Parental Separation and Cardiometabolic Risk Factors in Late Adolescence: A Cross-Cohort Comparison.

The aim of this study was to explore the association between parental separation during childhood (up to 18 years of age) and cardiometabolic risk factors (body mass index, fat mass index, blood pressure, physical activity, smoking, and alcohol consumption) in late adolescence using a cross-cohort comparison and to explore whether associations differ according to the age at which the parental separation occurred and the presence or absence of parental conflict prior to separation. Data from the Avon Longitudinal Study of Parents and Children (ALSPAC, United Kingdom) (1991-2011) and the 1993 Pelotas Birth Cohort (Brazil) (1993-2011) were used. The associations of parental separation with children's cardiometabolic risk factors were largely null. Higher odds of daily smoking were observed in both cohorts for those adolescents whose parents separated (for ALSPAC, odds ratio = 1.46; for Pelotas Birth Cohort, odds ratio = 1.98). Some additional associations were observed in the Pelotas Birth Cohort but were generally in the opposite direction to our a priori hypothesis: Parental separation was associated with lower blood pressure and fat mass index, and with more physical activity. No consistent differences were observed when analyses were stratified by child's age at parental separation or parental conflict.

Association of lactase persistence genotype with milk consumption, obesity and blood pressure: a Mendelian randomization study in the 1982 Pelotas (Brazil) Birth Cohort, with a systematic review and meta-analysis.

BACKGROUND: Milk intake has been associated with lower blood pressure (BP) in observational studies, and randomized controlled trials suggested that milk-derived tripeptides have BP-lowering effects. Milk intake has also been associated with body mass index (BMI). Nevertheless, it is unclear whether increasing milk consumption would reduce BP in the general population. METHODS: We investigated the association of milk intake with obesity and BP using genetically-defined lactase persistence (LP) based on the rs4988235 polymorphism in a Mendelian randomization design in the 1982 Pelotas (Southern Brazil) Birth Cohort. These results were combined with published reports identified through a systematic review using meta-analysis. RESULTS: In the 1982 Pelotas Birth Cohort, milk intake was 42 [95% confidence interval (CI): 18; 67) ml/day higher in LP individuals. In conventional observational analysis, each 1-dl/day increase in milk intake was associated with -0.26 (95% CI: -0.33; -0.19) kg/m2 in BMI and -0.31 (95% CI: -0.46; -0.16) and -0.35 (95% CI: -0.46; -0.23) mmHg in systolic and diastolic BP, respectively. These results were not corroborated when analysing LP status, but confidence intervals were large. In random effects meta-analysis, LP individuals presented higher BMI [0.17 (95% CI: 0.07; 0.27) kg/m2] and higher odds of overweight-obesity [1.09 (95% CI: 1.02; 1.17)]. There were no reliable associations for BP. CONCLUSIONS: Our study supports that LP is positively associated with obesity, suggesting that the negative association of milk intake with obesity is likely due to limitations of conventional observational studies. Our findings also do not support that increased milk intake leads to lower BP.

Reduced or modified dietary fat for preventing cardiovascular disease.

BACKGROUND: Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear. OBJECTIVE: To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration. SEARCH METHODS: For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase, were searched through to June 2010. References of Included studies and reviews were also checked. SELECTION CRITERIA: Trials fulfilled the following criteria: 1) randomized with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. DATA COLLECTION AND ANALYSIS: Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed. MAIN RESULTS: This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I2 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis. Few studies compared reduced with modified fat diets, so direct comparison was not possible. AUTHORS' CONCLUSIONS: The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.

Reduced or modified dietary fat for preventing cardiovascular disease

ABSTRACT: BACKGROUND: Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear. OBJECTIVE: To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration. METHODS: Search methods: For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase, were searched through to June 2010. References of Included studies and reviews were also checked. Selection criteria: Trials fulfilled the following criteria: 1) randomized with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. Data collection and analysis: Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed. MAIN RESULTS: This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I2 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis. Few studies compared reduced with modified fat diets, so direct comparison was not possible. AUTHORS' CONCLUSIONS: The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.

Does Breast-Feeding in Infancy Lower Blood Pressure in Childhood?

Background: Breast-feeding in infancy has been associated with decreased coronary heart disease mortality, but the underlying mechanisms are unclear. We investigated the association of breast-feeding with blood pressure in a contemporary cohort...

Does breast-feeding in infancy lower blood pressure in childhood? The Avon Longitudinal Study of Parents and Children (ALSPAC)

Breast-feeding in infancy has been associated with decreased coronary heart disease mortality, but the underlying mechanisms are unclear...

Effect of infant feeding on the risk of obesity across the life course: a quantitative review of published evidence

Objective: To examine the influence of initial infant feeding on obesity in later life...

Does breastfeeding influence risk of type 2 diabetes in later life? A quantitative analysis of published evidence

The objective was to examine the influence of initial breastfeeding on type 2 diabetes and blood glucose and insulin concentrations...

Does initial breastfeeding lead to lower blood cholesterol in adult life? A quantitative review of the evidence

Objective: We aimed to examine whether breastfeeding is associated with lower blood cholesterol concentrations in adulthood...

What are the causal effects of breastfeeding on IQ, obesity and blood pressure? Evidence from comparing high-income with middle-income cohorts.

BACKGROUND: A novel approach is explored for improving causal inference in observational studies by comparing cohorts from high-income with low- or middle-income countries (LMIC), where confounding structures differ. This is applied to assessing causal effects of breastfeeding on child blood pressure (BP), body mass index (BMI) and intelligence quotient (IQ). METHODS: Standardized approaches for assessing the confounding structure of breastfeeding by socio-economic position were applied to the British Avon Longitudinal Study of Parents and Children (ALSPAC) (N ≃ 5000) and Brazilian Pelotas 1993 cohorts (N ≃ 1000). This was used to improve causal inference regarding associations of breastfeeding with child BP, BMI and IQ. Analyses were extended to include results from a meta-analysis of five LMICs (N ≃ 10 000) and compared with a randomized trial of breastfeeding promotion. Findings Although higher socio-economic position was strongly associated with breastfeeding in ALSPAC, there was little such patterning in Pelotas. In ALSPAC, breastfeeding was associated with lower BP, lower BMI and higher IQ, adjusted for confounders, but in the directions expected if due to socioeconomic patterning. In contrast, in Pelotas, breastfeeding was not strongly associated with BP or BMI but was associated with higher IQ. Differences in associations observed between ALSPAC and the LMIC meta-analysis were in line with those observed between ALSPAC and Pelotas, but with robust evidence of heterogeneity detected between ALSPAC and the LMIC meta-analysis associations. Trial data supported the conclusions inferred by the cross-cohort comparisons, which provided evidence for causal effects on IQ but not for BP or BMI. CONCLUSION: While reported associations of breastfeeding with child BP and BMI are likely to reflect residual confounding, breastfeeding may have causal effects on IQ. Comparing associations between populations with differing confounding structures can be used to improve causal inference in observational studies.

Differentials and income-related inequalities in maternal depression during the first two years after childbirth: birth cohort studies from Brazil and the UK.

BACKGROUND: Depression is a prevalent health problem among women during the childbearing years. To obtain a more accurate global picture of maternal postnatal depression, studies that explore maternal depression with comparable measurements are needed. The aims of the study are: (1) to compare the prevalence of maternal depression in the first and second year postpartum between a UK and Brazilian birth cohort study; (2) to explore the extent to which variations in the rates were explained by maternal and infant characteristics, and (3) to investigate income-related inequalities in maternal depression after childbirth in both settings. METHODS: Population-based birth cohort studies were carried out in Avon, UK in 1991 (ALSPAC) and in the city of Pelotas, Brazil in 2004, where 13 798 and 4109 women were analysed, respectively. Self-completion questionnaires were used in the ALSPAC study while questionnaires completed by interviewers were used in the Pelotas cohort study. Three repeated measures of maternal depression were obtained using the Edinburgh Postnatal Depression Scale in the first and second year after delivery in each cohort. Unadjusted and adjusted analyses were carried out. The Relative index of Inequality was used for the analysis of income-relate inequalities so that results were comparable between cohorts. RESULTS: At both the second and third time assessments, the likelihood of being depressed was higher among women from the Pelotas cohort study. These differences were not completely explained by differences in maternal and infant characteristics. Income-related inequalities in maternal depression after childbirth were high and of similar magnitude in both cohort studies at the three time assessments. CONCLUSION: The burden of maternal depression after childbirth varies between and within populations. Strategies to reduce income-related inequalities in maternal depression should be targeted to low-income women in both developed and developing countries.

Socioeconomic position and overweight among adolescents: data from birth cohort studies in Brazil and the UK.

BACKGROUND: Developed and developing countries are facing rapid increases in overweight and obesity among children and adolescents. The patterns of overweight/obesity differ by age, sex, rural or urban residence and socioeconomic position (SEP) and vary between and within countries. METHODS: We investigated patterns of SEP--overweight status association among adolescents from the UK (ALSPAC) and Brazil (the 1982 and 1993 Pelotas birth cohort studies). All analyses were performed separately for males and females. Logistic regression analysis was used to examine the relationships between overweight status and two SEP indicators--family income and maternal education. RESULTS: A strong positive association was observed in 11-year-old boys from the 1993 Pelotas cohort, with higher prevalence of overweight among the least poor and among those whose mothers had more years of schooling (x2 for linear trend p < 0.001). In ALSPAC study higher prevalence of overweight was seen among boys whose mothers had lower educational achievement (x2 for linear trend p = 0.006). Among 11 year-old girls from 1993 Pelotas cohort study there was a positive association (higher prevalence of overweight in the higher socioeconomic and educational strata, x2 for linear trend p < 0.001 and p = 0.01, respectively) while an inverse association was found in the ALSPAC study (x2 for linear trend p < 0.001). Among males from the 1982 cohort study, overweight at 18 years of age showed a positive association with both SEP indicators while among females, the reverse association was found. CONCLUSION: The results of this study demonstrate that the social patterning of overweight varies between and within populations over time. Specific approaches should be developed within populations in order to contain the obesity epidemic and reduce disparities.

Frequency of diarrhoea as a predictor of elevated blood pressure in children.

BACKGROUND: Diarrhoeal illness is a major public health problem for children worldwide, particularly among developing countries, and is a proxy condition for severe dehydration. It has been hypothesized that severe dehydration in the first 6 months of life could be associated with increased blood pressure later in life. This study aimed to explore whether frequency of diarrhoea is associated with elevated blood pressure in children in a setting with a high incidence of diarrhoeal disease. METHODS: The present study is a cross-sectional study of blood pressure among children from a longitudinal child diarrhoeal disease cohort in Lima, Peru. From 2001 to 2006, daily diarrhoeal surveillance was made. Children were revisited in 2006 and blood pressure was measured. Diarrhoeal exposures were evaluated in terms of total number of diarrhoea days, number of episodes of diarrhoea, persistent diarrhoeal episodes and by the quartiles of daily incidence and episode incidence of diarrhoea. RESULTS: The overall incidence of diarrhoeal episodes at age under 1 year was 4.35 (95% confidence interval: 3.79-4.98) and under 5 years was 2.80 (95% confidence interval: 2.69-2.92). No association was observed between the total number of diarrhoeal days, diarrhoeal episodes or diarrhoeal incidence rates with childhood blood pressure. There was weak evidence that hospital admission due to severe dehydration in the first year of life showed a gradient towards an increase in both, systolic and diastolic blood pressure. CONCLUSION: In the first study to date to examine the association in a setting with a high incidence of diarrhoeal disease, diarrhoeal frequency did not show an association with increased blood pressure. Our observations of elevated levels of blood pressure among those admitted into hospitals in the first year of life are in line with the original hypothesis of dehydration in early infancy and high blood pressure. However, the effect of episodes of severe dehydration on later blood pressure remains uncertain.

Obesidad y mortalidad en hombres según el estado de su enfermedad coronaria / Obesity and mortality in men according to coronary heart disease status

Las pocas comunicaciones sobre la asociación de obesidad o sobrepeso con mortalidad en personas con enfermedad coronaria (EC) muestran hallazgos contradictorios. En el estudio Whitehall –en el que participaron empleados gubernamentales de sexo masculino de Londres–, 18 403 hombres de mediana edad que habían participado en un examen médico entre 1967 y 1970 fueron controlados durante 38 años. En los hombres que presentaban EC al inicio hubo pruebas de un riesgo ligeramente mayor de mortalidad por todas las causas y por EC, pero no por accidente cerebrovascular en los grupos con sobrepeso y obesidad en relación con los hombres de peso normal. Aunque estas tendencias fueron mucho más notables en los hombres sin EC al inicio del estudio, la diferencia según el estado basal de EC no alcanzó significación estadística en los niveles convencionales. Evitar la obesidad y el sobrepeso en la vida adulta tanto en hombres con EC como sin ella puede reducir el riesgo posterior de mortalidad total y mortalidad por cardiopatía coronaria.

The few reports on the association of obesity oroverweight with mortality in persons with existing coronary heart disease (CHD) reveal inconsistent findings.In the Whitehall study of London-based male government employees, 18 403 middle-age men were followed upfor up for a maximum of 38 years having participated in a medical examination between 1967 and 1970. In menwith baseline CHD, there was evidence of a modestelevated risk for mortality from all-causes and coronaryheart disease but not stroke in overweight and obesegroups relative to normal weight men. While these slopeswere markedly steeper in men who were CHD-free atstudy induction, the difference in the gradients accordingto baseline CHD status did not attain statistical significance at conventional levels. Avoidance of obesity and overweight in adult life in both men with and without CHD may reduce their later risk of total and coronary heart disease mortality.

Conocimientos, actitudes y prácticas acerca del SIDA entre estudiantes de escuelas secundarias de Managua / HIV/AIDS-related knowledge, attitudes, and practices among Managuan secondary school students

En 1990, se determinaron los conocimientos, actitudes y prácticas acerca del SIDA entre estudiantes del último año (5) de cuatro escuelas secundarias de Managua. Se empleó un cuestionario autoadministrado que fue completado por 451 estudiantes (155 varones y 296 mujeres) cuyo promedio fue 18 años. El 86 por ciento de los sujetos sabía que el SIDA era una enfermedad de transmisión sexual, pero fue mucho menor el porcentaje que conocía otras vías de transmisión y medidas preventivas eficaces. El empleo de condones fue mencionado como medida preventiva por 41 por ciento de los estudiantes, pero el porcentaje entre los varones fue significativamente mayor entre las mujeres (55 por ciento y 33 por ciento respectivamente, P=0,0001). Del total de los encuestados, 64 por ciento (90 por ciento de los varones y 50 por ciento de las mujeres) informaron que habían tenido relaciones sexuales. El 60 por ciento de los entrevistados estaba "muy preocupado" por el SIDA, pero solo el 23 por ciento consideraban que corrían riesgo de contraer la enfermedad. Entre los estudiantes sexualmente activos, 29 por ciento (38 por ciento de los varones y solo 7 por ciento de las mujeres), P=0,001), señalaron que se había modificado su comportamiento sexual a causa del SIDA. La notificación de una modificación de conducta se asoció mucho con la preocupación respecto a la enfermedad, pero fue débil la asociación entre la modificación del comportamiento sexual señalada y la percepción de un riesgo personal. En general, la encuesta indicó que los conocimientos acerca de la transmisión y la prevención del SIDA de los estudiantes de escuelas secundarias de Managua eran insuficientes, en especial entre las mujeres, lo que señala la necesidad de la educación sanitaria, que incluya intervenciones especificamente dirigidas a las jóvenes (AU)

Se publica en inglés en el Bull. PAHO. Vol. 27(4), 1993

HIV/AIDS-related knowledge, attitudes, and practices among Managuan secondary school students

In 1990, the AIDS-related knowledge, attitudes, and practices of fifth year (final year) students at four Managuan high schools were assessed. This was done by means of a self administered questionnaire completed by 451 students (155 males, 296 females) whose mean age was 18 years. Eighty-six percent of the subjects knew AIDS was transmitted sexually, but the percentage aware of other transmission pathways and effective preventive measures were much lower. Use of condoms was cited as a preventive measure by 41 percent of the students, but by significantly more male respondents than female respondents (55 percent of the males versus 33 percent of the females, p = 0.0001). Sixty-four percent of all the survey subjects (90 percent of the males, 50 percent of the females) reported experiencing sexual intercourse. Sixty percent of the respondents were "very much" worried about AIDS, but only 23 percent considered themselves at risk of contracting the disease. Among the sexually active students, 29 percent of the respondents (38 percent of the male but only 7 percent of the females, p = 0.001) indicated a change in sexual behavior because of AIDS. Reported behavior change was strongly associated with concern about AIDS, but the association between reported behavior change and perception of personal risk was weak. Overall, the survey indicated that knowledge about transmission and prevention of AIDS among Managuan high school students was insufficent, especially among females, indicating a need for health education including interventions specially targeted a female youth

This article will also be published in Spanish in the Bol. Oficina Sanit. Panam. Vol. 117(1):12-21, 1994