condition commonly associated with unhealthy lifestyles. It affects several metabolic pathways, increasing risk of abnormalities at different organ levels. Thus, diverse medical specialties should be involved in its diagnosis and treatment. With the purpose of unifying criteria about this condition, a scientific-based consensus was elaborated. A questionnaire including the most important topics such as cardio-metabolic risk, non-alcoholic fatty liver disease and polycystic ovary syndrome, was designed and sent to national experts. When no agreement among them was achieved, the Delphi methodology was applied. The main conclusions reached are that clinical findings are critical for the diagnosis of insulin resistance, not being necessary blood testing. Acquisition of a healthy lifestyle is the most important therapeutic tool. Insulin-sensitizing drugs should be prescribed to individuals at high risk of disease according to clinically validated outcomes. There are specific recommendations for pregnant women, children, adolescents and older people.

Evaluación de la insulinemia post carga oral de glucosa como método diagnóstico de resistencia a la insulina / Evaluation of serum insulin levels after an oral glucose load for the diagnosis of insulin resistance

Background: In our country, the assessment of insulin resistance (IR) measuring serum insulin levels at 60 and 120 minutes after a 75 g oral glucose tolerance test (OGTT), is usual. However, there is no information about the distribution of serum insulin levels in the Chilean population. Aim: To assess the distribution of serum insulin levels at 60 and 120 minutes during OGTTs and suggest a statistical cut-off point to estimate the degree of IR. Material and Methods: Retrospective analysis of 1815 OGTTs performed in non-diabetic subjects aged between 18 and 75 years, at a university medical center. HOMA-IR (Homeostasis Model Assessment), insulin sensitivity index of Matsuda (ISI-Composite), and their correlation with serum insulin levels at 60 and 120 minutes were calculated. Results: The 75th percentiles for serum insulin levels at 60 and 120 minutes were 127 and 81 µU/mL, respectively. There was a high correlation between HOMA-IR and ISI-Composite (r = -089, p < 0.001). There was a weaker although significant correlation between HOMA-IR and ISI-Composite and insulin levels at 60 (r = 0.56 and -0.79 respectively, p < 0,001) and 120 minutes (r = 0.54 and -0.75 respectively, p < 0,001). Conclusions: We propose 60 and 120 min serum insulin levels of 130 and 80 µU/mL respectively, as cut-off values for normality during OGTT in Chilean normoglycemic individuals.

Características clínicas y metabólicas de los estados de intolerancia a la glucosa y glicemia de ayuno alteradas / Clinical and metabolic features of subjects with glucose intolerance and high fasting glucose levels

Background: Subjects with glucose intolerance or high fasting glucose levels have a higher cardiovascular risk and frequently become diabetic. Aim: Toassess clinical and metabolic characteristics of patients with glucose intolerance or high fasting glucose levels. Material and methods: Fasting and post glucose load serum glucoseand insulin levels were measured in 1404 people, aged 42,0 ± 14,2 years (81% women) with high diabetic risk. We categorized subjects in different alterations of blood glucose, accordingto 2006 American Diabetes Association categories. Insulin resistance (RI), insulin secretion (ß %) and insulin disposition (ID), were calculated using fasting blood glucose and insulin levels, using the homeostasis model assessment (HOMA I and II). Results: Sixty percent of studied subjects had first grade relatives with diabetes mellitus and 1097 (78%) were categorized as normal (N), 45 (3%) as Diabetes Mellitus (DM), 161 (11%) as high fasting glucose levels (GAA) and 103 (7%) as glucose intolerant (ITG). Fifty three of the 106 subjects with GAA (50%), were also glucose intolerant. Subjects with GAA had similar insulinsensitivity and lower ß cell function than N (insulin disposition 58 ± 12 and 111 ± 32%, respectively, p <0.01). ITG had less insulin sensitivity than N (HOMA-IR 2.6 ± 1.50 ± and 2.0 ± 1.30, respectively) and only a mild decrease in ß cell function (insulin disposition 96 ± 26 and 111 ± 32% respectively, p < 0.01). Patients GAA plus ITG had similar alterations than those with DM (HOMA-IR 3.8 ± 2.2 and 4.4 ± 3.7 respectively; insulin disposition 57 ± 10 and 56.0 ± 26% respectively. Conclusions: Patients with higher fasting glucose levels behavedifferently from those with glucose intolerance. High fasting glucose levels are highly prevalent in subjects with high risk of DM and must be considered as risk indicator in preventive programs for diabetes mellitus.