Kenneth J. Ellis, Ph.D.
Professor of Pediatrics, Baylor College of Medicine
The Biological Diversity of Growth: Body Composition in Infancy, Childhood, Adolescence and Early Adulthood
The objective of our research lab is to establish Reference Standards for the normal biological diversity in body composition during growth for different ethnic groups. We are evaluating new measurement methods and developing mathematical models that describe and predict body compositional changes during growth. Reference Models for the fetus, infant, child, and adolescent are being developed.
Body composition at any age can be viewed as the net cumulative integration of differences in growth velocity, initial composition at birth, age at onset of puberty, basal metabolism, changes in hormonal levels, genetic makeup, history of illnesses, nutrient availability, and physical activity level. Significant changes in tissue mass and its composition occur during growth. Any meaningful assessment of nutrient requirements for normal growth requires accurate and precise data on changes in body composition for the individual child.
The routine measurements available at the CNRC include total body potassium for body cell mass, dual-energy x-ray absorptiometry for bone mineral, fat, and lean tissue mass, and bioelectrical impedance for body fatness, and prompt-gamma activation for body nitrogen, Fourier-transformed infrared reactance for deuterium dilution (body water), and x-ray florescence for bromine dilution (extracellular water). Computed tomography (CT) is used for the assessment of abdominal fat distribution (subcutaneous fat vs visceral fat). In addition, several instruments are under develop or evaluation for use with preterm and term infants. These include an infant-sized air displacement plethysmograph, ultrasound assessment of bone, and light reflectance for subcutaneous fat measurements.
Ellis KJ. Evaluation of body composition in neonates and infants. Semin Fetal Neonatal Med. 2007; 12: 87-91.
Abrams SA, Griffin IJ, Hawthorne KM, Ellis KJ. Effect of prebiotic supplementation and calcium intake on body mass index. J Pediatr 2007; 151: 293-298.
Butte NF, Cai G, Cole SA, Wilson TA, Fisher JO, Zakeri IF, Ellis KJ, Comussie AG. Metabolic and behavioral predictors of weight gain in Hispanic children: the Viva la Familia Study. Am J Clin Nutr 2007; 85: 1478-1485.
Ellis KJ, Grund B, Visnegarwala F, Thackeray L, Miller CG, Chesson CE, El-Sadr W, Carr A. Visceral and subcutaneous adiposity measurements in adults: influence of measurement site. Obesity 2007;15: 1441-1447.
Ellis KJ, Yao M, Shypailo RJ, Urlando A, Wong WW, Heird WC. Body composition assessment in infancy: air-displacement plethysmography compared with a reference 4-compartment model. Am J Clin Nutr. 2007; 85: 90-95.
Motil KJ, Schultz RJ, Abrams S, Ellis KJ, Glaze DG. Fractional Calcium Absorption Is Increased in Girls with Rett Syndrome. J Pediatr Gastroenterol Nutr. 2006; 42: 419-426.
D’Amico S, Shi J, Sekhar RV, Jahoor F, Ellis KJ, Rehman K, Willis J, Maldonado M, Balasubramanyam A. Physiologic growth hormone replacement improves fasting lipid kinetics in patients with HIV lipodystrophy syndrome. Am J Clin Nutr 2006; 6: 204-211.
Abrams SA, Griffin IJ, Hawthorne KM, Liang L, Gunn SK, Darlington G, Ellis KJ. A combination of prebiotic short- and long-chain inulin-type fructans enhances calcium absorption and bone mineralization in young adolescents. Am J Clin Nutr. 82(2):471-476, 2005.
Hardin DS, Rice J, Cohen RC, Ellis KJ, Nick JA. The metabolic effects of pregnancy in cystic fibrosis. Obstet Gynecol. 2005 Aug;106(2):367-75. Erratum in: Obstet Gynecol. 106(4):869, 2005.
Abrams SA, Griffin IJ, Hawthorne KM, Chen Z, Gunn SK, Wilde M, Darlington G, Shypailo RJ, Ellis KJ. Vitamin D receptor Fok1 polymorphisms affect calcium absorption, kinetics, and bone mineralization rates during puberty. J Bone Miner Res. 20(6):945-953, 2005.
Hardin DS, Ahn C, Prestidge C, Seilheimer DK, Ellis KJ. Growth hormone improves bone mineral content in children with cystic fibrosis. J Pediatr Endocrinol Metab. 18(6):589-595, 2005.
Shypailo RJ, Ellis KJ. Bone Assessment in Children: Comparison of Fan-Beam DXA Analysis. J Clin Densitom. 8(4):445-453, 2005.
Koo WW, Hammami M, Shypailo RJ, Ellis KJ. Bone and body composition measurements of small subjects: discrepancies from software for fan-beam dual energy X-ray absorptiometry. J Am Coll Nutr. 23(6):647-650, 2004.
Vandamme TF, Ellis KJ. Issues and challenges in developing ruminal drug delivery systems. Adv Drug Deliv Rev. 56(10):1415-1436, 2004.
Butte NF, Wong WW, Treuth MS, Ellis KJ, O'Brian Smith E. Energy requirements during pregnancy based on total energy expenditure and energy deposition. Am J Clin Nutr. 79(6):1078-1087, 2004.
Hardin DS, Ellis KJ, Rice J, Doyle ME. Protease inhibitor therapy improves protein catabolism in prepubertal children with HIV infection. J Pediatr Endocrinol Metab. 17(3):321-325, 2004.
Ellis KJ, Shypailo RS, Steinberg FM, Lewis RD, Young RL, Wong WW. Reproducibility of fan-beam DXA measurements in adults and phantoms. J Clin Densitom. 7(4):413-418, 2004.
Shi J, Sekhar RV, Balasubramanyam A, Ellis K, Reeds PJ, Jahoor F, Sharma MD. Short- and long-term effects of growth hormone (GH) replacement on protein metabolism in GH-deficient adults. J Clin Endocrinol Metab. 88(12):5827-5833, 2003.
Butte NF, Ellis KJ, Wong WW, Hopkinson JM, Smith EO. Composition of gestational weight gain impacts maternal fat retention and infant birth weight. Am J Obstet Gynecol. 189(5):1423-1432, 2003.
Ellis KJ, Shypailo RJ, Wong WW, Abrams SA. Bone mineral mass in overweight and obese children: diminished or enhanced? Acta Diabetol. 40 Suppl 1:S274-S277, 2003.
Butte NF, Ellis KJ. Comment on "Obesity and the environment: where do we go from here?". Science. 301(5633):598, 2003.
Dolson GM, Ellis KJ, Johnson ML, Adrogue HJ. Incidence and consequences of total body potassium depletion in chronic hemodialysis patients. Front Biosci. 8:a126-a132, 2003.
Ellis KJ. Human body composition: in vivo methods. Physiological Reviews 2000; 80:649-680.
Butte NF , Hopkinson JM, Wong WW, Smith EO, Ellis KJ. Body composition during the first two years of life: an updated reference. Ped Res 2000; 47: 578-585.
Ellis KJ, Shypailo RJ, Abrams SA, Wong WW. The reference child and adolescent models of body composition: a contemporary comparison. Annual New York Acad Sci 2000: 904; 374-382.
Ellis KJ, Shypailo RJ, Hardin DS, Perez MD, Motil KJ, Wong WW, Abrams SA. Z-score prediction model for assessment of bone mineral content in pediatric diseases. J Bone Min Res 2001; 16: 1658-1664.
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