Overweight and obesity status from the prenatal period to adolescence and its association with non-alcoholic fatty liver disease in young adults: cohort study.

OBJECTIVE: To examine the associations of maternal and child overweight status across multiple time-points with liver fat content in the offspring during young adulthood. DESIGN: Cohort study. SETTING: ELEMENT Cohort in Mexico City. POPULATION: Pregnant women with singleton births (n = 97). METHODS: We quantified hepatic triglyceride content (liver fat content) by proton magnetic resonance spectroscopy (1H MRS) and conventional T2-weighted MRIs (3T scanner) in 97 young adults from the ELEMENT birth cohort in Mexico City. Historical records of the cohort were used as a source of pregnancy, and childhood and adolescence anthropometric information, overweight and obesity (OWOB) were defined. Adjusted structural equation models were run to identify the association between OWOB in different life stages with liver fat content (log-transformed) in young adulthood. MAIN OUTCOME: Maternal OWOB at the time of delivery was directly and indirectly associated with the liver fat content in the offspring at young adulthood. RESULTS: Seventeen percent of the participants were classified as having NAFLD. We found a strong association of OWOB between all periods assessed. Maternal OWOB at time of delivery (ß = 1.97, 95% CI 1.28-3.05), and OWOB status in the offspring at young adulthood (ß = 3.17, 95% CI 2.10-4.77) were directly associated with the liver fat content in the offspring. Also, maternal OWOB was indirectly associated with liver fat content through offspring OWOB status. CONCLUSION: We found that maternal OWOB status is related to fatty liver content in the offspring as young adults, even after taking into account OWOB status and lifestyle factors in the offspring. TWEETABLE ABSTRACT: There was an association between pre-pregnancy overweight and the development of NAFLD in adult offspring.

Prenatal lead exposure in relation to age at menarche: results from a longitudinal study in Mexico City.

Animal and cross-sectional epidemiological studies suggest that prenatal lead exposure is related to delayed menarche, but this has not been confirmed in longitudinal studies. We analyzed this association among 200 girls from Mexico City who were followed since the first trimester of gestation. Maternal blood lead levels were analyzed once during each trimester of pregnancy, and daughters were asked about their first menstrual cycle at a visit between the ages of 9.8 and 18.1 years. We estimated hazard ratios (HRs) and 95% confidence intervals (CI) for probability of menarche over the follow-up period using interval-censored Cox models, comparing those with prenatal blood lead level ⩾5 µg/dl to those with prenatal blood lead <5 µg/dl. We also estimated HRs and 95% CI with conventional Cox regression models, which utilized the self-reported age at menarche. In adjusted analyses, we accounted for maternal age, maternal parity, maternal education, and prenatal calcium treatment status. Across trimesters, 36-47% of mothers had blood lead levels ⩾5 µg/dl. Using interval-censored models, we found that during the second trimester only, girls with ⩾5 µg/dl prenatal blood lead had a later age at menarche compared with girls with prenatal blood lead levels <5 µg/dl (confounder-adjusted HR=0.59, 95% CI 0.28-0.90; P=0.05). Associations were in a similar direction, although not statistically significant, in the conventional Cox regression models, potentially indicating measurement error in the self-recalled age at menarche. In summary, higher prenatal lead exposure during the second trimester could be related to later onset of sexual maturation.

Exposure to Bisphenol A and phthalates metabolites in the third trimester of pregnancy and BMI trajectories.

BACKGROUND: Bisphenol A (BPA) and phthalates metabolites are linked to a variety of adverse health consequences but studies have not explored their association with growth trajectories. OBJECTIVE: Explore body mass index (BMI) trajectories for tertile exposures to BPA and phthalates metabolites in the third trimester of pregnancy. METHODS: We constructed BMI (kg/m2 ) trajectories from birth to 14 years in a birth cohort of 249 children from Mexico City using tertiles of third trimester maternal urinary concentrations of BPA and phthalates metabolites. Fractional age polynomials and mixed effects models were fit separately by sex. Predicted models were plotted for each metabolite tertile with the covariates mother's education and BMI centered at average values. RESULTS: Highest predicted BMI trajectories for female children were observed for third tertile exposure to the phthalate metabolite mono(2-ethyl-5-carboxypentyl) phthalate. In male children, first tertile exposure to mono-isobutyl phthalate and monobenzyl phthalate and second tertile exposure to mono(2-ethylhexyl) phthalate and mono(2-ethyl-5-hydroxyhexyl) phthalate predicted the highest BMI trajectory by adolescence. There was no relationshsip between BPA and child growth trajectory. CONCLUSIONS: These results suggest sex-specific differences in BMI trajectories by levels of metabolite exposure. Additional studies are needed to consider growth through adolescence in assessing the association of pregnancy exposures on child's BMI.

Childhood overweight and maternal depressive symptoms.

AIM: Given the rising global prevalence of overweight associated with the nutrition transition, the objective of this study was to evaluate whether maternal depressive symptoms are related to overweight in infants aged 6-24 months. METHODS: Participants in this cross-sectional study included 589 mother-child dyads from low-income urban communities in Teresina, Piauí, northeast Brazil. While adjusting for sociodemographic and biological determinants of child growth, the study assessed the relationship between mothers' depressive symptom scores, measured with the Center for Epidemiologic Studies Depression Scale and child weight-for-height using multivariable logistic regression. Child overweight was calculated with the World Health Organization growth curves using 85th and 95th percentile cutoffs of the weight-for-height z-score (WHZ). RESULTS: Children of mothers with high depressive symptoms had 1.7 and 2.3 higher odds of being over WHZ cutoffs for the 85th and 95th percentile, respectively. Child age between 18 and 24 months (compared with children 6-12 months old), being low birth weight, not receiving the Family Health Programme and breastfeeding between 6 and 12 months (compared with <6 months) were other factors inversely related to at least one of the overweight indicators (odds ratio (OR) range 0.3 to 0.6). Having a mother with fewer than 8 years of education was positively associated with child overweight (OR 1.4, 95% CI 1.0 to 2.1, for WHZ >85th%). CONCLUSION: Results suggest that maternal depressive symptoms are related to overweight in children aged 6-24 months.

Coexistence of maternal central adiposity and child stunting in Mexico.

OBJECTIVE: To assess the coexistence of maternal adiposity and child stunting (CS) in Mexico, estimate its national prevalence and identify the associated socio-demographic factors. METHODS: A secondary analysis from the Mexican Nutrition Survey 1999, a nationally representative survey, was conducted. Mother and children subsamples were matched and a total of 6225 mother/child pairs were obtained. Stunting was defined as height-for-age z-scores <-2.0. Maternal body mass index (BMI) was classified according to World Health Organization recommended cutoff points. Waist-to-hip ratio (WHR) was calculated by dividing waist by hip circumferences. Logistic regression models were fitted to explore the coexistence of CS and maternal central adiposity (MCA) (WHR> or =0.85) while controlling for biological and socio-demographic factors. RESULTS: A total of 5974 pairs had complete information. MCA coexisted with CS in 6.2% of the mother/child pairs. The phenomenon was more prevalent in rural locations, in the south region and among indigenous families (14.5, 12.5 and 23.9%). After controlling for child age and maternal BMI, a 78% increase in the likelihood of CS was related to maternal WHR > or =0.85 (odds ratio (OR)=1.78, 95% confidence interval (CI)=1.53, 2.10). After controlling for maternal height, the magnitude of the OR decreased (OR=1.33, 95%CI=1.13, 1.57), but remained significant. Therefore, it is suggested that women with a WHR approximately 1 have had twice the probability of having a stunted child as those with a WHR of 0.65. CONCLUSION: Although MCA and CS are two conditions frequently regarded as result of opposite determinants, our observation suggests that this is not necessarily the case, particularly in populations undergoing the nutrition transition. MCA was associated not only to chronic diseases, but also to child stunting.

Circumstances of post-neonatal deaths in Ceara, Northeast Brazil: mothers' health care-seeking behaviors during their infants' fatal illness.

Promotion of oral rehydration therapy (ORT) for the treatment of diarrheal diseases and the WHO case management strategy for acute respiratory infections (ARI) have contributed to significant reductions in infant mortality, but these two conditions remain the leading causes of infant deaths in most developing countries. Identification of the factors contributing to these deaths may contribute to reduce infant mortality from preventable causes. To gain insight into the circumstances and maternal and health services factors that may contribute to infant deaths we used a verbal autopsy method to interview mothers of all infants who died during the previous 12 months (June 1995-May 1996) in 11 municipalities in the State of Ceara, Northeast Brazil. Our results revealed that one-third of the deaths occurred in a hospital and two-thirds at home. Almost all the infants who died at home, however, had been examined one or more times by a doctor, and 36% of them had been hospitalized during the disease episode that resulted in death. For most (85%) of these children the causes of death were diarrhea or acute respiratory infection, and it is likely that death could have been averted if appropriate treatment had been initiated promptly. Three major groups of factors that alone or in combination appeared to contribute to most deaths were delays in seeking medical care on behalf of the parents, medical interventions reported as ineffective by mothers and delays in providing medical care to children who arrived at the hospital too late in the day to be scheduled for consultation. Our findings suggest that government efforts to further reduce infant mortality in Ceara should focus on health education interventions that address quality of home care, recognition of signs of severity and danger and importance of seeking timely medical care: and on improving the quality of care provided at community health centers and hospitals. Measures likely to improve infants' chance of survival include: ensuring prompt access to medical consultation for young children brought to health centers or hospitals with potentially life-threatening symptoms related to infections, health education to mothers on the need for continued home care after discharge and to return to the medical care facility if the child does not recover, and that they have access to medicine prescribed by hospital physicians. Further benefits could be obtained by using community health workers, now integrated into the Family Medicine Program (PSF) health teams, to provide health education, supervise home care, refer mothers to health centers and facilitate their access to hospitals.

[Validity and reproducibility of a questionnaire on physical activity and non-activity for school children in Mexico City]. / Validez y reproducibilidad de un cuestionario de actividad e inactividad física para escolares de la ciudad de México.

OBJECTIVE: To assess the validity and reproducibility of a self-reported questionnaire on physical activity and inactivity, developed for children aged 10-14 in Mexico City. MATERIAL AND METHODS: Between May and December 1996, a self-reported physical activity and inactivity questionnaire was developed and applied twice to a sample of 114 students aged 10 to 14, from a low and middle income population of Mexico City. The children's mothers completed the same questionnaire, and two 24-hour recalls of physical activity were used for comparison. Statistical analysis consisted of central tendency and dispersion measures and Pearson's correlation coefficient. RESULTS: Correlations between hours per day spent in physical activity and inactivity from the children's questionnaire and the 24-hour recall data, were 0.03 for moderate activity, 0.15 for vigorous activity, and 0.51 (p = 0.001) for watching television, adjusted by age, gender, town, and illness prior to the administration of the questionnaire. Compared to the 24-hour recall data, the questionnaire overestimated the time spent watching television, reading or participating in vigorous activity, and underestimated the time engaged in moderate activity. Statistically significant (p < 0.05) six-month reproducibility values were observed for watching television (r = 0.53), sleeping (r = 0.40), moderate (r = 0.38), and vigorous activity (r = 0.55). CONCLUSIONS: Among children of Mexico City aged 10-14, the questionnaire showed acceptable validity in estimating the time watching television, and acceptable reproducibility of the time watching television, vigorous and moderate activity.

Determinants of bone and blood lead concentrations in the early postpartum period.

OBJECTIVE: This study investigated determinants of bone and blood lead concentrations in 430 lactating Mexican women during the early postpartum period and the contribution of bone lead to blood lead. METHODS: Maternal venous lead was measured at delivery and postpartum, and bone lead concentrations, measured with in vivo K-x ray fluorescence, were measured post partum. Data on environmental exposure, demographic characteristics, and maternal factors related to exposure to lead were collected by questionnaire. Linear regression was used to examine the relations between bone and blood lead, demographics, and environmental exposure variables. RESULTS: Mean (SD) blood, tibial, and patellar lead concentrations were 9.5 (4.5) microg/dl, 10.2 (10.1) microg Pb/g bone mineral, and 15.2 (15.1) microg Pb/g bone mineral respectively. These values are considerably higher than values for women in the United States. Older age, the cumulative use of lead glazed pottery, and higher proportion of life spent in Mexico City were powerful predictors of higher bone lead concentrations. Use of lead glazed ceramics to cook food in the past week and increased patellar lead concentrations were significant predictors of increased blood lead. Patellar lead concentrations explained one third of the variance accounted for by the final blood lead model. Women in the 90th percentile for patella lead had an untransformed predicted mean blood lead concentration 3.6 microg/dl higher than those in the 10th percentile. CONCLUSIONS: This study identified the use of lead glazed ceramics as a major source of cumulative exposure to lead, as reflected by bone lead concentrations, as well as current exposure, reflected by blood lead, in Mexico. A higher proportion of life spent in Mexico City, a proxy for exposure to leaded gasoline emissions, was identified as the other major source of cumulative lead exposure. The influence of bone lead on blood lead coupled with the long half life of lead in bone has implications for other populations and suggests that bone stores may pose a threat to women of reproductive age long after exposure has declined.

Association of maternal short stature with stunting in Mexican children: common genes vs common environment.

OBJECTIVE: To evaluate the association between stunting in children and maternal short stature, controlling for potential environmental confounders. DESIGN: 1988 Mexico National Nutrition Survey. SETTING: Mexico SUBJECTS: The final sample size was 4663 pairs of children (<5 y) and their mothers (12-49 y) from a total of 13 236 surveyed houses. MAIN OUTCOME MEASURES: Stunting (height-for-age Z-scores <-2). RESULTS: The prevalence of stunting in children was 19%, and 10% of the mothers exhibited short stature (<145 cm). In the crude analysis, mothers with short stature were significantly more likely to have stunted children (odds ratio (OR)=4.0; 95% confidence interval (CI)=3.2-4.8; P-value <0.001). In a multiple logistic regression model the OR for child stunting was reduced, but remained significant OR=2.0; 95% CI=1.6-2.6; P-value <0.001) after adjustment for region, urban/rural residence, socio-economic status, household size, child age and presence of infection in the past 14 d, and maternal age, body mass index (BMI), and educational level. Adjusted ORs varied between regions (Mexico City, OR=3.9; North Mexico, OR=3. 1; Central Mexico, OR=2.0; South Mexico, OR=1.6. Comparison of crude vs adjusted estimates pointed to regional differences in the proportion of association between maternal and child short statures explained by environmental determinants. CONCLUSIONS: Maternal stature, reflecting her potential height and early environment, appeared to contribute to child height independently of the shared risk factors that could affect stature. Nonetheless, we could explain much of the association between stunting in children and maternal short stature by environmental factors, and part of the residual variability may be due to unmeasured determinants. Regional differences pointed to a predominance of environmental factors in explaining child stunting in poorer regions.

Relationship between health services, socioeconomic variables and inadequate weight gain among Brazilian children.

This ecological analysis assessed the relative contribution of behavioural, health services and socioeconomic variables to inadequate weight gain in infants (0-11 months) and children (12-23 months) in 140 municipalities in the State of Ceara, north-east Brazil. To assess the total effect of selected variables, we fitted three unique sets of multivariate linear regression models to the prevalence of inadequate weight gain in infants and in children. The final predictive models included variables from the three sets. Findings showed that participation in growth monitoring and urbanization were inversely and significantly associated with the prevalence of inadequate weight gain in infants, accounting for 38.3% of the variation. Female illiteracy rate, participation in growth monitoring and degree of urbanization were all positively associated with prevalence of inadequate weight gain in children. Together, these factors explained 25.6% of the variation. Our results suggest that efforts to reduce the average municipality-specific female illiteracy rate, in combination with participation in growth monitoring, may be effective in reducing municipality-level prevalence of inadequate weight gain in infants and children in Ceara.

PIP: This article assesses the relationship between health services, socioeconomic variables, and inadequate weight gain among Brazilian children. The study used ecological analysis to assess the relative contributions of these variables to variations in the prevalence of inadequate weight gain among infants and young children in 140 municipalities in the State of Caera, northeast Brazil. The assessment of the total effect of selected variables involved fitting three unique sets of multivariate linear regression models to the prevalence of inadequate weight gain among infants and children. Findings showed several significant predictors of the prevalence of inadequate weight gains. These include participation in growth monitoring and a degree of urbanization, which together account for 38.3% of the variation, and female illiteracy rate (9.7% of the variation). Overall, these factors explain 25.6% of the variation in child growth. In conclusion, the study suggests that efforts to reduce the average municipality-specific female illiteracy rate, in combination with participation in growth monitoring may be effective in reducing municipality-level prevalence of inadequate weight gain among infants and children in Caera.

Association of obesity with physical activity, television programs and other forms of video viewing among children in Mexico city.

OBJECTIVE: To assess the association of physical activity, television program viewing and other forms of video viewing with the prevalence of obesity among school children. DESIGN: Cross-sectional study. SUBJECTS: 712 children, 9-16 y old, from a low- and a middle-income town in the Mexico City area. MEASUREMENTS: Children completed a self administered questionnaire to assess time spent in physical activity and television viewing, and diet. Height weight and triceps skinfolds were measured. The outcome variable was obesity, and the covariates were hours of television programs and other video viewing, physical activity, energy intake, percentage of energy from fat, town of location of school, age, gender and perception of mother's weight status. RESULTS: Among 461 children with complete information, 24% were classified as obese. Children reported an average of 4.1 +/- 2.2 h/d watching television (2.4 +/- 1.5 h/d for TV programs and 1.7 +/- 1.5 h/d for video cassette recorder (VCR) or videogames), and 1.8 +/- 1.3 h/d in moderate and vigorous physical activities. Odds ratios (OR) of obesity were 12% higher for each hour of television program viewing per day (OR = 1.12, 95% confidence interval (CI) 1.02,-1.22), and 10% lower for each hour of moderate/vigorous physical activity per day (OR = 0.90, 95% CI 0.83-0.98), controlling for age, gender, town and perception of mother's weight status. Children in the middle-income town had higher adjusted odds of obesity (OR = 2.58, 95% CI 1.47-4.54). CONCLUSION: Physical activity and television viewing, but not VCR/videogames use, were related to obesity prevalence in Mexican children 9-16 y old.

Variations in infant mortality rates among municipalities in the state of Ceará, Northeast Brazil: an ecological analysis.

BACKGROUND: Infant mortality rates vary substantially among municipalities in the State of Ceará, from 14 to 193 per 1000 live births. Identification of the determinants of these differences can be of particular importance to infant health policy and programmes in Brazil where local governments play a pivotal role in providing primary health care. METHODS: Ecological study across 140 municipalities in the State of Ceará, Brazil. RESULTS: To determine the interrelationships between potential predictors of infant mortality, we classified 11 variables into proximate determinants (adequate weight gain and exclusively breastfeeding), health services variables (prenatal care up-to-date, participation in growth monitoring, immunization up-to-date, and decentralization of health services), and socioeconomic factors (female literacy rate, household income, adequate water supply, adequate sanitation, and per capita gross municipality product), and included the variables in each group simultaneously in linear regression models. In these analyses, only one of the proximate determinants (exclusively breastfeeding (inversely), R2 = 9.3) and one of the health services variables (prenatal care up-to-date (inversely), R2 = 22.8) remained significantly associated with infant mortality. In contrast, female literacy rate (inversely), household income (directly) and per capita GMP (inversely) were independently associated with the infant mortality rate (for the model including the three variables R2 = 25.2). Finally, we considered simultaneously the variables from each group, and selected a model that explained 41% of the variation in infant mortality rates between municipalities. The paradoxical direct association between household income and infant mortality was present only in models including female illiteracy rate, and suggests that among these municipalities, increases in income unaccompanied by improvements in female education may not substantially reduce infant mortality. The lack of independent associations between inadequate sanitation and infant mortality rates may be due to the uniformly poor level of this indicator across municipalities and provides no evidence against its critical role in child survival. CONCLUSIONS: These results suggest that promotion of exclusive breastfeeding and increased prenatal care utilization, as well as investments in female education would have substantial positive effects in further reducing infant mortality rates in the State of Ceará.

Dietary and environmental determinants of blood and bone lead levels in lactating postpartum women living in Mexico City.

Despite the recent declines in environmental lead exposure in the United States and Mexico, the potential for delayed toxicity from bone lead stores remains a significant public health concern. Some evidence indicates that mobilization of lead from bone may be markedly enhanced during the increased bone turnover of pregnancy and lactation, resulting in lead exposure to the fetus and the breast-fed infant. We conducted a cross-sectional investigation of the interrelationships between environmental, dietary, and lifestyle histories, blood lead levels, and bone lead levels among 98 recently postpartum women living in Mexico City. Lead levels in the patella (representing trabecular bone) and tibia (representing cortical bone) were measured by K X-ray fluorescence (KXRF). Multivariate linear regression models showed that significant predictors of higher blood lead included a history of preparing or storing food in lead-glazed ceramic ware, lower milk consumption, and higher levels of lead in patella bone. A 34 micrograms/g increase in patella lead (from the medians of the lowest to the highest quartiles) was associated with an increase in blood lead of 2.4 micrograms/dl. Given the measurement error associated with KXRF and the extrapolation of lead burden from a single bone site, this contribution probably represents an underestimate of the influence of trabecular bone on blood lead. Significant predictors of bone lead in multivariate models included years living in Mexico City, lower consumption of high calcium content foods, and nonuse of calcium supplements for the patella and years living in Mexico City, older age, and lower calcium intake for tibia bone. Low consumption of milk and cheese, as compared to the highest consumption category (every day), was associated with an increase in tibia bone lead of 9.7 micrograms Pb/g bone mineral. The findings of this cross-sectional study suggest that patella bone is a significant contributor to blood lead during lactation and that consumption of high calcium content foods may protect against the accumulation of lead in bone.