Search PubMed⌕ Search

Biomedical subjects

M de Onis

Publications and source records attributed to M de Onis.

At least 19 recordsLinked to original sources
PubMed2006

Construction of the World Health Organization child growth standards: selection of methods for attained growth curves.

The World Health Organization (WHO), in collaboration with a number of research institutions worldwide, is developing new child growth standards. As part of a broad consultative process for selecting the best statistical methods, WHO convened a group of statisticians and child growth experts to review available methods, develop a strategy for assessing their strengths and weaknesses, and discuss methodological issues likely to be faced in the process of constructing the new growth curves. To select the method(s) to be used, the group proposed a two-stage decision-making process. First, to select a few relevant methods based on a list of set criteria and, second, to compare the methods using available tests or other established procedures. The group reviewed 30 methods for attained growth curves. Using the pre-defined criteria, a few were selected combining five distributions and two smoothing techniques. Because the number of selected methods was considered too large to be fully tested, a preliminary study was recommended to evaluate goodness of fit of the five distributions. Methods based on distributions with poor performance will be eliminated and the remaining methods fully tested and compared.

Body Height↗
PubMed2005

Community-based supplementary feeding for promoting the growth of young children in developing countries.

BACKGROUND: Supplementary feeding is defined as the provision of extra food to poor children or families beyond the normal ration of their home diets. The impact of food supplementation on child growth merits careful evaluation in view of the reliance of many states and NGOs on this intervention to improve child health in developing countries. OBJECTIVES: To evaluate the effectiveness of community-based supplementary feeding for promoting the physical growth of pre-school children in developing countries. SEARCH STRATEGY: Searches of CENTRAL 2005 (Issue 2), MEDLINE 1966 to 2005, EMBASE 1980 to 2005, CINAHL 1982 to 2005, LILACS 1982 to 2005, Social Science Citation Index 1956 to 2005, and Dissertation Abstracts International (late 1960s to 2005) were conducted. SELECTION CRITERIA: Randomised controlled trials evaluating supplementary feeding in children aged 0-5 years old in developing countries. DATA COLLECTION AND ANALYSIS: Data were extracted and analysed independently by two authors. MAIN RESULTS: Four trials met the inclusion criteria for this review. No meta-analysis is currently appropriate due to the clinical heterogeneity among the included studies. We group these trials into two categories: a) studies without formally assessment of malnourishment at baseline and, b) studies involving children formally assessed as malnourished.a) A cluster RCT conducted in Indonesia in 1991(20 Day Care Centres, n = 113 children), found no benefit in weight-for-age and height-for-age z-scores of the intervention group compared to the control group after three months of intervention. A study in Guatemala included four villages as unit of analysis (exact sample sizes were not provided). The length of 3-yr-old children was based on a 'before-after comparison' by village size and type of supplement. According to this analysis, the difference in net change in the large villages was 2.55 cm and in the small villages was 2.35 cm. The mean of these differences is 2.45 +- 0.10 cm (mean +- SD).b) A study conducted in Jamaica (n = 65 children) reported a positive effect on length (cm) in the supplemented group compared to controls [WMD 1.3 (0.03 to 2.57)] after 12 months of intervention. A trial from Indonesia (n = 75 children) found no benefit in growth after 12 months of supplementation. AUTHORS' CONCLUSIONS: Based on the small number of available trials, no firm conclusions of the effectiveness of supplementary feeding to the growth of pre-school children could be drawn. Issues of research design such as blinding and sample size calculation need to be addressed in future studies.

Child↗
PubMed2004

The use of anthropometry in the prevention of childhood overweight and obesity.

OBJECTIVE: To review concepts and propose measures related to the use of anthropometry for early identification of excessive weight gain in children. METHODS: Review of results from national and international studies focusing on the assessment of childhood growth, and evaluation of the weight-for-height z-scores of individual children using the 1977 National Center for Health Statistics and the 2000 Centers for Disease Control and Prevention growth charts. RESULTS: At present, few countries (23%) use indicators based on weight and height measurements to classify child body weight status. Less than one-third of growth monitoring programmes assess the growth of children beyond 6 y of age. Growth charts based on descriptive samples of populations undergoing increasing trends of childhood overweight and obesity result in substantial underestimation of true rates of these conditions. CONCLUSION: Early recognition of excessive weight gain relative to linear growth should become standard clinical practice by the following: (a) the routine collection of height measurements to enable monitoring weight-for-height and body mass index (BMI); (b) the expansion of existing monitoring programmes to include the assessment of all children up to 18 y at least once a year; (c) the interpretation of weight-for-height and BMI indices based on prescriptive reference data; and (d) the early intervention after an increase in weight-for-height or BMI percentiles has been observed.

Anthropometry↗
PubMed2004

Factors associated with unconstrained growth among affluent Ghanaian children.

AIM: To identify socio-economic factors associated with unconstrained growth among children living in well-off neighbourhoods of Accra, Ghana. METHODS: A cross-sectional study involving the assessment of the anthropometric status of preschool children. Children (n = 309) between the ages of 12 and 23 mo who live in affluent communities in Accra, Ghana were recruited for the study. Weight, length and mid-upper arm circumference were taken. Information was collected on household demographics and socio-economic status, including parental education and household income. Associations between these variables and attained growth were analysed to establish cut-offs for screening children with unconstrained growth. RESULTS: The mean weight-for-age (WA), length-for-age (LA) and weight-for-length (WL) Z-scores of the sub-sample selected on the basis of high socio-economic criteria were -0.18, -0.40 and 0.16, respectively. Among these well-off children, 0% were underweight, 3.0% were stunted and 0% were wasted (Z-scores <-2). Factors associated with better anthropometric status were paternal education and household income. Two screening criteria combining the two variables were selected: polytechnic education and income > 1,000,000 cedis (435 US dollars) or university education and income > 200,000 cedis. CONCLUSIONS: The children experiencing unconstrained growth belonged to a sub-population of affluent households characterized by high paternal education and household income. This subpopulation was targeted for screening for the WHO Multicentre Growth Reference Study in Ghana.

Analysis of Variance↗
PubMed2004

Socioeconomic predictors of unconstrained child growth in Muscat, Oman.

We conducted a study to identify socioeconomic factors associated with unconstrained growth among preschoolers in Muscat, Oman. A sample of children born in 1995 and aged 28-43 months was drawn from the Child Health Registers of 2 health care centres. Sociodemographic data were collected by oral interview and maternal and child anthropometry measured. Regression analysis was used to identify socioeconomic indicators and cut-offs associated with unconstrained growth. Children from households with a monthly income > or = 800 Omani rials and mother's education > or = 4 years attained height-for-age levels comparable to the current international growth reference. By screening using this criterion, we could obtain a suitable sample for the World Health Organization Multicentre Growth Reference Study in Muscat.

Adult↗
PubMed2003

The Centers for Disease Control and Prevention 2000 growth charts and the growth of breastfed infants.

AIM: To evaluate the performance of the 2000 Centers for Disease Control and Prevention (CDC) growth charts in comparison with the National Center for Health Statistics/World Health Organization (NCHS/WHO) reference as a tool for assessing growth in healthy breastfed infants. METHODS: Weight and length measurements were obtained from a pooled longitudinal sample of 226 healthy breastfed infants. Weight-for-age (WA), length-for-age (LA) and weight-for-length (WL) z-scores based on the CDC and NCHS/WHO references were computed for each child. Age-specific mean z-scores and proportions below and above specific cut-off points were calculated. RESULTS: Breastfed infants grow more rapidly in the first 2 mo of life and less rapidly from 3 to 12 mo in relation to the CDC WA curves. Similarly, breastfed infants experience greater linear growth than the CDC median until age 4 mo. Thereafter, the mean LA z-score declines until month 9. Apart from a 1-mo difference in the time when linear growth begins to falter, the pattern of growth is remarkably similar when compared with the two references. The growth trajectories indicate that infants in the CDC reference are heavier and shorter than the NCHS/WHO reference population. Combining the two measurements as WL reveals that higher weight overrides lower length in the CDC versus the NCHS population, thus the estimated prevalence of wasting is higher by the CDC reference. CONCLUSION: As was the case when compared with the NCHS/WHO reference, there are notable differences in the growth trajectory of breastfed infants examined against the CDC reference. A reference based on healthy breastfed infants is required if the growth patterns of infants following international feeding recommendations are to be correctly assessed.

Body Height↗
PubMed2001

The National Center for Health Statistics reference and the growth of Indian adolescent boys.

BACKGROUND: Few studies describing the growth of adolescents exist because of the difficulties in interpreting anthropometric data in this age group. OBJECTIVE: We describe the growth of adolescent boys from West Bengal, India, and assess the adequacy of using the National Center for Health Statistics (NCHS) reference data. DESIGN: A cross-sectional anthropometric survey was conducted in 818 Bengali boys from middle-class families. Anthropometric measurements were taken on each subject's birthday (+/-3 d) by use of standard measuring techniques. The NCHS reference data on height and body mass index (BMI) were used to estimate age-specific prevalences of stunting, thinness, and overweight. BMI was also assessed by using British, Dutch, and French reference data. The biological parameters of the adolescent growth spurt were estimated by using the Preece-Baines growth model. RESULTS: With use of the 5th percentile of the NCHS reference data, the prevalence of thinness was approximately 5 times (50.5%) that of stunting (11.2%). The median curves of the 3 European references lay between the Indian and NCHS samples and also yielded high prevalences of thinness when applied to the study sample. The prevalence of being at risk of overweight was low (4.2%). Mean age at peak height velocity was 13.0 y and peak height velocity was 7.0 cm/y. CONCLUSIONS: The NCHS reference data seem inadequate for this sample. Consideration should be given to developing appropriate reference data based on healthy adolescent populations from different ethnic groups. Issues of maturation-related variation in assessing growth during adolescence should be given particular attention.

Adolescent↗
PubMed2001

Worldwide timing of growth faltering: implications for nutritional interventions.

OBJECTIVE: It is widely assumed that growth faltering starts at around 3 months of age, but there has been no systematic assessment of its timing using representative national datasets from a variety of countries. METHODOLOGY: The World Health Organization Global Database on Child Growth and Malnutrition includes the results of 39 nationally representative datasets from recent surveys in developing countries. Based on these data, mean z scores of weight for age, length/height for age, and weight for length/height were compared with the National Center for Health Statistics and Cambridge growth references, for children younger than 60 months. RESULTS: Mean weights start to falter at about 3 months of age and decline rapidly until about 12 months, with a markedly slower decline until about 18 to 19 months and a catch-up pattern after that. Growth faltering in weight for length/height is restricted to the first 15 months of life, followed by rapid improvement. For length/height for age, the global mean is surprisingly close to National Center for Health Statistics and Cambridge references at birth, but faltering starts immediately afterward, lasting well into the third year. CONCLUSIONS: These findings highlight the need for prenatal and early life interventions to prevent growth failure.

Anthropometry↗
PubMed2000

Prevalence and trends of overweight among preschool children in developing countries.

BACKGROUND: Obesity during childhood is a matter of growing concern. Several reports show increasing rates of obesity in developed countries, whereas the extent of the problem in developing countries remains unknown. OBJECTIVE: The aim of this study was to fill this gap by quantifying the prevalence and trends of overweight among preschool children in developing countries. DESIGN: One hundred sixty nationally representative cross-sectional surveys from 94 countries were analyzed in a standardized way to allow comparisons across countries and over time. Overweight was defined as a weight-for-height >2 SDs from the National Center for Health Statistics/World Health Organization international reference median. Prevalences of wasted children (< -2 SDs) are also presented to enable comparisons between both ends of the distribution. RESULTS: The global prevalence of overweight was 3.3%. Some countries and regions, however, had considerably higher rates, and overweight was shown to increase in 16 of 38 countries with trend data. Countries with the highest prevalences of overweight are located mainly in the Middle East, North Africa, and Latin America. Rates of wasting were generally higher than those of overweight; Africa and Asia had wasting rates 2.5-3.5 times higher than overweight rates. Countries with high wasting rates tended to have low overweight rates and vice versa. CONCLUSIONS: These estimates show that attention should be paid to monitoring levels and trends of overweight in children. This, however, should not be done at the expense of decreasing international commitments to alleviating undernutrition. The data presented confirm that undernutrition remains a major public health problem worldwide.

Africa, Northern↗
PubMed2000

Is malnutrition declining? An analysis of changes in levels of child malnutrition since 1980.

Nutritional status is the best global indicator of well-being in children. Although many surveys of children have been conducted since the 1970s, lack of comparability between them has made it difficult to monitor trends in child malnutrition. Cross-sectional data from 241 nationally representative surveys were analysed in a standard way to produce comparable results of low height-for-age (stunting). Multilevel modelling was applied to estimate regional and global trends from 1980 to 2005. The prevalence of stunting has fallen in developing countries from 47% in 1980 to 33% in 2000 (i.e. by 40 million), although progress has been uneven according to regions. Stunting has increased in Eastern Africa, but decreased in South-eastern Asia, South-central Asia and South America; Northern Africa and the Caribbean show modest improvement; and Western Africa and Central America present very little progress. Despite an overall decrease of stunting in developing countries, child malnutrition still remains a major public health problem in these countries. In some countries rates of stunting are rising, while in many others they remain disturbingly high. The data we have presented provide a baseline for assessing progress and help identify countries and regions in need of populationwide interventions. Approaches to lower child malnutrition should be based on successful nutrition programmes and policies.

Child↗
PubMed1998

Nutritional interventions for the prevention of maternal morbidity.

OBJECTIVE: To review the effectiveness of nutritional interventions to prevent maternal morbidity. METHODS: This is an overview of systematic reviews and individual randomized controlled trials (if no systematic review available) of nutritional interventions during pregnancy. For each nutrient intervention the main maternal morbidity data reported were extracted. These were pre-eclampsia/eclampsia, pregnancy-induced hypertension, hemorrhage, anemia, infection and obstructed labor. In addition, the trial settings, the number of trials and participants' characteristics were systematically extracted. RESULTS: The systematic reviews considered in this paper had only few trials that reported the selected maternal outcomes. Outcome measures are based sometimes on one trial only. Most of the interventions compared single micronutrient supplementation with placebo/no treatment and did not show significant benefits for the supplementation groups. Calcium supplementation in women at high risk of pregnancy hypertension reduced the incidence of high blood pressure (RR, 0.35; 95% CI, 0.21-0.57) and pre-eclampsia (RR, 0.22; 95% CI, 0.11-0.43). Similarly, in women with low dietary calcium intake, calcium supplementation resulted in a significant reduction in the incidence of high blood pressure (RR, 0.49; 95% CI, 0.38-0.62) and pre-eclampsia (RR, 0.32; CI, 0.21-0.49). In women at low risk of pregnancy hypertension or with adequate baseline calcium intake, the beneficial effects of calcium supplementation are small and unlikely to be of clinical significance. Both, iron and folate supplementation reduced the number of women with low pre-delivery hemoglobin. CONCLUSIONS: Routine calcium supplementation seems to be a promising intervention for pregnant women at risk of developing preeclampsia or have low calcium intake, but these findings need to be confirmed with a trial with adequate power in different settings. In populations with high incidence of nutritional anemia routine iron and folate supplementation should be recommended during ante-natal care. It is unclear at this stage if adding vitamin A to iron and folate supplementation in anemia prevalent areas provides further benefits. There is inadequate data on the benefits or harms of routine iron or folate supplementation in adequately nourished populations. With regard to other micronutrient supplementation, such as zinc, magnesium and fish oil, randomized controlled trials with sufficient power to detect clinically important differences in maternal and infant outcomes are needed.

Calcium↗
PubMed1998

The NCHS reference and the growth of breast- and bottle-fed infants.

The current international growth reference, the National Center for Health Statistics (NCHS) reference, is widely used to compare the nutritional status of populations and to assess the growth of individual children throughout the world. Recently, concerns were raised regarding the adequacy of this reference for assessing the growth of breast-fed infants. We used the NCHS reference to evaluate infant growth in one of the most developed areas of Brazil. Infants who were exclusively or predominantly breast-fed for the first 4-6 mo, and partially breast-fed thereafter, grew more rapidly than the NCHS reference in weight and length during the first 3 mo, but appeared to falter thereafter. The average growth of all infants, regardless of feeding pattern, was faster than the NCHS reference until approximately 6 mo, after which their growth became slower than that of the NCHS sample. To substantiate this finding, the NCHS growth curves were then compared with growth data of breast-fed infants in developed countries from pooled published studies, formula-fed North American and European infants and predominantly bottle-fed U.S. infants monitored by the Centers for Disease Control and Prevention (CDC) Pediatric Surveillance System. In all three cases, weights showed the same pattern as the Brazilian infants-higher than NCHS in the early months but an apparent decline thereafter. The pattern for length gain was similar but less marked. Breast-fed infants showed more pronounced declines than those who were predominantly bottle-fed. These findings suggest that the infancy portion of the NCHS reference does not adequately reflect the growth of either breast-fed or artificially fed infants. This probably results from characteristics of the original sample and from inadequate curve-fitting procedures. The development of an improved international growth reference that reflects the normal infant growth pattern is indicated.

Body Height↗
PubMed1998

Nutritional and antimicrobial interventions to prevent preterm birth: an overview of randomized controlled trials.

The study was conducted to assess the effectiveness of interventions for the prevention or treatment of nutritional and infectious disorders during pregnancy on preterm birth rates. Cochrane systematic reviews or any other more up-to-date systematic review of antimicrobial and nutritional interventions were sought. Electronic searches of the Cochrane Controlled Trials Register were carried out to identify any trials published since the most recent update of the systematic review. Also, authors of Cochrane systematic reviews, which have not been updated recently, were contacted regarding new information. Systematic reviews of nutritional and antimicrobial interventions during pregnancy, reporting preterm delivery rates (delivery before 37 weeks) and "prematurity" (including low birth weight) either as primary or secondary outcomes, were included. General interventions without a specific nutritional supplementation or antimicrobial component were not considered for inclusion. Interventions to stop labor or prolong pregnancy after a diagnosis of preterm labor were excluded. For each systematic review, data on preterm delivery rate by intervention group was obtained. The total number of trials in the review, number of trials reporting preterm birth as an outcome, number of participants and events have been systematically extracted. Eighteen systematic reviews (10 nutritional and 8 antimicrobial) were considered. Our results indicated that, overall, the treatment of asymptomatic bacteriuria reduces the incidence of preterm birth or low birth weight (< 2500 gm) (typical relative risk (RR): 0.67; 95 percent confidence interval (CI): 0.52-0.85). The protective effect of treating asymptomatic bacteriuria for preterm delivery persisted when only the three trials reporting preterm delivery (< 37 weeks) were included in the meta-analysis (typical RR: 0.53, 95 percent CI: 0.33-0.86). Routine iron supplementation prevents maternal anemia and one trial comparing routine versus selective iron supplementation showed a statistically nonsignificant reduction in preterm birth. Zinc, magnesium, and fish oil supplementations show promising results in reducing preterm birth, but the evidence is not strong. Calcium supplementation remains controversial, although there was a statistically significant reduction in preterm delivery in the subgroup of women at high risk of developing hypertension during pregnancy. Two trials with use of metronidazole (alone or with erythromycin) showed a reduction in preterm delivery in women who were at a high risk of preterm delivery and had bacterial vaginosis at screening. We have concluded that asymptomatic bacteriuria should be screened and treated in all settings that offer antenatal care. Single dose treatment seems to be as effective as longer (4-7 days) treatment, although this needs to be confirmed by a large, methodologically rigorous trial. There are a number of promising interventions such as calcium supplementation in women with low calcium intake, iron, zinc, magnesium, and fish oil supplementation, and treatment of bacterial vaginosis in women at high risk of preterm delivery that need additional research to determine a possible role for prevention of preterm delivery.

Anti-Infective Agents↗
PubMed1998

[Estimating the prevalence of height for age deficits based on the prevalence of weight for age deficits among Brazilian children].

INTRODUCTION: Anthropometry is frequently used for evaluating nutritional status of individuals and populations. In recent years, community surveys have been conducted by health professionals in various regions of Brazil with the objective of complementing the data obtained through nutritional surveillance programs. One important difficulty in conducting these assessments has been measuring height during visits to the homes of survey participants. METHODS: Thirty-eight anthropometric surveys of Brazilian children aged up to 5 years using the National Center for Health Statistics (NCHS) reference were identified. The percentage of children with a Z-score below standard deviations was used to define deficits of weight for age and height for age. RESULTS: Correlation between prevalences of height for age and weight for age deficits were examined. Due to the low prevalence of deficits in weight for height in all surveys, there was a strong correlation between weight for age and height for age at the population level. Approximately 90% of the height for age (H/A) variation was accounted for by that of weight for age (W/A). CONCLUSIONS: Using the equation, (Prevalence H/A) = 0.74 + 2.34 (Prevalence W/A) -0.03 (Prevalence W/A)2 it is possible to estimate the prevalence of height deficits on the basis of prevalence of weight deficits. These results suggest that anthropometric surveys as conducted in Brazil, in the context of health services, can be simplified by measuring weight only, instead of both weight and height.

Age Factors↗
PubMed1998

Levels and patterns of intrauterine growth retardation in developing countries.

The aim of this paper is to quantify the magnitude and describe the geographical distribution of intrauterine growth retardation (IUGR) in developing countries. We estimate that at least 13.7 million infants are born every year at term with low birth weight (LBW), representing 11% of all newborns in developing countries. This rate is approximately 6 times higher than in developed countries. LBW, defined as < 2500 g, affects 16.4% of all newborns, or about 20.5 million infants each year. IUGR defined as birth weight below the 10th percentile of the birth-weight-for-gestational-age reference curve, represents 23.8%, or approximately 30 million newborns per year. Overall, nearly 75% of all affected newborns are born in Asia--mainly in South-central Asia--20% in Africa, and about 5% in Latin America. Although some of these are healthy, small infants who merely represent the lower tail of a fetal growth distribution, in most developing countries a large proportion of newborns suffer from some degree of intrauterine growth retardation. These data demonstrate that many developing countries currently exceed the internationally recommended IUGR (> 20%) and LBW (> 15%) cut-off levels for triggering public health action, and that population-wide interventions aimed at preventing fetal growth retardation are urgently required.

Birth Weight↗
PubMed1998

Nutritional interventions to prevent intrauterine growth retardation: evidence from randomized controlled trials.

This report summarizes the evidence from systematic reviews of randomized controlled trials on the effectiveness of nutritional interventions aimed at reducing intrauterine growth retardation (IUGR). There were 12 interventions including protein-energy, vitamin, mineral, and fish oil supplementation, as well as the prevention and treatment of anemia and hypertensive disorders. A primary concern is the limited data supporting the effectiveness of recommended nutritional interventions during pregnancy, some of which are widely used even in women without nutritional deficiencies. Overall, with the exception of perhaps balanced protein/energy supplementation (typical odds ratio: 0.77; 95 per cent confidence interval: 0.58 to 1.01), no effective nutritional interventions for reducing the risk of IUGR have been demonstrated. Other interventions, such as zinc, folate and magnesium supplementation during gestation, merit further research which should be conducted among populations at risk of IUGR, using larger sample sizes, and addressing coexisting factors limiting fetal growth. Appropriate combinations of interventions should be a priority for evaluation as it is unlikely that a single factor will reduce a multicausal outcome like IUGR that is so dependent on socioeconomic disparities.

Dietary Proteins↗