Cristina Padez

Prevalence and risk factors for overweight and obesity in Portuguese children.

Aim: To identify risk factors for overweight and obesity in Portuguese children.

Maternal weigh gain during pregnancy and overweight in Portuguese children

Objective:The objective of our study was to assess the association between maternal weight gain during pregnancy and childhood overweight.Design:This study was a cross-sectional analysis.Setting:The data were derived from a community-based survey of children from primary schools of Portugal.Subjects:The study was performed in a sample of 6-12-year-old Portuguese school children (2445 girls and 2400 boys; age was 8.5±0.91 years).Measurements:Height and weight were measured according to international standards, and body mass index (BMI) was calculated. The definition of overweight was based on average centiles according to the International Obesity Task Force cutoffs. Childrens parents completed a self-administered questionnaire, which provided information on general family background characteristics, maternal weight gain during pregnancy and childrens physical activity. The response rate was 70.6%. Childrens dietary intake was measured using a 24-h dietary recall. Logistic regression models were fitted to estimate the magnitude of the association between maternal weight gain during pregnancy and overweight in their children, adjusting for confounders (gender, age, birthweight, order of birth, breastfeeding, smoking during pregnancy, physical activity, parental BMI, parental education, calcium to protein ratio and energy intake).Results:The prevalence of overweight (including obesity) was 29% in boys and 33% in girls. The odds favouring overweight (including obesity) increased significantly for those women who gained ⩾16 kg during pregnancy, compared to those with <9 kg , even after adjustment for confounders (crude odds ratio (OR)=1.53, confidence interval (CI) 95% 1.27–1.84, P-trend <0.001; Adjusted OR=1.27, CI 95% 1.01–1.61, P-trend=0.038).Conclusion:Large maternal weight gain during pregnancy (⩾16 kg) was significantly associated with higher risk of overweight in Portuguese children.

Secular trend in stature in the Portuguese population (1904-2000)

The records of height of 995 101 18-year-old Portuguese males were analysed as well as the relation between localities of the subjects residence (districts) and final height. The sample includes all the Portuguese 18-year-old males born between 1966 and 1982 and examined between 1985 and 2000, in the north, centre and south of Portugal, representing all the social strata. Statistically significant differences ( p h 0.001) among the districts were found: males from Lisboa (172.79 cm) and Braga (172.67 cm), the most developed districts, are the tallest, and those from Madeira (170.67 cm), Castelo Branco, Leiria and Coimbra (171.31 cm) are the shortest. Comparing to published data from 1904, a positive secular trend in height was found. The average increase was 8.93 cm, which yields a rate of 0.99 cm per decade. This positive trend must be related to the general improvement in the populations standard living conditions that took place in Portugal mainly after the 1960s and 1970s, especially in terms of nutrition and the health system. However, taking into account the differences that still exist in mean height values between the districts, these results suggest that there are still great social inequalities in Portugal and the secular trend in height will continue for the Portuguese population in future decades.

Parent and Child Screen-Viewing Time and Home Media Environment

BACKGROUND Screen-viewing time has been associated with adverse health outcomes. Data on the predictors of youth screen-viewing time is predominately from older children in North America. Parental and home media environment factors that are associated with screen-viewing time could be targeted in interventions. PURPOSE Examine if parental screen-viewing time and electronic media (access to game equipment, TVs, PCs, and laptops) environment factors were associated with Portuguese childrens screen-viewing time and if associations differed by child age (<7 vs ≥7 years); gender; or type of screen viewing. METHODS Data are reported for 2965 families with children aged 3-10 years. Data were collected in 2009-2010 and analyzed in 2011. Outcomes were child spending ≥2 hours watching TV and ≥1 hour per day playing with combined other media. Exposures were mothers and fathers watching ≥2 hours of TV and electronic media variables. RESULTS Parental TV-viewing time was strongly associated with child weekday and weekend TV-viewing time across all four gender and age subgroups. Maternal TV-viewing time was a stronger predictor of child TV-viewing time than paternal TV-viewing time. There was very limited evidence that parental TV-viewing time was associated with combined other media time among boys or girls. Access to electronic game equipment increased the likelihood that children spent >1 hour using combined other media on weekdays and weekend days. CONCLUSIONS Parental TV-viewing time was associated with Portuguese childrens TV-viewing time. The numbers of TVs in the household and electronic games equipment access were also associated with TV- and combined other media-viewing/usage time.

Dietary calcium and body mass index in Portuguese children

Objective:The objective of our study was to assess nutritional intake in school children (7–9-y-old) and relate calcium intake to body mass index (BMI).Design:This study was a cross-sectional analysis.Setting:The data were derived from a community-based survey of children from primary schools of Portugal.Subjects:In all, 3044 Portuguese children (1503 girls and 1541 boys) from a community-based sample of 7–9-y-olds.Methods:Height and weight were measured according to international standards, and BMI was calculated. Childrens parents completed a self-administered questionnaire that provided information on general family background characteristics and childrens physical activity. Childrens dietary intake was measured using a 24-h dietary recall. Calcium intake was expressed as the calcium-to-protein ratio, and regression analysis was used to estimate the association between calcium intake and BMI, adjusting for energy intake and confounders.Results:The prevalence of children with calcium intake below the Dietary Reference Intake was higher in girls (36.4 vs 33.0%, P=0.053). Calcium-to-protein ratio predicts BMI only in girls (β=−0.052, P=0.002), even after adjusting for age, energy intake, parental education, and physical activity.Conclusion:We found an inverse relationship between calcium intake and BMI only in girls. These data reinforce the need for controlled trials to assess the effects of dietary calcium on body mass in each gender.Sponsorship:Fundação Ciência e Tecnologia POCTI/ESP/43238/2001.

Age at menarche of schoolgirls in Maputo, Mozambique

Age at menarche was analysed in 753 Mozambican schoolgirls taking part in across-sectional anthropometric study in Maputo, Mozambique, in 2000. The probit analysis of the status quo data yielded an median age at menarche of 13.20 +/- 1.18 years. The retrospective method was applied only to recall data of the 396 post-menarcheal girls and it yielded an average of 13.91 +/- 1.29 years. Mean age at menarche in girls living in the urban centre of Maputo was 13.35 and 12.96 years, for recall age and probit analysis, respectively, and 14.51 and 13.68 years for girls living in the slums surrounding the centre. The differences in age at menarche, calculated by recall method, between girls from central Maputo and girls from the slums were statistically significant (p = 0.000). Parents educational level also revealed a significant effect on age at menarche. Girls whose parents had a lower educational level showed a later age at menarche. For the size of the family, girls who were later borne had a higher age at menarche. In the 1960s, the age at menarche was 13.55 and 13.83 years in urban and rural girls, respectively. In this study, we found a lack of decrease in the mean age at menarche (13.9 years), which could be due to the poor living conditions in Mozambique between 1960 and 2000 as a result of the civil war from 1976 to 1990. Despite the economic growth of the country in the last decade, Mozambique is still in the group of the poorest countries in the world; in spite of this fact, the mean menarcheal age in these girls are amongst the lowest values presented for African countries.

Socio-demographic and behavioral risk factors associated with the high prevalence of overweight and obesity in Portuguese children.

Childhood obesity is a public health concern in Portugal. Socio‐demographic and behavioral factors are highly associated with obesity but are not clearly understood. This article aims to update the prevalence of overweight and obesity in Portuguese children and to explore the influence and risks of socio‐demographic factors and behavioral factors.

Type-specific screen time associations with cardiovascular risk markers in children

BACKGROUND There is evidence that TV time may have stronger associations with cardiovascular risk markers than other types of screen time, but most studies focus on TV, or total screen time. PURPOSE To examine associations between types of screen time and cardiovascular risk markers in school-age children. METHODS Cross-sectional study of 2515 school children in Portugal (aged 2-12 years, data collected in 2009 and 2010). Three types of screen time (TV, electronic games, and PC time) were collected through a questionnaire, and data on three cardiovascular risk markers (resting heart rate; diastolic blood pressure [DBP]; and systolic blood pressure [SBP]) were collected by a trained fieldworker. Complex-samples generalized linear models were run for each combination of screen time predictor and cardiovascular risk outcome, and a clustered cardiovascular risk score, adjusting for potential confounders (including physical activity). Analyses were conducted in 2011 and 2012. RESULTS TV viewing, but not PC or electronic games time, was associated positively with clustered cardiovascular risk score, DBP, and SBP after adjustment for all covariates. Watching TV for >2 hours/day (compared to <1 hour/day) was associated with higher DBP (coefficient, logged and back-transformed 0.02, 95% CI=0.00, 0.04, linear trend p=0.003); SBP (logged and back-transformed 0.02, 95% CI= -0.01, 0.05, p=0.009), and clustered cardiovascular risk score (0.13, 95% CI=0.02, 0.24, p<0.001). CONCLUSIONS TV viewing, but no other type of screen time, was associated positively with cardiovascular risk markers independently of physical activity. Studies using a single marker of screen time or sedentary behavior may conceal screen time type-specific associations.

Associations between indicators of screen time and adiposity indices in Portuguese children.

OBJECTIVES To examine associations between three types of screen time (TV, electronic games (EG), and personal computer (PC)) and two proxies of adiposity (body mass index (BMI) and sum of skinfolds) in children. DESIGN The sample comprised 17,509 children aged 2-13 years who participated in the 2009/10 Portuguese Prevalence Study of Obesity in Childhood. METHODS Complex samples generalised linear models, using school as a cluster variable were ran separately for each combination of ST predictor and adiposity-related outcome, adjusting for covariates including age, sex, physical activity, diet, and parental factors. Missing values in predictors and covariates were imputed. RESULTS Watching TV for >2h/day compared to <1h/day was associated with higher age- and sex-specific BMI standard deviation score (coefficient: 0.06, 95% CI: 0.01 to 0.12, linear trend p=0.008) and sum of skinfolds (logged and back transformed 0.04, 0.02 to 0.07, p=<0.001). We also found weak evidence for an inverse association between PC and BMI. CONCLUSIONS Associations between ST and adiposity differ by both type of ST and type of adiposity marker. Only TV viewing was consistently associated with adiposity. Studies using a single adiposity marker looking at total screen time or total sedentary behaviour time may miss or confound type-specific associations.

Height and Relative Leg Length as Indicators of the Quality of the Environment Among Mozambican Juveniles and Adolescents

The growth status of Mozambique adolescents was assessed to test the hypothesis that relative leg length is a more sensitive indicator of the quality of the environment than the total height. The sample comprised 690 boys and 727 girls, aged between 9 and 17 years, from Maputo. It is divided between those living in the Centre of Maputo and those living in the slums on the periphery of the city. Height, weight, and sitting height were measured and the sitting height ratio was calculated. The hypothesis that relative leg length is more sensitive than total stature as an indicator of environmental quality is not uniformly confirmed. Overall, mean stature is greater for the centre group than the slum group, but relative leg length as measured by the sitting height ratio does not differ. Compared with African‐American references (NHANES II), all centre girls, 9‐ to 14‐year‐old slum girls, all slum boys, and the oldest centre boys show relatively shorter legs. These findings show that within the Mozambique sample, relative leg length is not sensitive enough to distinguish the quality of the living environment. Mozambique was a colony of Portugal until 1975. Civil unrest and warfare characterized the late Colonial period and the postindependence period until a peace settlement was concluded in 1992. It is possible that all socioeconomic status groups within the country suffered sufficiently to reduce relative leg length compared with the better‐off African‐American reference sample. Possible genetic influences on relative leg length are also discussed. Am. J. Hum. Biol. 2009.