1 / 47

CDC Growth Charts 2000

CDC Growth Charts 2000 . Centers for Disease Control and Prevention National Center for Chronic Disease Prevention and Health Promotion Division of Nutrition and Physical Activity Maternal and Child Nutrition Branch. Revised June 2002. Training Objectives.

alec
Download Presentation

CDC Growth Charts 2000

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CDC Growth Charts 2000 Centers for Disease Control and Prevention National Center for Chronic Disease Prevention and Health Promotion Division of Nutrition and Physical Activity Maternal and Child Nutrition Branch Revised June 2002

  2. Training Objectives • Science behind development of growth charts • Rationale for including BMI-for-age • Using BMI-for-age as a screening tool

  3. What growth charts are available?

  4. New Features of the Growth Charts • BMI-for-age charts (2-20 years) • 85th percentile (at risk of overweight) • 3rd and 97th percentiles available • Lowerlimits oflength (45 vs. 49 cm) and height (77 vs. 90 cm) extended • Smoothed percentile curves and z-scores agree • Correction in the disjunction

  5. Disjunction: Smoothed in New Charts 120 120 1977 2000 110 110 100 100 90 90 Length/height in cm Length/height in cm 80 80 70 70 60 60 50 50 40 40 48 42 0 6 12 18 24 30 36 54 60 0 12 18 24 30 36 42 48 54 60 6 Age in month Age in month

  6. Reference Population for CDC Growth Charts • Racially and ethnically diverse • Infants: Birth to 36 months • Children and Adolescents: 2 to 20 years • Breast- and formula-fed infants

  7. Reference Data Sets: Birth to 36 Months

  8. Reference Data Sets: 2 to 20 Years

  9. Exclusions from the Reference Data • Very low birth weight (VLBW) infants (<1500 g) were excluded because they have different growth patterns • NHANES III weight data for 6+ year olds were excluded to avoid an upward shift in weight-for-age and BMI-for-age curves

  10. Age-Adjusted Prevalence of Overweight1 From NHANES I to III 2 1>95th percentile BMI-for-age 2 http://www.cdc.gov/nchs/products/pubs/pubd/hestats/overwght99.htm Percent Sex and Age Group

  11. CDC Growth Charts Are for All Racial and Ethnic Groups Combined • Environmental influences appear to contribute to variations in growth more than genetic influences • Inadequate sample data for racial- and ethnic- specific charts • The effect of race and ethnicity on BMI-for- age is unclear

  12. Age Adjusted Prevalence of Low Height-for-Age by Ethnic Groups, Children Aged 0 to 5 Years1 Percentage Year of Visit 1 Mei, Yip and Trowbridge, Asia Pacific J Clin Nutr 1998; 7(2): 111-116

  13. Breast-Fed vs. Formula-Fed Infants • Mode of infant feeding can influence growth • New charts represent the combined growth patterns of breast-fed and formula-fed infants • Working group of the World Health Organization (WHO) is developing growth charts for infants and children through age 5 using data collected on infants following WHO feeding recommendations

  14. Indicators of Nutritional Status <5th percentile >95th percentile Head circumference-for-age Stunting/shortness length or stature-for-age <5th percentile Underweight weight-for-length BMI-for-age <5th percentile

  15. Indicators of Nutritional Status Overweight Weight-for-length BMI-for-age >95th percentile Risk of overweight BMI-for-age 85th to 95th percentile

  16. Prevalence of Nutritional Status Indicators New Reference Curves Compared with Old Curves* < 2 Years Old Change in Prevalence Nutrition Indicator Stunting/shortness length-for-age <5th 1% to 2% lower Underweight weight-for-length <5th 1% to 2% higher Overweight weight-for-length >95th 2% lower for females 2% higher for males * NHANES III

  17. Prevalence of Nutritional Status Indicators New Reference Curves Compared with Old Curves* Children 2 to 5 years of age Nutrition Indicator Change in Prevalence Stunting/shortness stature-for-age <5th 1% lower 3% to 4% higher Underweight** <5th No change for females 1% higher for males Overweight** 95th * NHANES III **BMI-for-age, weight-for-stature

  18. What Is BMI? • Body mass index (BMI) = weight (kg)/height (m)2 • BMI is an effective screening tool; it is not a diagnostic tool • For children, BMI is age and gender specific, so BMI-for-age is the measure used

  19. Advantages of BMI-for-Age • Provides a reference for adolescents that was not previously available • Consistent with adult index so it can be used continuously from 2 years of age to adulthood • Tracks childhood overweight into adulthood

  20. Tracking BMI-for-Age from Birth to 18 Years with Percent of Overweight Children who Are Obese at Age 251 Whitaker et al. NEJM:1997;337:869-873

  21. Advantages of BMI-for-Age • BMI-for-age relates to health risks • Correlates with clinical risk factors for cardiovascular disease including hyperlipidemia, elevated insulin, and high blood pressure • BMI-for-age during pubescence is related to lipid levels and high blood pressure in middle age

  22. BMI-for-Age Compares Well with • Weight-for-stature measurements 1 • Measures of body fat Mei et al., Am J Clin Nutr 2002;75:978-85.

  23. Why Use BMI-for-Age? • Recommended by expert committees to evaluate overweight • Guidelines for Overweight in Adolescent Preventive Services (Am J Clin Nutr 1994;59:307-316) • Obesity Evaluation and Treatment: Expert Committee Recommendations (Pediatrics 1998 Sept;(102)3:e 29) • Assessment of Childhood and Adolescent Obesity: International Obesity Task Force (Am J Clin Nutr 1999, 70,suppl)

  24. 35 35 30 30 25 25 20 Weight (kg) BMI 15 20 10 15 5 10 0 80 90 100 110 120 130 24 72 120 168 216 Stature (cm) Age (months) Shape of Weight-for-Stature Curve versus BMI-for-Age Curve 95th 95th 50th 5th 50th 5th

  25. For Children, BMI Changes with Age BMI BMI Example: 95th Percentile Tracking Age BMI 2 yrs 19.3 4 yrs 17.8 9 yrs 21.0 13 yrs 25.1 Boys: 2 to 20 years BMI BMI

  26. BMI BMI Boys: 2 to 20 years BMI BMI Shape of BMI-for-Age Growth Curve: “Adiposity” Rebound (AR) Example: Early AR Age (mos) BMI 26 18.2 32 17.4 38 18.5 41 18.7 BMI

  27. BMI-for-Age Cutoffs > 95th percentile Overweight 85th to < 95th Risk of overweight percentile < 5th percentile Underweight

  28. Performance of BMI-for-Age as a Screening Tool • Using the 85th and 95th percentiles as cut points, few children are incorrectly identified as over-fat but some over-fat children will be missed. • It is desirable to correctly identify those children not at risk of overweight or overweight.

  29. Calculating BMI with the Metric System Formula:weight (kg)/[height (m)]2 Calculation: [weight (kg)/ height (cm)/ height (cm)] x 10,000 Example: A child’s weight=16.9 kg and height=105.4 cm BMI = [16.9 kg / 105.4 cm / 105.4 cm] x 10,000 = 15.2

  30. Calculating BMI with the English System Formula: weight (lb)/[height (in)]2x 703 Calculation: [weight (lb)/height (in)/height (in)] x 703 Example: A child’s weight = 37 pounds, 4 ounces and height = 41 1/2 inches (convert fractions to decimal value) BMI = [37.25 lb / 41.5 in / 41.5 in] x 703 = 15.2

  31. Can you see risk? • This boy is 3 years, 3 weeks old. • Is his BMI-for-age • ->85th to <95th percentile: at risk for overweight? Photo from UC Berkeley Longitudinal Study, 1973

  32. BMI BMI Boys: 2 to 20 years BMI BMI Plotted BMI-for-Age Measurements: Age=3 y 3 wks Height=100.8 cm (39.7 in) Weight=18.6 kg (41 lb) BMI=18.3 BMI-for-age=>95th percentile overweight

  33. Can you see risk? • This girl is 4 years, 4 weeks old. • Is her BMI-for-age • ->85th to <95th percentile: at risk for overweight? Photo from UC Berkeley Longitudinal Study, 1974

  34. Plotted BMI-for-Age Measurements: BMI BMI Age= 4 y 4 wks Height=106.4 cm (41.9 in) Weight=15.7 kg (34.5 lb) BMI=13.9 BMI-for-age= 10th percentile Normal Girls: 2 to 20 years BMI BMI

  35. Can you see risk? • This girl is 4 years old. • Is her BMI-for-age • ->85th to <95th percentile: at risk for overweight? Photo from UC Berkeley Longitudinal Study, 1973

  36. Plotted BMI-for-Age Measurements: Age=4 y Height=99.2 cm (39.2 in) Weight=17.55 kg (38.6 lb) BMI=17.8 BMI-for-age= between 90th –95th percentile At risk for overweight BMI BMI Girls: 2 to 20 years BMI BMI

  37. BMI BMI Boys: 2 to 20 years BMI BMI Accurate Measurements are Critical 5 1/2 year old boy Weight: 41.5 lb Height: 43 in BMI= 15.8 BMI-for-age=50th %tile Inaccurate height measurement: 42.25 BMI=16.3 BMI-for-age=75th %tile

  38. Interpreting the BMI-for-Age Cutoffs > 95th percentile Overweight 85th to < 95th Risk of overweight percentile < 5th percentile Underweight

  39. Interpreting the BMI-for-Age Chart • BMI-for-age indicates a child’s weight in relation to his/her height for a specific age and gender • Need a series of BMI plots to determine the growth trend • If indices deviate from normal growth patterns, further assessment may be needed

  40. Example: “Sam” • Name: Sam • Weight: 37 lb 4 oz (16.9 kg) • Height: 41.5 inches (105 cm) • Age: 3.5 years • BMI: 15.2

  41. BMI BMI Boys: 2 to 20 years BMI BMI Sam’s BMI Plotted on Boy’s BMI-for-Age Chart • Interpretation: • Sam’s BMI-for-age is slightly below the 25th %tile so it falls within the normal range. • Of 100 boys who are the same age, fewer than 25 have a BMI-for-age lower than Sam’s.

  42. Summary of Using BMI-for-Age • BMI-for-age is the recommended method for screening overweight and underweight • For children, BMI is age and gender specific; for adults there are fixed cut points • Accurate and periodic measurements are important elements of any anthropometric screening

  43. Steps to Plot BMI-for-Age • Obtain accurate weight and height measurements • Select the appropriate growth chart • Record the data • Calculate BMI • Plot measurements • Interpret plotted measurements

  44. Please visit: http://www.cdc.gov/growthcharts/ • For additional training materials related to the growth charts • For tools related to the growth charts • To download the growth charts

  45. www.cdc.gov/growthcharts

More Related