Valores de referencia de las hormonas tiroideas y TSH en individuos adultos de Maracaibo, Venezuela

Introducción: A nivel mundial, nacional o regional no existe un consenso ampliamente aceptado para los valores de referencia de hormonas tiroideas. Por ello, el objetivo de este estudio fue determinar los valores de referencia de TSH, FT3 libre y FT4 libre en individuos adultos del Municipio Maracaibo, Estado Zulia. Materiales y Métodos: Se realizó historia clínica completa y se determinó la concentración plasmática de TSH, T3L, T4L y anticuerpos anti-tiroideos a 425 individuos seleccionados al azar del Estudio de Prevalencia de Síndrome Metabólico en la ciudad de Maracaibo, un estudio descriptivo, transversal, con muestreo aleatorio multietápico que cuenta con una muestra de 2.230 individuos mayores de 18 años de ambos sexos. Para obtener la población de referencia (n=266) y establecer los intervalos de referencia se excluyeron individuos con antecedentes personales y familiares de enfermedad tiroidea, anticuerpos antitiroideos positivos (anti-tiroglobulina y anti-peroxidasa tiroidea), antecedentes personales de enfermedades cardiovasculares o autoinmunes, diabetes mellitus y uso de medicamentos tales como betabloqueantes, esteroides, anticonceptivos orales, amiodarona y levotiroxina. Resultados: Los valores de referencia de TSH, T3L y T4L  fueron establecidos mediante los percentiles 2,5 y 97,5 para establecer el límite inferior y superior en la población de referencia. De esta manera se obtuvieron los siguientes resultados TSH 0,70-5,52 mUI/L, T3L 1,80-4,40 pg/mL, T4L 0,80-1,80 ng/dL. Conclusiones: Los valores de referencia obtenidos en nuestra población difieren a los reportados en otros países, siendo necesario determinar valores de referencia en cada población con la finalidad de diagnosticar de forma adecuada las patologías relacionadas con hipo e hiperfunción tiroidea.Introduction: Currently there is no consensus regarding reference values for thyroid hormone profile. The purpose of this study was to determine the references values of TSH, Free T3 and Free T4 in adults from the Maracaibo Municipality, Zulia State. Materials and Methods: the Maracaibo city Metabolic Syndrome Prevalence Study is a cross-sectional study which enrolled 2.230 individuals of both sexes over 18 years of age, out of which 425 were selected due to medical history and availability of thyroid function quantification. The reference population subsample was obtained (n=266) by excluding those with personal and family history of thyroid disease, positive anti-thyroid antibodies, cardiovascular or autoimmune diseases, diabetes mellitus and medication usage. Results: the references values for TSH, FT3 and FT4 are between 2.5th and 97.5th to establish an upper and lower limit respectively: TSH 0.70-5.52 mIU/L, FT3 1.80-4.40 pg/ mL, FT4 0.80-1.80 ng/dL. Conclusions: the reference values obtained for our population differ from previous reports from other countries, strengthening the notion that each populace needs their own threshold values, facilitating a proper and efficient diagnosis tool to detect thyroid abnormalities&nbsp

Comportamiento epidemiológico del hipotiroidismo subclínico y su asociación con factores de riesgo cardiometabólicos en individuos adultos del Municipio Maracaibo, Venezuela

Introducción: La relación entre el hipotiroidismo subclínico (HSC) y diversos factores de riesgo cardiovascular es controversial. El objetivo de este estudio es analizar el comportamiento de dichos factores en adultos con HSC del municipio Maracaibo, estado Zulia, Venezuela. Materiales y Métodos: Se seleccionaron 425 individuos de la base de datos del estudio de Prevalencia de Síndrome Metabólico de Maracaibo, en base a historia clínica y determinación de TSH, T3, T4, anticuerpos anti-tiroideos, glicemia, insulina basal y perfil lipídico. Las variables cualitativas fueron expresadas como frecuencias absolutas y relativas y las variables cuantitativas como media aritmética ± DE, se realizó un modelo de regresión logística múltiple para determinar la relación entre los factores de riesgo con respecto al diagnóstico de HSC. Resultados: La prevalencia del HSC fue 9,6% (n=41), presentando elevación de la glicemia, colesterol total, triacilglicéridos y VLDL, y disminución de T3 (p=0,017). La presencia de HSC es directamente proporcional a la edad y presenta una asociación significativa con anticuerpos anti-tiroideos positivos. El HSC mostró incrementar el riesgo para enfermedades cardio-metabólicas como Diabetes Mellitus tipo 2 y enfermedad cardiovascular. Conclusiones: La prevalencia de HSC es similar a la mostrada en reportes previos, estando asociado con la presencia de varios factores cardio-metabólicos. Es necesaria la determinación oportuna del perfil tiroideo, especialmente adultos mayores, para un diagnóstico precoz y adecuado seguimiento de este grupo de pacientes.&nbsp

Biologic Behavior and optimal cut-off point estimation for Serum Fasting Insulin: A report from the Maracaibo City Metabolic Syndrome Prevalence Study

Introduction: Insulin resistance is a metabolic state in which tissue effects of insulin are diminished, leading to hyperinsulinemia as a compensatory mechanism. The combination of insulin resistance and hyperinsulinemia constitutes one of the main pathophysiological landmarks of Metabolic Syndrome. Thus, our main objective was to determine a cut-off point for serum fasting insulin in the population of Maracaibo. Materials and Methods: Descriptive, cross-sectional study realized in 2,026 subjects of both genders, 18 years of age or older, who had their serum fasting insulin quantified. These values underwent logarithmic transformation for normalization of their distribution, which was corroborated through Geary’s test. Results were expressed as means ± SD. A cut-off was selected through the construction of ROC Curves using selected healthy and “sick” populations. Results: In the studied population (n=2,026) the mean serum fasting insulin concentration was 14.6±9.5 μU/mL. When stratifying by gender, a mean of 14.5±9.3 μU/ mL was observed in women and 14.8±9.8μU/mL in men; p=0.715. When assessing these levels by age groups, BMI and waist circumference, a progressive increase was observed along each category. The selected cut-off point for serum fasting insulin concentration was 13μU/mL; AUC=0.792; Sen=74.4%; Esp=71.3%. Conclusions: Serum fasting insulin concentrations increase with age, BMI and waist circumference. A cut-off point of 13μU/mL is suggested for the definition of fasting hyperinsulinemia in our population

Prevalence, awareness, management of hypertension and association with metabolic abnormalities: the Maracaibo city metabolic syndrome prevalence study

Background: The purpose of this study was to determine the prevalence and epidemiologic behavior of Hypertension (HT) in the Maracaibo Municipality, Zulia state, Venezuela. Materials and Methods: This was a cross-sectional descriptive study, where 2,230 subjects from both genders were randomly selected as part of the Maracaibo city Metabolic Syndrome Prevalence Study (MMSPS). Complete medical examination, laboratory workup and anthropometry measurements were taken. The quantitative variables were expressed as mean±SD, and comparisons were calculated using t Student test. The qualitative variables were represented as absolute and relative frequencies, and comparisons were obtained using Z test for proportions and associations with c2 test. Results: The prevalence of HT was 19.42% (20.92% in women and 17.75% in men). The prevalence of newly diagnosed individuals was 12.0%, with 8.71% in women and 16.90% in men. The overall percentage of HT was 32.02%, being 29.63% in women and 34.65% in men. Several variables were associated with HT, such as glycemic status (χ2=64.97, p<0.001), insulin resistance (c2=25.58, p<0.001) and body mass index (c2=209.952, p<0.0001). Clinical control of blood pressure was observed in 44.7% of treated and 56.6% of untreated subjects. The most frequent anti-hypertensive drugs were: Angiotensin Converting Enzyme Inhibitors with (n=105), Beta-Blockers (n=97) and Angiotensin Receptor II Blockers (n=32). Conclusion: Even though elevated numbers of AHT are observed in our population combined with low clinical control of blood pressure, there is a lower prevalence of AHT compared to other studies at regional, national or international levels.&nbsp