Abstract: Objective: To describe the characteristics of Mexican children and adolescents 5-17 years with severe functioning difficulties and disability and explore their participation in child labor. Materials and methods: Using data from the National Survey of Boys, Girls and Women in Mexico 2015 we estimated prevalence of functioning difficulties and disability and used logistic regression to explore the association between this condition and child labor. Results: While 11.2% of Mexicans 5-17 years-old has severe functioning difficulties or disability, 13.4% work. The functioning difficulty and disability domains with the highest prevalence are experiencing anxiety (5.4%) and depression (1.5%) daily. Children and adolescents with severe functioning difficulties and disability are 70% more likely to do child labor [OR=1.7, 95%CI:1.2,2.4]. Educational lag doubles the likelihood of doing child labor [OR=2.2, 95%CI:1.5,3.3]. Conclusions: Guaranteeing educational opportunities and respect for the rights of children with severe functioning difficulties and disability is essential to achieve development of their full potential.

Resumen: Objetivo: Describir la población mexicana de 5-17 años con problemas severos de funcionamiento y discapacidad y explorar su realización de trabajo infantil. Material y métodos: Basado en la Encuesta Nacional de Niños, Niñas y Mujeres 2015, se estimaron prevalencias de problemas de funcionamiento y discapacidad y se exploró la relación con el trabajo infantil en un modelo de regresión logística. Resultados: El 11.2% de los mexicanos de 5-17 años tiene dificultades severas de funcionamiento o discapacidad y 13.4% realiza trabajo infantil. Los ámbitos con la mayor prevalencia fueron ansiedad (5.4%) y depresión (1.5%) experimentadas diariamente. Niños y adolescentes con problemas severos de funcionamiento o discapacidad tienen 70% más posibilidades de realizar trabajo infantil [RM=1.7, IC95%:1.2,2.4]. El rezago educativo duplica las posibilidades de realizar trabajo infantil [RM=2.2, IC95%:1.5,3.3]. Conclusiones: Es imprescindible garantizar oportunidades educativas y respeto a los derechos de la población infantil con problemas de funcionamiento y discapacidad para lograr su desarrollo integral.

Abstract: Objective: To describe the characteristics of Mexican children and adolescents 5-17 years with severe functioning difficulties and disability and explore their participation in child labor. Materials and methods: Using data from the National Survey of Boys, Girls and Women in Mexico 2015 we estimated prevalence of functioning difficulties and disability and used logistic regression to explore the association between this condition and child labor. Results: While 11.2% of Mexicans 5-17 years-old has severe functioning difficulties or disability, 13.4% work. The functioning difficulty and disability domains with the highest prevalence are experiencing anxiety (5.4%) and depression (1.5%) daily. Children and adolescents with severe functioning difficulties and disability are 70% more likely to do child labor [OR=1.7, 95%CI:1.2,2.4]. Educational lag doubles the likelihood of doing child labor [OR=2.2, 95%CI:1.5,3.3]. Conclusions: Guaranteeing educational opportunities and respect for the rights of children with severe functioning difficulties and disability is essential to achieve development of their full potential.

Resumen: Objetivo: Describir la población mexicana de 5-17 años con problemas severos de funcionamiento y discapacidad y explorar su realización de trabajo infantil. Material y métodos: Basado en la Encuesta Nacional de Niños, Niñas y Mujeres 2015, se estimaron prevalencias de problemas de funcionamiento y discapacidad y se exploró la relación con el trabajo infantil en un modelo de regresión logística. Resultados: El 11.2% de los mexicanos de 5-17 años tiene dificultades severas de funcionamiento o discapacidad y 13.4% realiza trabajo infantil. Los ámbitos con la mayor prevalencia fueron ansiedad (5.4%) y depresión (1.5%) experimentadas diariamente. Niños y adolescentes con problemas severos de funcionamiento o discapacidad tienen 70% más posibilidades de realizar trabajo infantil [RM=1.7, IC95%:1.2,2.4]. El rezago educativo duplica las posibilidades de realizar trabajo infantil [RM=2.2, IC95%:1.5,3.3]. Conclusiones: Es imprescindible garantizar oportunidades educativas y respeto a los derechos de la población infantil con problemas de funcionamiento y discapacidad para lograr su desarrollo integral.

Calcium metabolism of the mother is modified during pregnancy because of the mineralization of the fetus skeleton. OBJECTIVE: To evaluate the association of calcium intake and bone demineralization during pregnancy. MATERIAL AND METHODS: At each trimester of pregnancy a validated food frequency intake questionnaire was administered to assess individual daily calcium intake in a cohort of 206 pregnant women, residents of Mexico City. Samples of urine were collected to measure levels of the cross-linked N-telopeptide of type I collagen (NTx), which is a biomarker of bone resorption. The association between calcium ingestion and bone resorption was analyzed using random effects models; non-linear associations were explored using generalized additive models. RESULTS: Progressive increases in NTx levels were observed during pregnancy; with mean and standard deviation (SD) values during the first, second and third trimester of 76.50 (SD=38), 101.02 (SD=48.86) and 144.83 (SD=61.33) nmol BCE/mmol creatinine, respectively. Higher dietary calcium intake was associated with lower bone resorption (β=-0.015; p<0.05). The association between age and NTx showed a non-linear trend with an inflexion point around 33 years: increase in maternal age below that point was associated with a decrease in bone resorption, while in older women the increase in age was associated with an increased resorption. CONCLUSIONS: Our results suggest that calcium ingestion, specifically from dairy products, reduces bone resorption during pregnancy. For each 300mg (a glass of milk) of calcium intake there is an estimated reduction in NTx level of 4.8 nmol BCE/mmol of creatinine (p<0.05).

El metabolismo de calcio es modificado durante el embarazo debido a la mineralización del esqueleto del feto. OBJETIVO: Evaluar la asociación entre la ingesta de calcio y la desmineralización ósea durante el embarazo. MATERIAL Y MÉTODOS: Se administró un Cuestionario de Frecuencia de Consumo de alimentos en cada trimestre del embarazo para evaluar el consumo de calcio en una cohorte de 206 mujeres residentes de la Ciudad de México. Se recolectaron muestras de orina para medir los niveles de N-telopéptido de colágeno tipo I (NTx), biomarcador de resorción. Se hicieron modelos de efectos aleatorios; se estudiaron asociaciones no lineales utilizando modelos aditivos generalizados. RESULTADOS: Se observó aumento progresivo en los niveles de NTx durante el embarazo. El mayor consumo de calcio se asoció con una menor resorción ósea (β=- 0.015, p<0,05). CONCLUSIONES: Los resultados sugieren que la ingestión de calcio reduce la resorción ósea en el embarazo.

Calcium metabolism of the mother is modified during pregnancy because of the mineralization of the fetus skeleton. OBJECTIVE: To evaluate the association of calcium intake and bone demineralization during pregnancy. MATERIAL AND METHODS: At each trimester of pregnancy a validated food frequency intake questionnaire was administered to assess individual daily calcium intake in a cohort of 206 pregnant women, residents of Mexico City. Samples of urine were collected to measure levels of the cross-linked N-telopeptide of type I collagen (NTx), which is a biomarker of bone resorption. The association between calcium ingestion and bone resorption was analyzed using random effects models; non-linear associations were explored using generalized additive models. RESULTS: Progressive increases in NTx levels were observed during pregnancy; with mean and standard deviation (SD) values during the first, second and third trimester of 76.50 (SD=38), 101.02 (SD=48.86) and 144.83 (SD=61.33) nmol BCE/mmol creatinine, respectively. Higher dietary calcium intake was associated with lower bone resorption (β=-0.015; p<0.05). The association between age and NTx showed a non-linear trend with an inflexion point around 33 years: increase in maternal age below that point was associated with a decrease in bone resorption, while in older women the increase in age was associated with an increased resorption. CONCLUSIONS: Our results suggest that calcium ingestion, specifically from dairy products, reduces bone resorption during pregnancy. For each 300mg (a glass of milk) of calcium intake there is an estimated reduction in NTx level of 4.8 nmol BCE/mmol of creatinine (p<0.05).

El metabolismo de calcio es modificado durante el embarazo debido a la mineralización del esqueleto del feto. OBJETIVO: Evaluar la asociación entre la ingesta de calcio y la desmineralización ósea durante el embarazo. MATERIAL Y MÉTODOS: Se administró un Cuestionario de Frecuencia de Consumo de alimentos en cada trimestre del embarazo para evaluar el consumo de calcio en una cohorte de 206 mujeres residentes de la Ciudad de México. Se recolectaron muestras de orina para medir los niveles de N-telopéptido de colágeno tipo I (NTx), biomarcador de resorción. Se hicieron modelos de efectos aleatorios; se estudiaron asociaciones no lineales utilizando modelos aditivos generalizados. RESULTADOS: Se observó aumento progresivo en los niveles de NTx durante el embarazo. El mayor consumo de calcio se asoció con una menor resorción ósea (β=- 0.015, p<0,05). CONCLUSIONES: Los resultados sugieren que la ingestión de calcio reduce la resorción ósea en el embarazo.