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Biomedical subjects

M de Onis

Publications and source records attributed to M de Onis.

30 records · Page 2Linked to original sources

Socioeconomic and demographic factors are associated with worldwide patterns of stunting and wasting of children.

We estimated the variability among nations in the prevalence of stunting and wasting, evaluated which national factors are associated with stunting and wasting and examined the relationship of stunting with wasting. The World Health Organization Global Database on Child Growth, a comprehensive conceptual model and a database of national factors were used with variance components and regression analyses. There was substantial variability among nations and among provinces within nations. Most national variability for stunting (76%) and wasting (66%) was explained by national factors and geographic region. Higher energy availability, female literacy and gross product were the most important factors associated with lower prevalence of stunting. The association of health expenditures and stunting differed by region. Higher immunization rate and, for Asia only, energy availability were the most important factors associated with lower prevalence of wasting. Regional differences in the relationship between stunting and wasting were accounted for by national factors. Some factors associated with stunting and wasting differ at the national level. Child malnutrition within a household is greatly influenced by issues at national and provincial levels, and intervention should be considered at all three levels.

Child Nutritional Physiological Phenomena↗

Effectiveness of interventions to prevent or treat impaired fetal growth.

This is an overview of 126 randomized controlled trials (RCTs) evaluating 36 prenatal interventions to prevent or treat impaired fetal growth (IFG). Results are based on systematic reviews including the meta-analyses of these RCTs. Most of the prenatal interventions do not show any significant effects on short-term perinatal outcomes. There are, however, a few interventions likely to be beneficial: smoking cessation, antimalarial chemoprophylaxis in primigravidae, and balanced protein/energy supplementation. Others merit further research: zinc, folate, and magnesium supplementation during gestation. Appropriate combinations of interventions should be a priority for evaluation because it is unlikely that a single intervention will reduce a multicausal outcome like IFG that is so dependent on socioeconomic disparities. Of concern is the discrepancy between the importance given in the epidemiological and clinical literature to the problem of IFG and the methodological quality and sample size of the RCTs conducted for the evaluation of preventive or treatment modalities.

Fetal Growth Retardation↗

Time for a new growth reference.

The National Center for Health Statistics growth reference, recommended by the World Health Organization for international use since the late 1970s, has served many useful purposes. Among the most important are the provision of a single set of growth references for the assessment of the general nutritional status of populations of children in diverse settings, as an ancillary tool to screen children for health and nutrition disorders, and as a basis for educational materials that promote improved child care by families. However, because of serious drawbacks due to the origin and type of data used for their construction and the analytical methods applied in their derivation, the suitability of these curves for international purposes has been challenged recently.

Adolescent↗

The development of MUAC-for-age reference data recommended by a WHO Expert Committee.

Low mid-upper-arm circumference (MUAC), determined on the basis of a fixed cut-off value, has commonly been used as a proxy for low weight-for-height (wasting). The use of a fixed cut-off value was based on the observation that MUAC showed small age- and sex-specific differences. However, in 1993, a WHO Expert Committee concluded that age independence is not reflected in the true pattern of mid-upper arm growth, recommended the use of MUAC-for-age, and presented age- and sex-specific MUAC reference data developed with observations obtained from a representative sample of children in the USA aged 6-59 months. In this article, we explain the methodology for the development of these data, present age- and sex-specific growth curves and tables and discuss the applications and limitations of MUAC as a nutritional indicator. To develop the reference data, estimates were first obtained for the mean and standard deviation of MUAC for each month of age using 7-month segmental regression equations; a 5th-degree and a 3rd-degree polynomial in age was then used to describe the mean and standard deviation, respectively, of MUAC-for age. These curves show important age-specific differences, and significant sex-specific differences for boys and girls < 24 months of age. Correct interpretation of MUAC with regard to nutritional status requires the use of MUAC-for-age reference data such as those presented here.

Age Factors↗

The development of a MUAC-for-height reference, including a comparison to other nutritional status screening indicators.

Mid-upper-arm circumference (MUAC) based on a single cut-off value for all the children less than 5 years of age has been used for many years as an alternative nutritional status index for children during famines or refugee crises, and as an additional screening tool in nonemergencies. However, it has recently been questioned whether MUAC is age- and sex-independent. After reviewing the scientific evidence underlying the use and interpretation of MUAC, a WHO Expert Committee recommended a new MUAC-for-age reference for under-5-year-olds. In some settings, however, it is difficult to assess a child's age and in such circumstances MUAC-for-height may be a good alternative. The height-based QUAC stick is a simple means of adjusting MUAC cut-offs according to height, and the MUAC-for-height reference and the construction and use of the QUAC stick are described in this article. Described also is the use of the receiver operating characteristic (ROC) curve method to evaluate the performance of MUAC, MUAC-for-age, and MUAC-for-height in screening malnourished children.

Age Factors↗

A WHO Collaborative Study of Maternal Anthropometry and Pregnancy Outcomes.

OBJECTIVES: To evaluate to what degree anthropometric measurements are useful and efficient in predicting maternal and fetal outcomes in different country settings and to develop appropriate reference curves for maternal weight gain. METHODS: A meta-analysis of 25 data sets providing information on over 111,000 births worldwide. RESULTS: Attained weight indicators from pre-pregnancy (Pp) through 9 lunar months demonstrated high odds ratios (O.R.) for both low birth weight (LBW) and intra-uterine growth retardation (IUGR). The strongest effect size (O.R. = 4.0) was provided by attained weight at 7 lunar months for IUGR, when applied to women of below average pre-pregnancy weight. The study indicators showed only minor and inconsistent O.R. for preterm birth (PTB). The ability of study indicators to predict the three maternal outcomes was much weaker. Maternal height as a predictor of assisted delivery showed the highest positive O.R. (1.6), but did not meet the screening criteria. CONCLUSIONS: A single measurement of attained weight at 5 or 7 lunar months (16-20 or 24-28 weeks) is the most practical screening instrument for LBW and IUGR in most primary health care settings and provides warning of the need for intervention. The operational value of these findings should be demonstrated through their successful large-scale application in service settings.

Body Height↗

Anthropometric reference data for international use: recommendations from a World Health Organization Expert Committee.

The World Health Organization (WHO) convened an Expert Committee to reevaluate the use of anthropometry at different ages for assessing health, nutrition, and social wellbeing. The Committee's task included identifying reference data for anthropometric indexes when appropriate, and providing guidelines on how the data should be used. For fetal growth, the Committee recommended an existing sex-specific multiracial reference. In view of the significant technical drawbacks of the current National Center for Health Statistics (NCHS)/WHO reference and its inadequacy for assessing the growth of breast-fed infants, the Committee recommended the development of a new reference concerning weight and length/height for infants and children, which will be a complex and costly undertaking. Proper interpretation of midupper arm circumference for preschoolers requires age-specific reference data. To evaluate adolescent height-for-age, the Committee recommended the current NCHS/WHO reference. Use of the NCHS body mass index (BMI) data, with their upper percentile elevations and skewness, is undesirable for setting health goals; however, these data were provisionally recommended for defining obesity based on a combination of elevated BMI and high subcutaneous fat. The NCHS values were provisionally recommended as reference data for subscapular and triceps skinfold thicknesses. Guidelines were also provided for adjusting adolescent anthropometric comparisons for maturational status. Currently, there is no need for adult reference data for BMI; interpretation should be based on pragmatic BMI cutoffs. Finally, the Committee noted that few normative anthropometric data exist for the elderly, especially for those > 80 y of age. Proper definitions of health status, function, and biologic age remain to be developed for this group.

Adolescent↗

Nutritional status of preschool children in poor rural areas of China.

Described are the main findings of the first large-scale nutrition monitoring project carried out over a 4-year period in China. The nutritional status of nearly 10,000 preschool children in 18 comparatively poor rural areas in seven provinces was followed each year over the period 1986-89 in order to identify their major nutritional problems and improve their growth and development. Physical measurements were made and dietary surveys and biochemical tests were performed on a subsample of the children. The proportion of stunted and underweight children was far higher than the national average. Based on the possibilities offered by local circumstances, the prevalences of stunting and underweight were lowered and anaemia was greatly reduced. Along with the progress in nutrition monitoring, major efforts were made to train health workers, as well as to encourage increased production of green vegetables, poultry, and small livestock. The wealth of information collected and the experience gained may serve as a baseline record, the project currently being expanded to cover 100 counties throughout China.

Anemia↗

[Tobacco use in Spanish women].

Tobacco consumption among Spanish women has increased dramatically during the last 40 years, rapidly closing the gap between men and women in cigarette-smoking prevalence. This has already happened in the younger age group, in which the proportion of young women smoking is reaching that of young men. This pattern has been evidenced in several surveys carried out at the regional and country levels. The younger generation of Spanish women, together with its counterparts in France and the Netherlands, has one of the highest prevalences of tobacco consumption (49%) in the EEC, considerably higher than the corresponding average for the EEC as a whole (39%). In Spain, a female smoker tends to be young, educated and in the upper-income level. Applying the standard attributable-risk approach, it has been estimated that in 1986 approximately 8,000 female deaths resulted from cigarette smoking in Spain, representing about 6% of all female deaths, with the majority being due to diseases of the circulatory system. Between 1980 and 1987, female hospital admissions due to lung cancer increased more than a 100%. In forthcoming years in Spain, one can expect a dramatic increase in the absolute number of female deaths caused by smoking-related diseases, due to the increase in smokers among the young generations, who will eventually attain the ages at which smoking-related disease appear. This younger age group is comparable to male smokers, and as they move into their 60s and 70s, their risk of lung cancer and ischaemic heart disease will most likely come to resemble the risks for men smoking the same numbers of cigarettes today.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

The differential neonatal morbidity of the intrauterine growth retardation syndrome.

This is a prospective study of differential morbidity among subgroups of intrauterine growth retardation. Cases of intrauterine growth retardation (N = 3450) (greater than or equal to 37 weeks, less than 10th percentile birth weight for gestational age) were classified by their ponderal index (weight/length3) in four subgroups using the 10th, 25th, and 90th percentiles of the Lubchenco's ponderal index-gestational age distribution. There were 432 cases (12.5%) with low ponderal index or disproportionate intrauterine growth retardation, 936 (27.1%) with intermediate ponderal index, 2030 (58.8%) with adequate ponderal index or proportionate intrauterine growth retardation, and 52 (1.5%) with high ponderal index. The low ponderal index group or disproportionate intrauterine growth retardation group had a statistically significant higher risk (between 1.6 and 12.5 times) for low 1- and 5-minute Apgar scores, aspiration syndrome, hypoglycemia, and perinatal asphyxia than the adequate ponderal index group. The low ponderal index group also had an increased risk (relative risk = 2.0 [95% confidence interval, 1.0 to 3.8]) for hospital stay of more than 1 week. These differences persist after a stratified analysis by birth weight and in a multiple logistic regression analysis. Similarly, higher neonatal morbidity is observed among infants with normal birth weights but with low ponderal index. These data provide further evidence of the heterogeneity of the intrauterine growth retardation syndrome and of the independent effect of body disproportion on neonatal morbidity, even among infants with normal birth weights. Because there are significant clinical implications attributed to the low ponderal index group, this subgroup should be identified as early as possible.

Birth Weight↗

The effect of maternal work on fetal growth and duration of pregnancy: a prospective study.

The effect on birth outcome of work requiring different degrees of physical exertion was examined among 15,786 pregnant women who were followed through the Guatemalan Social Security Institute's hospital. Work inside and outside the home was ascertained through a questionnaire administered to each women before delivery. Odds ratios were adjusted for household income, maternal height and age, and birthweight of previous infant. Women with three or more children and no household help were at increased risk for small-for-gestational-age (SGA) births compared with women with family (odds ratio (OR) 1.79; 95% confidence interval (CI) 1.31, 2.47) or hired help (OR 2.0; 95% CI 1.16 to 3.33). Compared with office work, manual work increased the risk for an SGA (OR 1.32; 95% CI 1.12 to 1.56) and SGA/preterm birth (OR 2.56; 95% CI 1.10 to 5.96). Work in a standing compared with sitting position significantly increased the risk for a preterm birth (OR 1.56; 95% CI 1.04 to 2.60). There was a significant positive trend in frequency of SGA and SGA/preterm birth with an increase in the physical demands at work, as measured by an activity score. These data suggest that interventions to reduce physical exertion among pregnant women could improve birth outcome.

Adult↗