Comparison of changes in growth percentiles of US children on CDC 2000 growth charts with corresponding changes on WHO 2006 growth charts

Growth monitoring as an early detection tool: a systematic review

Growth monitoring of apparently healthy children aims at early detection of serious underlying disorders. However, existing growth-monitoring practices are mainly based on suboptimal methods, which can result in delayed diagnosis of severe diseases and inappropriate referrals. We did a systematic review to address two key and interconnected questions underlying growth monitoring: which conditions should be targeted, and how should abnormal growth be defined? We systematically searched for studies reporting algorithms for growth monitoring in children and studies comparing the performance of new WHO growth charts with that of other growth charts. Among 1556 identified citations, 69 met the inclusion criteria. Six target conditions have mainly been studied: Turner syndrome, coeliac disease, cystic fibrosis, growth hormone deficiency, renal tubular acidosis, and small for gestational age with no catch-up after 2 or 3 years. Seven algorithms to define abnormal growth have been proposed in the past 20 years, but their level of validation is low, and their overall sensitivities and specificities vary substantially; however, the Grote and Saari clinical decision rules seem the most promising. Two studies reported that WHO growth charts had poorer performance compared with other existing growth charts for early detection of target conditions. Available data suggest a large gap between the widespread implementation of growth monitoring and its level of evidence or the clinical implications of early detection of serious disorders in children. Further investigations are needed to standardise the practice of growth monitoring, with a consensus on a few priority target conditions and with internationally validated clinical decision rules to define abnormal growth, including the selection of appropriate growth charts.

The prevalence of rapid weight gain in infancy differs by the growth reference and age interval used for evaluation

BACKGROUND

Infant rapid weight gain (RWG) may predict subsequent obesity, but there are inconsistencies in the growth references and age intervals used for assessment.

METHODS

This study evaluated whether the prevalence of RWG (an increase of >0.67 in weight-for-age z-score) differed by growth reference (2006 WHO standards vs 2000 CDC references) and age interval of assessment (0-3, 0-6, 6-12 and 0-12 months). Pooled data from singleton term infants from two observational studies on maternal mood disorders during pregnancy were used (n = 161). Differences in RWG prevalence by growth reference and age interval were tested using Cochran's Q and McNemar's tests.

RESULTS

The CDC reference produced a higher RWG prevalence (14% of infants additionally categorized as RWG, p < 0.0001) within the 0-3 month age interval compared to the WHO standards; this pattern was reversed for the 6-12 and 0-12 month intervals. RWG prevalence did not differ across age interval within the WHO standards, but did differ with the CDC references (range: 22% for 0-3 months to 4.2% for 6-12 months, p < 0.0001).

CONCLUSIONS

Caution is advised when comparing studies with different criteria for RWG. Future studies should use the 2006 WHO standards and a consistent age interval of evaluation.

Comparison of Centers for Disease Control and Prevention and World Health Organization references/standards for height in contemporary Australian children: analyses of the Raine Study and Australian National Children's Nutrition and Physical Activity cohorts

AIM

(i) To compare the Centers for Disease Control and Prevention (CDC) reference and World Health Organization (WHO) standard/reference for height, particularly with respect to short stature and eligibility for growth hormone (GH) treatment by applying them to contemporary Australian children; (ii) To examine the implications for identifying short stature and eligibility for GH treatment.

METHODS

Children from the longitudinal Raine Study were serially measured for height from 1991 to 2005 (2-15-year-old girls (660) and boys (702) from Western Australia). In the cross-sectional Australian National Children's Nutrition and Physical Activity survey (2-16-year-old boys (2415) and girls (2379) from all states), height was measured in 2007. Heights were converted to standard deviation scores (SDSs) based on CDC and WHO.

RESULTS

Means and standard deviations of height-SDS varied between CDC and WHO definitions and with age and gender within each definition. However, both identified similar frequencies of short stature (<1st centile for GH eligibility), although these were very significantly less than the anticipated 1% (0.1-0.7%) of the Australian cohorts. Mean heights in the Australian cohorts were greater than both the WHO and CDC means.

CONCLUSIONS

Neither CDC nor WHO height standardisations accurately reflect the contemporary Australian child population. Australian children are taller than the CDC or WHO height means, and significantly less than 1% of Australian children are defined as being short using either CDC or WHO. This study suggests there may be a case for an Australian-specific standard/reference for height.

Neglect: failure to thrive and obesity

Medical providers need to monitor growth at every visit. Weight status is influenced by genetics, medical conditions, socioeconomic status, and family environment. Screening for food security and psychosocial risk factors is an integral tool to identify families at risk for nutritional deficits and child maltreatment. Nutritional rehabilitation is best accomplished in an outpatient, multidisciplinary setting. Medical neglect should be considered in failure to thrive and obesity when there is a serious risk of harm from identified medical complications, additional or worsening medical complications occurring despite a multidisciplinary approach, and/or non-adherence with the treatment plan.

WHO growth chart awareness among clinicians in Kentucky

OBJECTIVES

To examine children's growth chart use among clinicians and explore awareness of the Centers for Disease Control and Prevention's (CDC) recommendations for the use of World Health Organization (WHO) growth charts.

METHODS

A cross-sectional survey of pediatricians and family practitioners in Kentucky.

RESULTS

Only 29% of clinicians reported using WHO growth charts, with board-certified urban pediatricians more likely to be aware of the WHO growth charts and to recognize that CDC growth charts led them to overdiagnose infants as being underweight. Approximately one-fourth of respondents did not know the source of growth charts for their practice. Only 13% of clinicians discussed body mass index and other vital parameters with parents and provided copies of growth charts at the end of patient visits. Clinicians who provided copies of growth charts to parents were more likely to be nonacademic, board-certified pediatricians in urban areas with more than 10 years' experience.

CONCLUSIONS

More than 6 months after the CDC's recommendation to use WHO growth charts for children younger than 2 years old, few clinicians were familiar with and used the WHO charts. Increased awareness and training, increased availability of WHO growth charts, and adherence to the recommendations will result in more accurate growth calculations and avoid underidentification of infants at risk for overweight and obesity.

Systematic examination of infant size and growth metrics as risk factors for overweight in young adulthood

OBJECTIVE

To systematically examine infant size and growth, according to the 2006 WHO infant growth standards, as risk factors for overweight status in young adulthood in a historical cohort. Specifically, to assess: Whether accounting for length (weight-for-length) provides a different picture of risk than weight-for-age, intervals of rapid growth in both weight-for-age and weight-for-length metrics, and what particular target ages for infant size and intervals of rapid growth associate most strongly with overweight as a young adult.

PATIENTS/METHODS

Data analysis of 422 appropriate for gestational age white singleton infants enrolled in the Fels Longitudinal Study. Odds ratios (OR) for overweight and obesity in young adulthood (age 20-29) were calculated using logistic regression models for the metrics at each target age (0, 1, 3, 6, 9, 12, 18, 24 months) comparing ≥85(th) v. <85(th) percentile, as well as rapid growth (Δ≥0.67 Z-score) through target age intervals. Models accounted for both maternal and paternal BMI.

RESULTS

Infants ≥85(th) percentile of weight-for-age at each target age (except 3 months) had a greater odds of being overweight as a young adult. After accounting for length (weight-for-length) this association was limited to 12, and 18 months. Rapid weight-for-age growth was infrequently associated with overweight as a young adult. Rapid weight-for-length growth from 0 to 24 months, 1 to 6, 9, 12, 18, and 24 months and from 3 to 9, 12, 18, and 24 months was strongly associated with overweight status as a young adult.

CONCLUSIONS

The WHO weight-for-length metric associates differently with risk of being overweight as a young adult compared to weight-for-age. Intervals of rapid weight-for-length growth ranging from months (0-24), (1-12, 18, and 24) and (3-9, and 12) displayed the largest OR for being overweight as a young adult.

Evaluating Canadian children: WHO, NHANES or what?

AIM

The 2006 World Health Organization (WHO) growth charts have been widely adopted by Canadian dieticians for growth monitoring of Canadian children rather than the National Health and Nutrition Examination Survey (NHANES III) reference data. It has been unclear as to which is the most appropriate.

METHODS

We calculated height and weight z-scores of 3086 consecutive patients (1530 female, 49.6%) aged 0-5 years, attending outpatient clinics at a single tertiary care centre using reference data of the latest NHANES survey and the 2006 WHO growth charts. To address age dependency, data were stratified into age groups. Gender dependency was also investigated.

RESULTS

Using NHANES III reference intervals, medians of both height z-score (+0.24) and weight z-score (+0.32) were significantly non-zero. The WHO growth charts yielded medians of height z-score (-0.15) and weight z-score (+0.36) respectively, also significantly non-zero. When comparing both reference populations for the entire cohort, Canadian children had significantly different height z-scores whereas weight z-scores did not differ. Age classification revealed a significant age dependency with NHANES III charts yielding higher weight z-scores for up to 8 months and lower z-scores from 8 to 26 months. No significant differences were observed for older than 26 months. Throughout, height z-scores were significantly higher with NHANES III charts across all age groups, with a degree of overestimation higher in younger boys than older ones.

CONCLUSION

Our results reveal substantial differences between both reference populations and thus interpretation needs to be done with caution, especially when labelling results as abnormal.

The Importance of Definition in Diagnosing Obesity

The prevalence of childhood overweight and obesity in China has increased in recent decades. However, studies reported from China use several different definitions and growth references, making it difficult to compare the rates of obesity from different regions. It also makes it difficult to establish the extent of secular trends in obesity and to make international comparisons. This article reviews the definitions of childhood obesity used in Chinese studies published over the past 10 years. The majority (79%) of the Chinese studies used a definition of >120% of the mean value of the National Center for Health Statistics reference population to diagnose childhood obesity. Only 7 studies (9%) conducted in China measured childhood obesity using age-specific and sex-specific body mass index (BMI) cutoffs, including International Obesity Task Force cutoffs, Centers for Disease Control 2000 and World Health Organization 2006 BMI curves, and Chinese BMI curves. It is important that a consistent and applicable definition is used and all studies accurately define the obesity with growth reference, cutoff criteria, sample selection, and age distribution. The use of sex-specific and age-specific BMI cutoffs should be considered when undertaking future studies of obesity in Chinese children.