Height Trajectory During Early Childhood Is Inversely Associated with Fat Mass in Later Childhood in Mexican Boys.

BACKGROUND: Childhood obesity continues to be a global health problem. Previous research suggests that linear growth retardation or stunting during early childhood increases the risk of obesity, but others have reported that rapid linear growth poses a greater concern than early nutritional status. OBJECTIVE: The objective of this study was to determine if growth trajectories are associated with body composition at age 8-10 y. METHODS: Study participants consisted of 255 girls and 281 boys who participated in a follow-up of the Prenatal Omega-3 Fatty Acid Supplementation and Child Growth and Development (POSGRAD) Study. Sex-specific latent height class (LHC) trajectories were derived from 11 measures of height from birth to 5 y of age and used to calculate 3 distinct growth classes for boys (low, intermediate, and high) and 2 distinct classes for girls (low and high). Body composition at age 8-10 y was estimated using bioelectrical impedance analysis. Multivariable linear regression analysis was used to determine the relationship between growth trajectory classes and fat mass (FM) and fat-free mass (FFM) in late childhood, controlling for confounding factors. RESULTS: In girls, there were no significant associations between LHC and FM or FFM. In boys, relative to the intermediate LHC, the low LHC had higher FM (ß = 0.69 kg; 95% CI: 0.26-1.11 kg) and the high LHC had lower FM (ß = -0.40 kg; 95% CI: -0.76 to -0.05 kg). Boys in the low LHC had significantly less FFM (ß = -0.69 kg; 95% CI: -1.11 to -0.26 kg), and boys in the high LHC had more FFM (ß = 0.40 kg; 95% CI: 0.05-0.76 kg) compared with the intermediate LHC. CONCLUSION: Gain in height among boys, but not girls, in early childhood was associated with lower adiposity in late childhood compared with children with a slower rate of growth. Clinical trial registration number: NCT00646360.

Serum 25-hydroxyvitamin D and breast cancer risk by pathological subtype (MCC-Spain).

Epidemiologic evidence on the association between vitamin D and breast cancer is still inconclusive. This study analyzes the association between serum 25-hydroxyvitamin D (25(OH)D) and breast cancer risk by pathologic subtype, stage at diagnosis and specific breast cancer risk factors. We conducted a population-based multicase-control study where 546 histologically-confirmed breast cancer cases and 558 population controls, frequently matched by geographic area, age and body mass index, were recruited in 12 Spanish provinces (MCC-Spain). Information was collected by a questionnaire and plasma 25(OH)D was measured by solid-phase extraction on-line coupled to liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS). Odds ratios and 95% confidence intervals were calculated using logistic and multinomial mixed regression models. We found a clear protective effect between 25(OH)D levels and breast cancer risk, with a significant dose-response trend (OR per 10 nmol/L = 0.88; 95%CI = 0.82-0.94). While no differences were observed between pre and postmenopausal women, stage at diagnosis, or across strata of the main breast cancer risk factors, the protection was more pronounced for triple negative tumors (OR per 10 nmol/L = 0.64; p-heterogeneity = 0.038). Similar results were observed when only cases sampled in the first month after diagnosis were considered. The protective effect of vitamin D on breast cancer risk may be subtype specific, being stronger for more aggressive tumors, which provides a new approach to prevent this disease.

Higher metabolic syndrome in obese asthmatic compared to obese nonasthmatic adolescent males.

UNLABELLED: The relationship between asthma and obesity has been documented in children and adolescents; however, few studies on metabolic syndrome and asthma have been performed. OBJECTIVE: To determine the prevalence of metabolic syndrome in adolescents among the following groups: obese with asthma (OA), obese without asthma (ONA), nonobese with asthma (NOA), and nonobese without asthma (NONA). PATIENTS AND METHODS: The authors measured anthropometric (height, weight, waist circumference, body mass index, and waist-hip ratio), clinical (Tanner stage, blood pressure, fat and muscle reserve, and exercise), and biochemical parameters (basal and load glucose, cholesterol, triglycerides, high-density lipoproteins, uric acid, and insulin) in 500 Mexican adolescents. RESULTS: A total of 111 OA, 198 ONA, 63 NOA, and 71 NONA adolescents completed the study. There were no differences in age, height, Tanner stage, high-density lipoproteins, or basal glucose among groups. Cholesterol, triglycerides, uric acid, basal insulin, and homeostasis model assessment (HOMA)-IR were significantly higher among the obese than nonobese groups but were similar between the OA and ONA groups. The prevalence of impaired fasting glucose was significantly higher among ONA versus OA males. The prevalence of metabolic syndrome (define as > or =3 abnormal cardiometabolic risk factors by de Ferranti, Cook, and International Diabetes Federation [IDF] criteria) was higher among OA teens than in the ONA group; however, this association was significant only among males. Adolescents from the ONA group were able to perform significantly more vigorous exercise than the other groups. CONCLUSION: Adolescent males who were obese and also had mild persistent asthma had a significantly higher prevalence of metabolic syndrome than obese males without asthma. However, overall, asthma seems to confer a protective effect against the prediabetes condition in males.

Cáncer de mama. Un hilo conductor histórico presente y futuro / Breast cancer: a historical account, present and future

Se describen los modelos que tradicionalmente han sido utilizados en la construcción teórica del conocimiento de cáncer de mama (CM); es decir, el biologicista, el higienista-preventivo y el epidemiológico. Se incluye además -en forma anecdótica- el modelo hipocrático. El CM se perfila como una amenaza letente en países como México a consecuencia del aumento importante de la esperanza de vida; de la reducción de la tasa de crecimiento total anual, al inicio de lo que hoy conocemos como el proceso de envejecimiento de la población; de cambios en los estilos de vida, particularmente la práctica cada vez menor de la lactancia y la disminución de tasas de fertilidad; así como de la escasa eficiencia y efectividad de los programas de detección oportuna del CM. En este contexto, uno de los principales retos en relación con este padecimiento es la práctica de la salud pública con fundamento multidisciplinario. Al final de este ejercicio, se propone el modelo sociomédico, que postula la integración de diversas áreas del conocimiento y permite dar una respuesta efectiva a uno de los principales desafíos en materia de enfermedades crónicas de los próximos años

This essay describes the different theoretical constructions of breast cancer models, such as the biological, hygienist-preventive and epidemiological. An anecdotical account of the Hippocratic model is also presented. This disease will be one of the major challenges posed by noncommunicable diseases in coming years, due to a significant increase of life expectancy and to a decrease of the overall annual growth rate -resulting in the ageing of the population-, as well as to lifestyle changes -particularly the considerable decrease of fertility rates and breastfeeding practices-, and to the poor efficiency and effectiveness of breast cancer screening programs. In this context, one of the main challenges for breast cancer control is to secure the multidisciplinary approach offered by public health. After analyzing the different models, we favor the sociomedical model as the one that incorporates several areas of knowledge to formulate an effective response to breast cancer.

Estudio de validación y reproducibilidad de monitores pasivos a ozono / Evaluation of the validity and reproducibility of passive ozone monitors

El objetivo de este estudio fue estimar la validez y reproducibilidad entre las mediciones de monitores pasivos a ozono con las registradas por un monitor continuo, para así poder determinar la aplicabilidad de los monitores en investigación epidemiológica y llega a contar con patrones de exposición más detallados de los efectos crónicos y agudos causados por ozono. Las pruebas fueron realizadas durante los meses de noviembre y diciembre de 1992. Consistieron en exponer 28 monitores pasivos al aire ambiental presente en el interior y exterior de un salón de clases, al mismo tiempo que se registraba la concentración de ozono mediante un monitor continuo. La correlación entre ambas lecturas fue altamente significativa (r= 0.89, p< 0.001), lo cual indica que el monitor pasivo registra concentraciones muy cercanas a las de monitor continuo. Asimismo, la correlación entre las lecturas de los monitores pasivos expuestos simultáneamente también fue alta (r= 0.97, p< 0.001), lo que significa una buena reproducibilidad en las mediciones por monitores pasivos a ozono. El error relativo entre las mediciones de los manitores pasivos y el monitor continuo fue disminuyendo conforme se incrementaban las concentraciones de ozono. Los resultados indican que es recomendable usar los monitores pasivos para mediciones acumulativas de ozono mayores a 100 ppb, lo que implica periodos de medición mayores a cinco días cuando son utilizados en interiores