El adelanto en la telarquia y edad de la menarquia se relacióna con la malnutrición por exceso en niñas chilenas pero no en varones: estudio de base poblacional / The advance in thelarche and age of menarche is related to malnutrition by excess in Chilean girls but not in boys: population-based study

Introduction: Puberty normally begins after 8 years in girls and 9 years in boys. Objective: To determine the prevalence of signs of precocious puberty (PP), breast development in girls, premature gonadal development (PGD), premature adrenarche (PA), menarche age (MA) and its association with nutritional status (NS). Material and Methods: From a sample of 3.010 children from 5 to 14 years randomly selected in Santiago of Chile were chosen a subsample of 873 kids according to the cutoff to define PP. Survey was applied to obtain MA. Logistic regression were used to evaluate the relationship between PP and NS. Results: In boys the prevalence of PGD and PP was 8.55% and 3.16% respectively, no relationship was found with nutritional status In girls the prevalence of breast development and PA was 8.13% and 0.9% respectively. Only there be association between PP and NS in women: with a prevalence of 1,2%, 13,9% and 21,1% in well-nourished, Overweight and obesity are at greater risk of showing PP compared with eutrophic girls with an OR of 25,5 (IC 95% 3,2-203,0) and 46.93 (IC 95% 6,1-361,5). MA was 12,01 ± 0,94 years in eutrophic girls and 11,40 ± 0,96years in obese girls (p< 0,05). Conclusion: There was a positive correlation in females between overweight and obesity an PP and MA. There is a secular trend in MA, to compare these findings with other national studies. Obesity could have an important role in explaining the advancement observed in pubertal development.

Introducción: El desarrollo puberal se inicia normalmente después de los 8 años en niñas y de los 9 años en varones. Objetivo: Estimar la prevalencia de signos de pubertad precoz (sPP): crecimiento genital (CG) en varones, telarquia en niñas y vello púbico (VP) en ambos sexos; y determinar edad de la menarquia (EM) en una muestra de escolares de Santiago de Chile), y evaluar la asociación de estas variables con el estado nutricional (EN). Material y Métodos: Se examinaron 3.010 escolares de clase media baja de 6 a 14 años, pertenecientes a 10 colegios de Santiago de Chile y seleccionados aleatoriamente. En todos ellos se consignó peso, talla, IMC y desarrollo puberal según Tanner. Se aplicó una encuesta a los padres para obtener la EM a la población total de mujeres (n= 1.433). Para determinar sPP se analizaron por separado los 867 niños (62% mujeres) menores a la edad establecida como puntos de corte para definir PP. Se utilizó regresión logística para determinar la asociación existente entre sPP y el EN. Resultados: En varones la prevalencia de CG y VP fue de 8,55% y 3,16% y no se asocio al EN. La prevalencia de telarquia y VP en niñas fue de 8,13% y 0,9% respectivamente. Se observó una fuerte asociación entre telarquia y EN con prevalencias de 1.2%, 13.9% y 21.1% en eutróficas, sobrepeso y obesas, respectivamente (p< 0,0001) (Gráfico 1). La presencia de sobrepeso y/o obesidad otorgan un mayor riesgo de presentar telarquia, vs comparación con las niñas eutróficas con un OR de 25,5 (IC 95% 3,2-203,0) y 46.93 (IC 95% 6,1-361,5), respectivamente. La EM fue 12,01 ± 0,94 años en niñas eutróficas siendo de 11,40 ± 0,96 años en niñas obesas (p< 0,05). Conclusión: Se observó una correlación positiva solo en el sexo femenino entre malnutrición por exceso, telarquia precoz y EM. Se observa una tendencia secular en la EM al comparar los hallazgos con otros estudios nacionales.

La autoevaluación es un método poco confiable para establecer el desarrollo puberal en escolares / Self evaluation is not reliable for assessing puberal development in school-aged children

Introduction: Puberal development assessment (PDA) is performed according Tanner's method (TM). Objective: In order establish the coincidence between PDA determined by physicians and the self-evaluation by school-aged children. Material and Methods: 2 980 school children from Santiago, Chile, were assessed by means of TM, the development of the mammary gland (MD), male genitalia (MG) and pubic hair (PH) were assessed. PDA was simultaneously performed by physicians and by the school children. Results: Concordance between physicians and self assessment showed a kappa coefficient (KC) of 0.55, 0.45, and 0.51 in PH, MD and MG respectively, (acceptable KC > 0.61). Self-evaluation of PDA decreased as the age of children increased, with OR of 0.76 (95 percent IC 0.74 -0.79); 0.87 (95 percent IC 0.83 - 0.91) and 0.92 (95 percent IC 0.88 - 0.96) for PH, MD and MG respectively. An inverse relationship between nutritional status (NS) and PDA was observed only in PH, obese school children underscored their PH (OR 0.6; 95 percent IC 0.5 - 0.7). Multivariate analysis for gender and NS showed that only females overestimate their PH, OR of 1.15 (95 percent IC 1-1.32). Conclusions: PDA through self-assessment yields only moderate correlation coefficients, thus it is not reliable for making relevant clinical decisions.

Introducción: La determinación del desarrollo puberal (DDP) se evalúa según el método de Tanner (MT). Objetivo: Determinar la concordancia de la DDP entre médicos con la autoevaluación en escolares. Pacientes y Métodos: Se examinaron 2 980 escolares de Santiago de Chile. Se evalúo desarrollo mamario (DM), genitales masculinos (GM) y vello púbico (VP) mediante el MT. La DDP fue evaluada simultáneamente por un médico y por los escolares. Resultados: La concordancia entre médicos y la autoevaluación mostró un coeficiente kappa (CK) de 0,55, 0,45, 0,51 en VP, DM y GM respectivamente, (CK aceptable > 0,61). La autoevaluación del DDP disminuyo a medida que aumentaba la edad, con OR respectivos de 0,76 (95 por ciento IC 0,74-0,79); 0,87 (95 por ciento IC 0,83-0,91) y 0,92 (95 por ciento IC 0,88 -0,96) para VP, DM y GM. Se observo una relación inversa entre estado nutricional (EN) y DDP sólo en VP, escolares obesos subestimaban su VP (OR 0,6; 95 por ciento IC 0,5-0,7). El análisis multivariado de género y EN mostró que sólo las mujeres sobreestimaban su VP, OR de 1,15 (95 por ciento IC 1-1,32). Conclusiones: La DDP mediante autoevaluación obtiene coeficientes de correlación sólo moderados que no permiten confiar en este para establecer decisiones clínicas relevantes.

Síndrome hemolítico urémico en Chile: presentación clínica, evolución y factores pronósticos / Hemolytic-uremic syndrome in Chile: clinical features, evolution and prognostic factors

Background: Hemolytic-uremic syndrome (HUS) is characterized by acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia. Aim: To describe the characteñstics ofpatients with the diagnosis ofHUS in Chile, and to identify the most reliable early predictors oímorbidity and moñality. Material and methods: The clinical records ofpatients with HUS aged less than 15 years, attended between January 1990 and December 2003 in 15 hospitals, were reviewed. Demographic, clinical, biochemical, hematological parameters, morbidity and mortality were analyzed. Results: A cohort of 587 patients aged 2 to 8 years, 48 percent males, was analyzed. Ninety two percent had diarrhea. At the moment of diagnosis, anuria was observed in 39 percent of the patients, hypertension in 45 percent and seizures in 17 percent. Forty two percent required renal replacement therapy (RRT) and perítoneal dialysis was used in the majoríty of cases (78 percent). The most frequently isolated etiological agentwas Escherichia coli. Mortality rate was 2.9 percent in the acute phase of the disease and there was a positive correlation between mortality and anuria, seizures, white blood cell count (WCC) >20.000/mm³ and requirements of renal replacement therapy (p <0.05). Twelve percent of patients evolved to chronic renal failure and the risk factors during the acute phase were the need for renal replacement therapy, anuria, WCC >20.000/mm³, seizures and hypertension. Conclusions: The present study emphasizes important clinical and epidemiological aspeets ofHUSin a Chilean pediatricpopulation.

[Hemolytic-uremic syndrome in Chile: clinical features, evolution and prognostic factors]. / Síndrome hemolítico urémico en Chile: presentación clínica, evolución y factores pronósticos.

BACKGROUND: Hemolytic-uremic syndrome (HUS) is characterized by acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia. AIM: To describe the characteristics of patients with the diagnosis of HUS in Chile, and to identify the most reliable early predictors of morbidity and mortality. MATERIAL AND METHODS: The clinical records of patients with HUS aged less than 15 years, attended between January 1990 and December 2003 in 15 hospitals, were reviewed. Demographic, clinical, biochemical, hematological parameters, morbidity and mortality were analyzed. RESULTS: A cohort of 587 patients aged 2 to 8 years, 48% males, was analyzed. Ninety two percent had diarrhea. At the moment of diagnosis, anuria was observed in 39% of the patients, hypertension in 45% and seizures in 17%. Forty two percent required renal replacement therapy (RRT) and peritoneal dialysis was used in the majority of cases (78%). The most frequently isolated etiological agent was Escherichia coli. Mortality rate was 2.9% in the acute phase of the disease and there was a positive correlation between mortality and anuria, seizures, white blood cell count (WCC)>20.000/mm3 and requirements of renal replacement therapy (p<0.05). Twelve percent of patients evolved to chronic renal failure and the risk factors during the acute phase were the need for renal replacement therapy, anuria, WCC>20.000/mm3, seizures and hypertension. CONCLUSIONS: The present study emphasizes important clinical and epidemiological aspects of HUS in a Chilean pediatric population.