GROWTH PARAMETRES AND THEIR ASSESSMENT by Dr. Azher Shah Associate Professor Department of Paediatrics Azra Naheed Medical College, LAHORE

Goals Methods for Nutritional Assessment? Growth? Development? Methods for Nutritional Assessment? Growth Parametres? How to utilize growth charts?

Growth & Development Growth Quantitative increase in size of body and can be measured in terms of HEIGHT and WEIGHT Development Qualitative functional maturation assessed in terms of acquisition of skills and ability to cope with the situation

Growth & Development (Cont…) Growth and development are so closely related that they are usually assessed simultaneously

Growth Assessment Goals of Growth Assessment To determine if there are growth abnormalities that point to the presence of an underlying disease To prevent nutritional disorders and the increased morbidity and mortality that accompany them INTRODUCTION — The goal of nutritional assessment in childhood is to determine if there are growth abnormalities that point to the presence of an underlying disease, and also to prevent nutritional disorders and the increased morbidity and mortality that accompany them. To meet these goals, pediatric clinicians must know the risk factors for obesity and malnutrition and must understand the normal and abnormal patterns of growth and the changes in body composition during childhood and adolescence. In addition, they must be able to accurately perform and interpret the results of the nutritional evaluation. Nutritional assessment is the quantitative evaluation of nutritional status. A comprehensive nutritional assessment has four components: Dietary, medical, and medication history Physical examination Growth, anthropometric, and body composition measurements Laboratory tests The measurements of growth are reviewed here. The measurement of body composition, the dietary history, and clinical and laboratory features of nutritional disorders are discussed separately.

Growth Assessment (Cont…) Nutritional Assessment It is quantitative evaluation of nutritional status Four components Dietary, medical, and medication history Physical examination Anthropometric and body composition measurements Laboratory tests INTRODUCTION — The goal of nutritional assessment in childhood is to determine if there are growth abnormalities that point to the presence of an underlying disease, and also to prevent nutritional disorders and the increased morbidity and mortality that accompany them. To meet these goals, pediatric clinicians must know the risk factors for obesity and malnutrition and must understand the normal and abnormal patterns of growth and the changes in body composition during childhood and adolescence. In addition, they must be able to accurately perform and interpret the results of the nutritional evaluation. Nutritional assessment is the quantitative evaluation of nutritional status. A comprehensive nutritional assessment has four components: Dietary, medical, and medication history Physical examination Growth, anthropometric, and body composition measurements Laboratory tests The measurements of growth are reviewed here. The measurement of body composition, the dietary history, and clinical and laboratory features of nutritional disorders are discussed separately.

Anthropometry Height Weight Body Mass Index Head Circumference GROWTH STANDARDS — Growth measurements are the most important components of the nutritional assessment of children because normal growth patterns are the gold standard by which clinicians assess the health and well-being of children. A normal growth pattern does not guarantee overall health; however, children with abnormal growth patterns frequently have nutritional complications of specific clinical disorders (eg, cystic fibrosis, inflammatory bowel disease) or poor socioeconomic conditions. Altered growth patterns are a late consequence of nutritional insult, regardless of the cause of nutritional deprivation. Thus, careful surveillance for nutrition problems, particularly in children who are at risk, is necessary for the prevention of nutritional morbidity. Height, weight, body mass index, and head circumference measurements are the mainstay of the nutritional assessment of the child. These measurements are useful only if the clinician is able to correctly interpret them by converting absolute values to relative standards for the appropriate reference population.

Growth Charts Growth measurements should be plotted on growth charts Growth is most rapid in healthy children during early infancy and adolescence Serial measurements must be obtained Children whose length, height, or weight measurements fall below the 5th percentile, above the 95th percentile, or cross two major centile curves are at nutritional risk Growth measurements should be plotted on growth charts that provide a reference for the population being measured. In the United States, as an example, growth charts prepared by the Centers for Disease Control and National Center for Health Statistics (CDC/NCHS), based upon data from five national health examination surveys and five supplementary data sources, should be used (show figure 1A-1D, show figure 2A-2D, show figure 3A-3B, and show figure 4A-4B) (www.cdc.gov/growthcharts) [1] . Growth is most rapid in healthy children during early infancy and adolescence. (See "Normal growth patterns in infants and prepubertal children" and see "Normal puberty"). Serial measurements must be obtained to determine if the growth pattern is truly abnormal or is a normal variant (eg, constitutional short stature or the rechanneling of normal growth curves). Children whose length, height, or weight measurements fall below the 5th percentile, above the 95th percentile, or cross two major centile curves are at nutritional risk and merit further consideration. As an example, if a child's weight falls from the 25th to the 10th percentile during one year, the clinician should investigate for an explanation, including signs and symptoms of underlying disease.

WHO Child Growth Standards WHO growth charts describe normal child growth from birth to 5 years under optimal environmental conditions These standards can be applied to all children everywhere The reference lines on the WHO growth charts are either percentile lines or z-scores The WHO standards define a population that is somewhat longer and leaner than the CDC references; this discrepancy is most dramatic during mid and late infancy The WHO standards are less likely to categorize a child as undernourished, and more likely to categorize a child as overweight WHO child growth standards — These growth standards, developed by the World Health Organization Multicentre Growth Reference Study, describe normal child growth from birth to 5 years under optimal environmental conditions (www.who.int/childgrowth/standards/en/) [2,3] . These standards can be applied to all children everywhere, regardless of ethnicity, socioeconomic status, and type of feeding. A pooled sample from six participating countries was used for the development of an international standard of growth. In addition, standardized body mass index (BMI) charts for infants to 5 years of age were developed. The reference lines on the WHO growth charts are either percentile lines or z-scores; z-scores are units of standard deviation from the median. (See "Z-scores" below). The WHO standards define a population that is somewhat longer and leaner than the CDC references; this discrepancy is most dramatic during mid- and late infancy. The WHO standards are less likely to categorize a child as undernourished, and more likely to categorize a child as overweight [4,5] . This probably relates to the fact that the WHO standards were derived from multiple countries, including those that have a lower obesity rate than the United States, whereas the CDC references are derived from the US population. When the concern is about overweight or obesity, the CDC references are preferable, because most risk thresholds and clinical recommendations have been based on the CDC reference. The CDC and the American Academy of Pediatrics are collaborating to develop additional guidance for appropriate use of these growth charts for monitoring growth within the US population (www.cdc.gov/GROWTHCHARTS/who_standards.htm). (See "Body mass index (BMI)" below).

Length or Height Length is measured in children younger than 2 years who are measured in the recumbent position Height or stature is measured in children older than 2 years who are measured while standing Measurement should be performed three times to improve accuracy, and the mean should be plotted on a standardized growth chart For a given individual, measured length is typically greater than standing height LENGTH OR HEIGHT — Length or height measurements require a firm, flat, horizontal, or vertical surface with perpendicular surfaces at each end [6] . Length is measured in children younger than 2 to 3 years who are measured in the recumbent position. Height or stature is measured in children older than 2 to 3 years who are measured while standing. Length and stature should be measured to the nearest 0.1 cm [7] . Ideally, the measurement should be performed three times to improve accuracy, and the mean should be plotted on a standardized growth chart. For children ages 2 to 3 years, either length or height may be used, but the measurements must be plotted on the corresponding length-for-age or stature-for-age growth chart. For a given individual, measured length is typically greater than standing height. Estimates from knee-height — Alternative measurements to monitor linear growth for children with spinal deformities or extremity contractures include upper arm length and knee-height. Standard curves exist for these measurements. Knee-height is the distance from the surface of the thigh, just proximal to the patella, to the sole of the foot when the knee and the foot are bent at a 90º angle. Knee-height is measured with a caliper designed for this purpose. Equations to estimate the height in centimeters from the knee-height measurement for children 6 to 18 years include the following : White children:         Boys:  height = 40.54 + (2.22 x knee height)         Girls:  height = 43.21 + (2.15 x knee height) Black children:         Boys:  height = 39.60 + (2.18 x knee height)         Girls:  height = 46.59 + (2.02 x knee height) A second alternative is to use the following equation (based on data from children with cerebral palsy, younger than 12 years of age):         Height = 24.2 + (2.69 x knee height)

Length or Height (Cont…) Average length at birth is 50 cm Increases 25 cm in first year of life At 3 years 90 cm At 4 years 100 cm Then height increases by 5 cm / year until puberty when growth spurt of 9-10 cm / year for 2-3 years

Length or Height in Centimeter Age Length or Height in Centimeter At Birth 50 At 1 year 75 2-12 years [Age(years)x6]+77

Weight Weight measurements should be obtained on a scale that has been calibrated properly Infant should be weighed without diapers and to the nearest 0.01 kg Older child should be measured without shoes, in little or no outer clothing, and to the nearest 0.1 kg Measurement should be plotted on a standardized growth chart

Weight (Cont…) Average weight at birth is 3.2 kg (7 lbs) Birth weight is doubled at 5-6 months of age Tripled at one year 4 times at 2 years of age Annual increase is about 2 Kg / year till puberty

Age Weight (kg) At Birth 2.50-3.25 3-12 months Age (months) + 9 2 1-6 years [Age(years)x2]+8 7-12 years [Age(years)x7]-5

Body Mass Index (BMI) BMI characterizes the relative proportion between the child's weight and height BMI is calculated from the weight and square of the height as BMI = body weight (kg) ÷ height (meters) squared BMI a valid predictor of adiposity, and is therefore the best clinical standard for defining obesity in children and adults BMI greater than the 85th percentile is overweight and greater than the 95th percentile is obese BMI less than the 5th percentile is underweight

Weight for Height Like BMI, the ratio of weight to height can be used to predict adiposity For children aged 0 to 2 years, the ratio of weight to length is generally used instead of BMI For children aged 3 to 5 years, BMI for age and weight-for-height measures predict adiposity equally well A child's weight-for-height can be compared to normal standards using a chart Like BMI, the ratio of weight to height can be used to predict adiposity. For children aged 0 to 2 years, the ratio of weight to length is generally used instead of BMI (show figure 5A-5B and show calculator 3). (See "Etiology and evaluation of failure to thrive (undernutrition) in children younger than two years"). For children aged 3 to 5 years, BMI for age and weight-for-height measures predict adiposity equally well. Nonetheless, BMI is generally used for assessing an overweight child, because most risk thresholds and clinical recommendations have been based on the BMI percentiles (using the CDC reference charts). A child's weight-for-height can be compared to normal standards using a chart or calculator for boys (show calculator 8) or for girls (show calculator 9). For children aged 6 to 19 years, BMI for age is slightly better than weight-for-height in predicting adiposity [12] . (See "Body Mass Index (BMI)" below).

Head Circumference Head circumference is measured at the maximum diameter through the glabella and occiput to the nearest 0.01 cm Recorded value should be the mean of three measurements It is measured in children from birth to 3 years of age because this is the period of rapid brain growth It should be measured in older children with abnormal growth because it may be helpful in determining the etiology Measurement should be plotted on a standardized growth chart Head circumference is measured at the maximum diameter through the glabella and occiput to the nearest 0.01 cm Recorded value should be the mean of three measurements Head circumference is measured in children from birth to 3 years of age because this is the period of rapid brain growth Head circumference also should be measured in older children with abnormal growth because it may be helpful in determining the etiology Measurement should be plotted on a standardized growth chart. Abnormal head growth is defined as a head circumference (also called fronto-occipital circumference) greater than two standard deviations above or below the mean for a given age, gender, and gestation. Microcephaly is a head circumference greater than two standard deviations below the mean (show figure 3A-3B and show Calculator 10). Macrocephaly is a head circumference greater than two standard deviations above the mean. The evaluation and interpretation of abnormal head growth is discussed in detail separately. (See "Etiology and evaluation of macrocephaly in infants and children" and see "Etiology and evaluation of microcephaly in infants and children").

Head Circumference Abnormal head growth is defined as a head circumference (also called fronto-occipital circumference) greater than two standard deviations above or below the mean for a given age, gender, and gestation Microcephaly is a head circumference greater than two standard deviations below the mean Macrocephaly is a head circumference greater than two standard deviations above the mean Head circumference is measured at the maximum diameter through the glabella and occiput to the nearest 0.01 cm Recorded value should be the mean of three measurements Head circumference is measured in children from birth to 3 years of age because this is the period of rapid brain growth Head circumference also should be measured in older children with abnormal growth because it may be helpful in determining the etiology Measurement should be plotted on a standardized growth chart. Abnormal head growth is defined as a head circumference (also called fronto-occipital circumference) greater than two standard deviations above or below the mean for a given age, gender, and gestation. Microcephaly is a head circumference greater than two standard deviations below the mean (show figure 3A-3B and show Calculator 10). Macrocephaly is a head circumference greater than two standard deviations above the mean. The evaluation and interpretation of abnormal head growth is discussed in detail separately. (See "Etiology and evaluation of macrocephaly in infants and children" and see "Etiology and evaluation of microcephaly in infants and children").

Growth Velocity (for Height) Height velocity measurements are the most sensitive in detecting growth abnormalities early in the course of all types of chronic illness Any child older than 2 years whose height velocity is less than 4 cm/year should be monitored carefully for progressive nutritional deficits During puberty, peak height velocity is 5 to 11 cm/year in boys, and 6 to 10 cm/year in girls; the age of peak height velocity varies substantially GROWTH VELOCITY — Incremental growth charts that characterize height and weight velocities over time are valuable in assessing the growth of children, particularly those with specific clinical disorders [13] . Height velocity measurements are the most sensitive in detecting growth abnormalities early in the course of all types of chronic illness [14] . Any child older than 2 years whose height velocity is less than 4 cm/year should be monitored carefully for progressive nutritional deficits or causes of short stature, because at least 95 percent of children grow faster than 4 cm/year [15] . During puberty, peak height velocity is 5 to 11 cm/year in boys, and 6 to 10 cm/year in girls; the age of peak height velocity varies substantially (show figure 7A-7B). (See "Diagnostic approach to short stature"). Any prepubertal child whose weight velocity is less than 1 kg per year should be monitored carefully for progressive nutritional deficits, because about 95 percent of children gain weight faster than this rate in a well-nourished population [16] . During puberty, weight gain is more rapid; peak weight velocity is generally between 1 and 4 kg per six months in a healthy population.

Growth Velocity (for Weight) Any prepubertal child whose weight velocity is less than 1 kg per year should be monitored carefully for progressive nutritional deficits During puberty, weight gain is more rapid; peak weight velocity is generally between 1 and 4 kg per six months in a healthy population GROWTH VELOCITY — Incremental growth charts that characterize height and weight velocities over time are valuable in assessing the growth of children, particularly those with specific clinical disorders [13] . Height velocity measurements are the most sensitive in detecting growth abnormalities early in the course of all types of chronic illness [14] . Any child older than 2 years whose height velocity is less than 4 cm/year should be monitored carefully for progressive nutritional deficits or causes of short stature, because at least 95 percent of children grow faster than 4 cm/year [15] . During puberty, peak height velocity is 5 to 11 cm/year in boys, and 6 to 10 cm/year in girls; the age of peak height velocity varies substantially (show figure 7A-7B). (See "Diagnostic approach to short stature"). Any prepubertal child whose weight velocity is less than 1 kg per year should be monitored carefully for progressive nutritional deficits, because about 95 percent of children gain weight faster than this rate in a well-nourished population [16] . During puberty, weight gain is more rapid; peak weight velocity is generally between 1 and 4 kg per six months in a healthy population.

Malnutrition The degree of acute and chronic malnutrition can be assessed clinically using various anthropometric measurements During periods of nutritional deprivation, weight deficits occur initially, followed by length or height deficits and finally by head circumference deficits

Obesity The clinical evaluation of a child with obesity includes assessment of the BMI or weight-to-height ratio Precise measurement of the body fat content is not generally necessary or helpful for clinical decision-making

Short or Tall Stature Radiographic studies of bone age can help to clarify the presence of abnormal growth patterns

Summary Growth and Development Growth parameters Use standardized growth charts

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