ABSTRACT
Existe un creciente reconocimiento del importante papel de la insulinorresistencia (IR) en la patogénesis de la diabetes tipo 2 en niños y adolescentes. Nos propusimos obtener los percentilos de referencia y la prevalencia de insulinemia en ayunas e índices de IR, HOMA y QUICKI en adolescentes escolarizados de la ciudad de Posadas-Misiones. Se realizó un estudio descriptivo transversal en 420 estudiantes de nivel secundario. Se evaluaron parámetros antropométricos, circunferencia de cintura y presión arterial. Se realizó una extracción sanguínea con 12 horas de ayuno para las determinaciones bioquímicas: glucemia, perfil lipídico e insulina. Las muestras fueron procesadas con control de calidad interno y externo. Se encontró que el percentilo 95 de Insulina fue ≥ 12 mU/lt y de HOMA ≥ 2,5 y percentilo 5 para QUICKI ≤ 0.33. De la comparación entre sexos, no se halló diferencias significativas en los valores de los índices HOMA y QUICKI (U = 3077, p = 0,058), pero con Insulina se observaron diferencias significativas, mujeres = 8,59 ± 2,93 mU/l vs. varones = 6,50 ± 2,55 mU/l (U = 2929; p = 0,019). Sin embargo, al aplicar la prueba z y el 1,5 del DE, no sería necesario el cálculo para grupos separados por sexo (z calculado = 2,63; z crítico = 2,47; 1,5 DE = 3,82 mU/l). 11,7 % presentó Hiperinsulinemia y la prevalencia de IR según HOMA fue 10,5 % y 9,8 %, por QUICKI, sin diferencias estadísticas según sexo y grupo de edad. Insulinemia y ambos índices de IR estaban significativamente más elevados en los adolescentes con sobrepeso u obesos. Estos valores podrán ser utilizados como guía en el algoritmo diagnóstico de IR por parte de la comunidad médica.
Introduction: There is a growing recognition of the important role of insulin resistance (IR) in the pathogenesis of type 2 diabetes in children and adolescents. The aim of this study was to obtain the reference percentiles and the prevalence of fasting insulin and index of IR, HOMA and QUICKI, in adolescents in the city of Posadas, Misiones. Materials and Methods: A descriptive study of 420 high-school students was performed. Anthropometric parameters, waist circumference and blood pressure were evaluated. Blood samples were taken after 12 hours fasting for biochemical measurements: fasting glucose, lipid profile and insulin. The samples were processed in-house and external quality control. Results: Percentile 95 of Insulin ≥ 12 mU/lt, HOMA ≥ 2.5 and percentile 5 for QUICKI was ≤ 0.33. Comparison between genders showed no significant differences in HOMA and QUICKI values (U = 3077, p = 0.058), but significant differences were found for insulin: females = 8.59 ± 2.93 mU/l, males = 6.50 ± 2.55 mU/l (U = 2929, P = 0.019), However, when applying the z test and 1.5 of SD, calculation for groups separated by gender would not be necessary (calculated z = 2.63, critical z = 2.47, 1.5 SD = 3.82 mU/l). 11.7 % were hyperinsulinemic and the prevalence of IR by HOMA was 10.5 % and 9.8 % for QUICKI, with no statistical differences by sex and age group. Insulin and two indexes of IR were significantly higher in overweight or obese adolescents. Conclusions: These values may be used as a guide in the diagnostic algorithm of IR by the medical community.
ABSTRACT
La resistencia insulínica es una disminución de la función biológica de la insulina caracterizada por requerir un alto nivel de insulina plasmática para mantener la homeostasis metabólica. Su presencia está asociada con mayor riesgo de enfermedad cardiovascular. Nos propusimos conocer la frecuencia de hiperinsulinemia e insulinorresistencia en empleados del hospital Dr. Ramón Madariaga, correlacionar la insulinorresistencia a través del índice HOMA con edad, presión arterial, obesidad y obesidad abdominal y evaluar su relación con sexo, presión arterial, obesidad y obesidad abdominal. Se estudiaron 170 sujetos de ambos sexos que tenían entre 27 y 74 años de edad, de los cuales 134 fueron de sexo femenino y 36 de sexo masculino. Se obtuvieron datos antropométricos y presión arterial. Se realizó una extracción sanguínea con un ayuno de 12 horas para las determinaciones bioquímicas. Todos los análisis estadísticos se realizaron utilizando el programa Epi-info 2000, con un nivel de confianza del 95 % y un nivel de significación <0.05. Las frecuencias de in-sulinorresistencia e hiperinsulinemia que se obtuvieron fueron de 7.1 % y 8.2 % respectivamente. El índice HOMA mostró una correlación altamente significativa (p<0.001) para circunferencia de cintura (obesidad abdominal), índice de masa corporal y presión arterial. Cuando evaluamos el comportamiento del índice HOMA entre las diferentes categorías de presión arterial, IMC y circunferencia de cintura, encontramos diferencia significativa (p<0.001), para todos ellos. La valoración de la insulinorresistencia demostró la clara relación existente entre obesidad, obesidad abdominal e hipertensión. Esto permitirá identificar a los individuos con mayor riesgo para las enfermedades cardiovasculares y así poder implementar medidas terapéuticas (dieta, actividad física y/o farmacológicas) para poder retrasarlas o impedirlas, dando a nuestros pacientes una mejor calidad de vida. Los autores declaran no poseer conflictos de interés.
According to 2008 data from the Ministry of Public Health of the Province of Misiones, cardiovascular disease is the main cause of mortality in that province, with a proportional mortality ratio of 28.3 %, and with a process known as arteriosclerosis as the main responsible factor. Arteriosclerosis is a chronic inflammatory process where endothelial dysfunction plays a major role. Insulin resistance (IR), described as a condition in which there is a decrease in the biological function of insulin and high plasma levels of insulin are required to maintain metabolic homeostasis, promotes atherosclerotic development and its presence is associated with an increased risk of cardiovascular disease. Our aim was to determine the frequency of hyperinsulinemia and IR in a group of employees at the Public Provincial Hospital Dr. Ramón Madariaga, to correlate IR with age, blood pressure, general and abdominal obesity and to evalúate our subjects' performance using the HOMA Índex. One-hundred and seventy subjects of both genders (134 females and 36 males) with an age range between 27 and 74 years oíd were studied. Participation in the trial was voluntary and written consent was obtained using an authorization model based on the Declaration of Helsinki. Weight, height and waist circumference data were recorded under WHO standards. Subjects were classified as normal, overweight and obese depending on their Body Mass índex. Blood pressure was measured with a mercury sphygmomanometer and following the American Heart Association recommendations. Blood samples were collected after 8 hours of fasting and glucose was measured by enzymatic colorimetric methods (CV = 2.38 %). Insulin was measured by radioimmunoanalysis (CV=8 %). The Internal Quality Control was performed with a serum pool prepared in the laboratory, and the External Quality Control was carried out with controls provided by the Argentine Biochemical Foundation. All the statistical analyses were performed using the Epiinfo 2000 program, with a confidence interval of 95 % and a significance level <0.05. The frequencies of IR and hyperinsulinemia obtained were 7.1 % and 8.2 %, respectively The HOMA Índex showed a highly significant correlation (p<0.001) for waist circumference (abdominal obesity), body mass Índex (obesity) and blood pressure. When assessing the HOMA Índex performance, it was found that individuáis with abdominal obesity had a higher IR (p<0.001). In addition, the IR Índex mean valué increased with body mass Índex (p<0.001). Subjects with prehypertension and hypertension showed higher HOMA valúes as compared to subjects with normal blood pressure (p<0.001), when the evaluation was performed according to the different blood pressure categories. The assessment of insulin resistance showed a clear relationship between obesity, abdominal obesity and hypertension. This assessment will make it possible to identify individuáis at increased risk for cardiovascular disease so as to implement treatment measures (diet, physical activity and / or pharmacological treatment) to delay or prevent the occurrence of disease, offering our patients an improved quality of life. No competing financial interests exist.