Objetivo. Describir la prevalencia de obesidad en adultosmexicanos estratificando por condiciones físicas y sociodemográficas,y analizar tendencias. Material y métodos.Análisis de 16 256 adultos de la Encuesta Nacional de Salud yNutrición (Ensanut) 2018-19. Se clasificó obesidad (OMS), adiposidadabdominal (IDF) y talla baja (NOM-008-SSA3-2017).Se realizaron modelos de regresión logística para asociarobesidad y factores de riesgo. Para evaluar tendencias seanalizaron Encuesta Nacional de Salud 2000 y Ensanut (2006,2012, 2018-19). Resultados. La prevalencia de sobrepesofue 39.1%, obesidad 36.1% y adiposidad abdominal 81.6%. Sepresentaron las prevalencias más altas en >40-50 años y enlas mujeres. No hubo diferencia por nivel socioeconómico.En el periodo 2000-2018 aumentó la prevalencia de obesidad42.2% y de obesidad mórbida 96.5%. Las mujeres con tallabaja tuvieron mayor riesgo (RM=1.84) de tener obesidad quelas mujeres sin esta condición, mientras que en hombres elriesgo fue menor (RM=0.79). Conclusiones. En México,la prevalencia de obesidad sigue aumentando sin importarnivel socioeconómico, región o localidad.

Objectives The aim of the present study was to estimate the incidence and spontaneous clearance rate of Helicobacter pylori infection and the effect of some variables on these outcomes in schoolchildren. Methods From May 2005 to December 2010, 718 schoolchildren enrolled in 3 public boarding schools in Mexico City participated in the follow-up. At the beginning of the study and every 6 months thereafter, breath samples were taken to detect H pylori infection; blood samples and anthropometric measurements were taken to evaluate nutritional status. Data on sociodemographic characteristics were collected. Results The prevalence of H pylori infection was 38%. The incidence rate was 6.36%/year. Schoolchildren with anemia or iron deficiency at the beginning of the study (who received iron supplements) showed a higher infection acquisition rate than those with normal iron nutritional status, hazard ratio (HR) 12.52 (95% confidence interval [CI] 4.01%–39.12%), P <0.001 and HR 2.05 (95% CI 1.09%–3.87%), P = 0.027, respectively. The spontaneous clearance rate of the infection was 4.74%/year. The spontaneous clearance rate was higher in children who had iron deficiency (who received iron supplements), HR 5.02 (95% CI 1.33%–18.99%), P = 0.017, compared with those with normal nutritional iron status. It was lower in schoolchildren with ≥2 siblings compared with schoolchildren with 1 or no siblings, HR 0.23 (95% CI 0.08%–0.63%), P = 0.004. Conclusions H pylori infection status is dynamic in schoolchildren. Variables related to health status and infection transmission, such as iron status and number of siblings, are important for the incidence and spontaneous clearance of H pylori infection.

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Objective. To estimate the incidence of type 2 diabetes (T2D) in Mexican population. Materials and methods. Population based prospective study. At baseline (1990), the population at risk (1939 non-diabetic adults 35-64 years) was evaluated with oral glucose tolerance test. Subsequent similar evaluations were done (1994, 1998, 2008). American Diabetes Association diagnostic criteria were applied. Re­sults. The period of observation was 27842 person-years, the cumulative incidence of T2D was 14.4 and 13.7 per 1000 person-years for men and women, respectively. Incidence was 15.8, 15.7 and 12.7 per 1 000 person-years for the second (1994), third (1998) and fourth (2008) follow-up phases, respectively. The mean age at diagnosis was 44 years for prevalent cases and 56 years for incident cases. Conclu­sions. This is the first estimate of long-term incidence of T2D in Mexican population. The incidence is among the highest reported worldwide. It remained with few changes throughout the study period.

Background Lead and psychosocial stress disrupt similar but not completely overlapping mechanisms. Exposure during the prenatal period to each of these insults singularly has been found to alter normal neurodevelopment; however, longitudinal associations with stress modifying the effect of lead have not been sufficiently analyzed in epidemiologic studies. Objective To evaluate prenatal stress as an effect modifier of gestational lead neurotoxicity. Methods We used a structural equations modeling approach with a trivariate response to evaluate cognitive, language and motor scores of the Bayley Scales of Infant Development-III in 24 month-old children (n=360). Maternal blood lead levels were measured at the 2nd and 3rd trimester and psychosocial stress during pregnancy was assessed using a negative life events (NLE) scale derived from the CRYSIS questionnaire. Results 3rd trimester lead (mean 3.9 ± 3.0 SD μg/dL) and stress (median=3 NLE) were negatively associated with Bayley III scores. Using the model's results we generated profiles for 0, 2, 4 and 6 NLE across lead levels (up to 10 μg/dL) and observed a dose-response for the developmental scores when lead levels were below 2 μg/dL. Each NLE curve had a different shape across increasing lead levels. Higher stress (NLE=6) resulted in lower cognitive scores for both sexes, in lower language scores in girls but not boys. In the absence of stress we saw a negative association with lead for all scores, however for language and motor scores, higher stress seemed to mask this association. Conclusions Our work examined and confirmed prenatal stress exposure as a modifier of the well-known neurotoxic effects of prenatal lead. It adds to the existing evidence pointing at the importance of studying the co-exposure of chemical and non-chemical exposures, specifically of considering the emotional environment of children at early developmental stages of life.

EBF and PreBF at 3 mo were associated with lower adiposity and serum total cholesterol in children at 4 y. In addition, BF >12 mo was associated with lower adiposity. These data confirm the importance of exclusive BF and prolonged BF for later cardiometabolic health.

Various individual and regional factors were associated with variations in the prevalence of RA in the Mexican population.

BackgroundBlood lead has been associated with an elevated risk of miscarriage. The plasmatic fraction of lead represents the toxicologically active fraction of lead. Women with a tendency to have a higher plasma/whole blood Pb ratio could tend towards an elevated risk of miscarriage due to a higher plasma Pb for a given whole blood Pb and would consequently have a history of spontaneous abortion.MethodsWe studied 207 pregnant Mexico City residents during the 1st trimester of pregnancy, originally recruited for two cohorts between 1997 and 2004. Criteria for inclusion in this study were having had at least one previous pregnancy, and having valid plasma and blood Pb measurements. Pb was measured in whole blood and plasma by inductively coupled plasma mass spectrometry using ultra-clean techniques. History of miscarriage in previous pregnancies was obtained by interview. The incidence rate of spontaneous abortion was defined as the proportion of previous pregnancies that resulted in miscarriage. Data were analyzed by means of Poisson regression models featuring the incidence rate of spontaneous abortion as the outcome and continuous or categorized plasma/blood Pb ratios as predictor variables. All models were adjusted for age and schooling. Additionally, logistic regression models featuring inclusion in the study sample as the outcome were fitted to assess potential selection bias.ResultsThe mean number of miscarriages was 0.42 (range 0 to 4); mean Pb concentrations were 62.4 and 0.14 μg/L in whole blood and plasma respectively. Mean plasma/blood Pb ratio was 0.22%. We estimated that a 0.1% increment in the plasma/blood Pb ratio lead was associated to a 12% greater incidence of spontaneous abortion (p = 0.02). Women in the upper tertile of the plasma/blood Pb ratio had twice the incidence rate of those in the lower tertile (p = 0.02). Conditional on recruitment cohort, inclusion in the study sample was unrelated to observable characteristics such as number of abortions, number of pregnancies, blood Pb levels, age schooling, weight and height.ConclusionWomen with a large plasma/whole blood Pb ratio may be at higher risk of miscarriage, which could be due to a greater availability of placental barrier-crossing Pb.