Clinical and biochemical characteristics associated with anthropometric nutritional categories.

Clinical nutrition status as well as selected biochemical characteristics, levels of parasitic infection and aspects of family and health history were assessed in rural EI Salvadoran children categorized as severely malnourished by anthropometric measurements. The anthropometric categories used were based on weight-for-age, weight-for-height, height-for-age, and simple mid-upper-arm circumference. Results indicated that 16 of 17 children with less than 80% of expected weight-for-height ("wasted") and all 17 children with arm circumference below 12.5 cm had clinically evident malnutrition. Children with less than 82.5% of expected height-for-age ("stunted") were more frequently anemic than controls and had a higher intestinal parasite burden, but only 3 of 23 were malnourished clinically. Sixteen of 22 children with severe weight-for-age deficit (Gomez grade III) were judged clinically malnourished, but the remaining six were underweight primarily because of short stature and did not appear malnourished clinically. The results illustrated the inability of weight-for-age classification to distinguish between acute and chronic malnutrition. The interrelationships between weight-for-height, height-for-age, and weight-for-age classification are illustrated graphically as a guide to the interpretation of these results.

Sensitivity and specificity of arm circumference indicators in identifying malnourished children.

Arm circumference indicators of nutritional status such as simple arm circumference, arm circumference-for-age and arm circumference-for-height have advantages for field use because of their simplicity and low cost. However, these indicators need to be evaluated in terms of their ability to identify children who are manourished by more accepted criteria such as weight-for-age and weight-for-height. This study used sensitivity-specificity analysis to evaluate arm circumference indicators in 3838 children 1 to 4 years of age in a rural area of El Salvador. It was found that simple arm circumference gave sensitivity-specificity results similar to arm circumference-for-age and generally better than arm circumference-for-height in identifying children with low weight-for-age. The three arm circumference indicators gave similar sensitivity-specificity results in identifying children with low weight-for-height. Linear correlations of the arm circumference indicators with weight-for-age and weight-for-height gave results which correspond to the results of sensitivity-specificity analysis, but the information obtained from correlations to was less useful in evaluating the adequacy of the individual arm circumference indicators for screening purposes. Sensitivity-specificity analysis is proposed as useful method for evaluating indicators for use in nutritional surveys and for screening for malnutrition.

Interpretation of Z-score anthropometric indicators derived from the international growth reference.

The WHO international growth reference was reviewed to identify characteristics that might affect the interpretation of anthropometric indicators derived from it. Discontinuities were found at the junction point of the two distinct data sets from which the reference curves are derived. Also, the Z-score derived percentile curves for weight-for-age and weight-for-height did not join due to differences in the variances of the two portions of the reference. Empirically an examination of data from international nutrition surveys revealed an artifactual drop in the prevalence of low height-for-age, low weight-for-height, and high weight-for-height at age 2 y, which is due substantially to these discontinuities rather than to intrinsic changes in nutritional status with age. Strategies are discussed for the interpretation of anthropometric indicators in light of these characteristics of the international reference.

Findings relating to goiter and iodine in the Ten-State Nutrition Survey.

Examinations for thyroid size were carried out on 35,999 individuals in the Ten-State Nutrition Survey. Overall goiter prevalence was found to be 3.1 per cent with the higher prevalence of goiter among adolescents and adults. Females of all ages had a higher prevalence of goiter than did males. No consistent regional pattern of the occurrence of goiter was observed. Urinary iodine excretion values used to estimate iodine intake indicated very few persons with excretion values suggesting iodine deficiency. No association between goiter and low iodine excretion was observed. On the contrary, a higher prevalence of goiter was found among persons excreting high levels of iodine. There is no indication from this study of widespread, iodine-deficiency goiter.

Arm muscle indicators and creatinine excretion in children.

The ability of anthropometric measurements, including arm muscle area calculated from arm circumference and triceps skinfold thickness, to estimate creatinine excretion as an index of muscle mass was tested in 14 fully active children, 2 to 6 yr of age in a residential care facility. The children were placed on a meat and fish-free diet for 36 to 48 h before the determination of mean creatinine excretion during three 24-h urinary collections. Results indicated highly significant correlations between mean creatinine excretion and height (r = 0.71), weight (r = 0.69), and arm circumference (r = 0.63). However, arm muscle area had the highest correlation with creatinine excretion (r = 0.86) of any anthropometric variable used. Step-wise multiple-regression analysis indicated that including height or weight with arm muscle area did not significantly improve the estimation of creatinine excretion, but that weight for height added significantly to improve the estimation of creatinine excretion, but that arm muscle area can provide a useful index of body muscle as reflected in urinary creatinine excretion in young children.

Seasonal differences in breast-feeding in rural Egypt.

Two surveys in Upper and Lower rural Egypt allowed an analysis of the seasonality of infant feeding. The first, including 937 children, was conducted during the relatively cool season of low diarrhea incidence in January-April 1978; the second, including 976 children, took place during the hot season of high diarrhea incidence in August-September 1980. Of infants 6-11 mo old, the proportion exclusively breast-feeding was greater in the hot-season survey (40% vs 16% in Lower Egypt, p less than 0.01; 36% vs 22% in Upper Egypt, p less than 0.01). Of children 12-17 mo old, a higher proportion were completely weaned during the hot season in Lower Egypt only (28% vs 14%, p less than 0.01). This difference was explained by an increase in pregnancy rates during the hot season resulting in less breast-feeding. Seasonal variation must be considered in the interpretation of infant-feeding surveys.

PIP: 2 surveys in Upper and Lower rural Egypt allowed an analysis of the seasonality of infant feeding. The 1st, including 937 children, was conducted during the relatively cool season of low diarrhea incidence in January-April 1978; the 2nd, including 976 children, took place during the hot season of high diarrhea in August-September 1980. On infants 6-11 mo old, the proportion exclusively breastfeeding was greater in the hot-season survey (40% vs. 16% in Lower Egypt, p0.01; 36% vs 22% in Upper Egypt, p0.01). Of children 12-17 months old, a higher proportion were completely weaned during the hot season in Lower Egypt only (28% vs 14%, p0.01). This difference was explained by an increase in pregnancy rates during the hot season resulting in less breastfeeding. Seasonal variation must be considered in the interpretation of infant-feeding surveys.

Overweight adults in the United States: the behavioral risk factor surveys.

Using data on 19,405 adults from telephone interviews across the US, 1981-1983, we examined the sociodemographic characteristics, health-risk behaviors, body image, and dieting of overweight adults classified by the 1959 Metropolitan Life Insurance tables for weight and height. By self-report, 23% were overweight vs 29% in 1960-62. This modest decline in overweight remained after age-adjusting the 1981-1983 rate to the 1960 population. In 1981-1983, more blacks and Hispanics than whites were overweight [rate ratio (RR) = 1.43]. After adjustment for age and education, more over- than average-weight adults had uncontrolled hypertension, were binge drinking, and had a sedentary lifestyle. Among overweight men and women, 72% and 52%, respectively, were not dieting. Overweight adults acknowledging they were overweight were dieting more often than those without this perception (RR = 1.53). Results are discussed in light of research documenting weight gain and overweight as independent risk factors for cardiovascular disease incidence and mortality.

Development of normalized curves for the international growth reference: historical and technical considerations.

The World Health Organization recommended in 1978 that the National Center for Health Statistics/Centers for Disease Control growth reference curves be used as an international growth reference. To permit the expression of growth in terms of standard deviations, CDC developed growth curves from the observed data that approximate normal distributions. Because of significant skewness, standard deviations for weight-for-age and weight-for-height were calculated separately for distributions below and above the median. Standard deviations below the median were calculated from the 5th, 10th, 25th, and 50th observed percentiles while those above the median were based on the 50th, 75th, 90th, and 95th observed percentiles. Height-for-age distributions did not show significant skewness, thus, the standard deviations were calculated based on all six of the above observed percentiles. The normalized reference curves provide a highly useful data base that permits the standardized comparison of anthropometric data from different populations.

PIP: The World Health Organization recommended in 1978 that the National Center for Health Statistics/Centers for Disease Control (CDC) growth reference curves be used as an international growth reference. To permit the expression of growth in terms of standard deviations, CDC developed growth curves from the observed data that approximate normal distributions. Because of significant skewness, standard deviations for weight-for-age and weight-for-height were calculated separately for distributions below and above the median. Standard deviations below the median were calculated from the 5th, 10th, 25th, and 50th observed percentiles while those above the median were based on the 50th, 75th, 90th, and 95th observed percentiles. Height-for-age distributions did not show significant skewness, thus, th standard deviations were calculated based on all 6 of the above observed percentiles. The normalized reference curves provide a highly useful data base that permits the standardized comparison of anthropometric data from different populations.

Body composition of Peruvian children with short stature and high weight-for-height. II. Implications for the interpretation for weight-for-height as an indicator of nutritional status.

In some child populations, low height-for-age, suggesting chronic undernutrition, may paradoxically be accompanied by relatively high weight-for-height, suggesting obesity. This growth pattern was investigated with anthropometric assessment and body composition studies using H2(18)O stable isotope dilution in 139 preschool-age Peruvian children. Results suggested low height-for-age (15th percentile National Center for Health Statistics [NCHS]) and high weight-for-height (60th percentile NCHS). Skinfold thicknesses were lower whereas arm muscle areas were more similar to NCHS reference values. Total body water (as percent body weight) was greater than reference values, consistent with lower body fat. Differences in body proportions did not account adequately for the high weight-for-height. The data suggest that the high weight-for-height in these children is not obesity but is associated with lower body fat and greater lean tissue or lean tissue hydration that may reflect dietary, environmental, or genetic influences. Weight-for-height cutoffs for wasting or obesity may require different interpretations for different populations.

Ethnic group differences in nutritional status of young children from low-income areas of an urban county.

A nutrition assessment survey was undertaken among 566 preschool children from randomly selected low income households located within an urban county. The purpose of the survey was to determine the prevalence of selected nutrition problems and to identify relationships among ethnic and economic variables and nutritional status. Underweight was identified in 1.8%, overweight in 15.4%, and short stature in 13.1% of children. Southeast Asian children had a higher prevalence of short stature than the other ethnic groups. Low hemoglobin values were identified in 4.3%, low hematocrit in 6.9%, and elevated erythrocyte protoporphyrin in 6.0% of children. The prevalence of elevated EP was significantly higher among Southeast Asian children than non-Southeast Asians and likely was due to iron deficiency. Results of the survey suggest that Southeast Asian children constitute the group at highest nutritional risk in the low income areas surveyed.

Evaluation of reactions to food additives: the aspartame experience.

Despite the widespread use of chemical food additives, few criteria exist to evaluate consumer reports of adverse reactions. We analyzed 231 consumer complaints associated with the food additive aspartame. We developed a methodologic approach to evaluate all complaints by adapting general criteria used to investigate adverse reactions to medications. Complaints were ranked according to the effects of cessation and rechallenge. Using this method, we found no clear symptom complex that suggests a widespread public health hazard associated with aspartame use; however, we identified some case reports in which the symptoms may be attributable to aspartame in commonly-consumed amounts. The systematic application of pre-defined review criteria, such as those described here, to monitor consumer complaints related to food additives will help identify products that warrant more focused clinical studies.

Body composition of Peruvian children with short stature and high weight-for-height. I. Total body-water measurements and their prediction from anthropometric values.

Total body water (TBW) was measured by 18O dilution in 139 undernourished, preschool Peruvian children with high weight-for-height. Values for TBW as a percent of body weight were relatively high, averaging 67.4 +/- 6.4%. Depending upon the method of calculation, mean values for the sample population for percent fat ranged from 9.4-18.5%. Regression of TBW on lean body mass suggested that hydration of the fat-free body was higher than for normally nourished children of comparable age. Thus, the increased weight-for-height in these children did not result from increased fat tissue, but from increased hydration of the fat-free body. TBW was most highly correlated with height and weight, both with r = 0.95. Equations predicting TBW from either height or weight were significantly different from those developed by other investigators to predict TBW for normal, well-nourished American children.

Childhood obesity: future directions and research priorities.

The threat of obesity is greater than ever for US children and adolescents. All indications are that the current generation of children will grow into the most obese generation of adults in US history. Furthermore, there is every expectation that the next generation of children is likely to be fatter and less fit than the current generation. Despite the recognition of the severe health and psychosocial damage done by childhood obesity, it remains low on the public agenda of important issues facing policy makers. Perhaps this is because the most serious health effects of obesity in today's children will not be seen for several decades. Action must be taken now to stem the epidemic of childhood obesity. This action will require a prioritization of research into the etiology, treatment, and prevention of childhood obesity. It is unlikely that sufficient resources for such research will be available from public and private sources until the issue of childhood obesity is moved higher on the public agenda.

Iodine and goiter in children.

Goiter examination was performed on 7,785 children aged 9 to 16 years in four areas of the United States--Michigan, Kentucky, Texas, and Georgia. Urinary iodine and creatinine, thyroxine, protein-bound iodine, and plasma inorganic iodide determinations were made on 377 matched pairs of goitrous and nongoitrous control children. The overall prevalence of goiter was 6.8%. Most children with goiter had palpably but not visibly enlarged thyroids and showed no evidence of clinical or biochemical thyroid abnormalitymmean urinary iodine excretion was 452 mug/gm of creatinine, many times the 50 mug/gm of creatinine level used to define deficiency. Children with goiter and areas with high goiter prevalence tended to have higher rather than lower iodine excretion. These findings are consistent with other data indicating high iodine intakes in the United States and suggest that goiter in American children cannot be assumed to be related to iodine deficiencymthe possible role of high iodine intake in the causation of goiter is discussed.

Birth weight and childhood growth.

Most previous studies of the relationship between birth weight and childhood growth have concentrated on the growth of low birth weight infants. To examine this relationship throughout the full range of birth weights, growth data for children less than 5 years of age from the Tennessee Special Supplemental Food Program for Women, Infants, and Children linked to birth certificate records for 1975 to 1985 were used. Growth status was compared for 500-g birth weight categories from 1,000 g to 4,999 g using mean Z scores and the percentage of children more than 2 SD above or less than 2 SD below the median for height for age, weight for age, and weight for height. Infants with lower birth weights were likely to remain shorter and lighter throughout childhood, especially those who were intrauterine growth retarded rather than premature. Conversely, those infants with higher birth weights were likely to remain taller and heavier and to have a higher risk of obesity. Birth weight is a strong predictor of weight and height in early childhood, not only for low birth weight children but also for those of normal and high birth weight.

Development of a research child growth reference and its comparison with the current international growth reference.

OBJECTIVE: To better characterize childhood growth and further assess potential limitations of the current National Center for Health Statistics and World Health Organization international growth reference. DESIGN: The LMS method was used for curve fitting to summarize the changes in height and weight distributions by 3 curves representing the skewness (L), median (M), and coefficient of variation (S). A series of polynomial regression procedures was applied to smooth the L, M, and S curves. SETTING: Subset data from 18 states contributing clinic data to the Centers for Disease Control and Prevention Pediatric Nutrition Surveillance System were used for this research reference. METHODS: We chose only those clinics in which the height and weight distributions of children closely matched with those of the first and second National Health and Nutrition Examination Surveys. RESULTS: Unlike the current international growth reference, the new reference has no disjunction at 24 months of age because it is based on a single data source for children aged 0 to 59 months. The reference also better characterizes the growth for infants than the current international reference, a fact we demonstrated with data from the National Health and Nutrition Examination Surveys, Pediatric Nutrition Surveillance System 1995, and the Davis Area Research on Lactation, Infant Nutrition, and Growth studies. CONCLUSIONS: The current National Center for Health Statistics and World Health Organization international growth reference needs to be updated. The methods used in this study will be useful to evaluate other data sets and to evaluate future modifications of growth references.

Seasonal changes in malnutrition and diarrheal disease among preschool children in El Salvador.

The nutritional status of preschool children in a rural El Salvadoran population was assessed quarterly for 1 year using height, weight and arm circumference measurements in order to define seasonal changes in malnutrition. Seasonal patterns in the incidence of reported malnutrition and diarrheal disease from the local clinic serving the study population and on the national level for EL Salvador were also assessed and were compared with field measurements. Results indicated a similar seasonal increase in both measured malnutrition and in the reported incidence of malnutrition and diarrheal disease occurring at the onset of the rainy season. The results confirm the existence and indicate the magnitude of seasonal changes in malnutrition and diarrheal disease in a preschool population.

Anthropometric nutrition status and diarrhea prevalence in children in El Salvador.

Data are presented to quantify the relationship between nutritional status and diarrheal disease reported in a 1-week period in children in El Salvador. A strong association was observed between reported diarrhea and combined wasting (defined by low weight-for-height) and stunting (defined by low height-for-age). This association held for all age groups studied and was consistently observed in the seasons of low and high prevalence of malnutrition. There were also significant associations between reported diarrhea and wasting alone, low weight-for-age, and low arm circumference. No consistent association was observed between reported diarrhea and stunting or chronic undernutrition as defined by low height-for-age, suggesting that short stature is not, by itself, a risk factor for diarrhea. Previously defined seasonal patterns of malnutrition for El Salvador as a whole were confirmed and appear to affect some geographic subregions more severely than others. Definition of these regional and seasonal patterns of malnutrition and their association with diarrhea has implications for the targeting and timing of nutrition interventions.

The behavioral risk factor surveys: I. State-specific prevalence estimates of behavioral risk factors.

The prevalence of most behavioral risk factors varies substantially among states. The prevalence of current cigarette smoking ranges from 22 percent to 38 percent. Estimates of alcohol use show geographic clustering, with lower rates in the southeastern states. The prevalence of sedentary lifestyle, uncontrolled hypertension, overweight, and seatbelt use differs markedly among states. These findings represent an initial step toward the analysis of state-specific baseline risk-factor data for use in developing state programs aimed at reducing the leading causes of death in the United States.

The behavioral risk factor surveys: III. Chronic heavy alcohol use in the United States.

Results of adult telephone interview data from aggregated state surveys show significant chronic alcohol use (two or more drinks per day) by 8.7 percent of the U.S. population. Rates are higher in men than in women (13.8 percent versus 4.0 percent, and higher in whites than in blacks (9.1 percent versus 4.5 percent). Women 25-44 years of age have significantly lower rates (2.9 percent) than women 18-24 (5.7 percent) or women 45-64 (4.6 percent). Also, rates are higher in heavy smokers (over one pack per day) than nonsmokers (22.4 percent versus 5.9 percent), among nonusers of seatbelts than users of seatbelts (10.5 percent versus 6.2 percent), and in those who reported driving after having had "too much" to drink than in those who did not (32.3 percent versus 7.5 percent). Overweight women (2.7 percent) and those who eat in response to stress (3.1 percent) have lower rates of chronic heavy alcohol use than those without these risk factors. Alcohol-related morbidity contributes substantially to the loss of productive life. We conclude that examining alcohol consumption in the light of other lifestyle behaviors would help in the design of effective prevention programs based on multiple risk factor interventions.