Idiopathic Short Stature
http://www.100md.com
《新英格兰医药杂志》
To the Editor: The clinical vignette provided by Lee (June 15 issue)1 raises some issues that require clarification. The vignette does not include data on growth velocity or levels of insulin-like growth factor I and insulin-like growth factor–binding protein 3. I agree that the patient seems to have constitutional delay of growth and familial short stature and that no intervention is needed. Children with these conditions have normal growth velocities and achieve a normal adult height with respect to that of their family.2 The diagnosis of idiopathic short stature is not intended to include "normal-variant short stature." Growth rates that were less than the 50th percentile for age were part of the definition of idiopathic short stature in an early report on the effect of growth hormone treatment.3 Significantly short children who grow inadequately for reasons we have not yet identified are considered to have idiopathic short stature and may require growth-promoting interventions.
Lee gives too much support to interpretations of bone age and height predictions, the accuracy and reliability of which have recently been questioned.4,5 The identification of children with pathologic growth failure who need further diagnostic and therapeutic interventions remains a challenge.
Robert Rapaport, M.D.
Mount Sinai School of Medicine
New York, NY 10029
robert.rapaport@msnyuhealth.org
References
Lee MM. Idiopathic short stature. N Engl J Med 2006;354:2576-2582.
Rapaport R, Bowlby DA. Clinical aspects of growth disorders. In: Pescowitz OH, Eugster EA, eds. Pediatric endocrinology: mechanisms and management. Philadelphia: Lippincott Williams & Wilkins, 2004.
Hintz RL, Attie KM, Baptista J, Roche A. Effect of growth hormone treatment on adult height of children with idiopathic short stature. N Engl J Med 1999;340:502-507.
Krajewska-Siuda E, Malecka-Tendera E, Krajewski-Siuda K. Are short boys with constitutional delay of growth and puberty candidates for rGH therapy according to FDA recommendations? Horm Res 2006;65:192-196.
Rapaport R. Adult height predictions for constitutional growth delay, growth hormone treatment for idiopathic short stature and the FDA: are they related? Horm Res 2006;65:197-199.
The author replies: The vignette was intentionally brief, as is consistent with the format of Clinical Practice articles. Implicit in the statement that the "evaluation reveals no systemic disease" is that the results of laboratory studies (including measurements of insulin-like growth factor I and insulin-like growth factor–binding protein 3) were normal. Although growth velocity is a key component of growth assessment, the growth rate of a 12-year-old child with idiopathic short stature can be indistinguishable from that of a child of the same age with constitutional delay of growth and development. Moreover, the unreliability of measurements of height velocity for the assessment of growth and the poor correlation between two serial 12-month values for growth velocity in a given child have been reported.1 Although prediction of adult height is imprecise,2,3 the indications of the Food and Drug Administration for the use of growth hormone in idiopathic short stature specifically state that "an adult height within the normal range is unlikely to be attained." Although I am uncertain that growth velocity is a better basis than height prediction for deciding which children will benefit from growth hormone therapy, I agree with Rapaport that our inability to predict adult height accurately and to identify children with pathologic growth poses diagnostic and therapeutic challenges.
Mary M. Lee, M.D.
University of Massachusetts Medical School
Worcester, MA 01655
mary.lee@umassmed.edu
References
Voss LD, Wilkin TJ, Bailey BJR, Betts PR. The reliability of height and height velocity in the assessment of growth (the Wessex Growth Study). Arch Dis Child 1991;66:833-837.
Krajewska-Siuda E, Malecka-Tendera E, Krajewski-Siuda K. Are short boys with constitutional delay of growth and puberty candidates for rGH therapy according to FDA recommendations? Horm Res 2006;65:192-196.
Bramswig JH, Fasse M, Holthoff ML, von Lengerke HJ, von Petrykowski W, Schellong G. Adult height in boys and girls with untreated short stature and constitutional delay of growth and puberty: accuracy of five different methods of height prediction. J Pediatr 1990;117:886-891.
Lee gives too much support to interpretations of bone age and height predictions, the accuracy and reliability of which have recently been questioned.4,5 The identification of children with pathologic growth failure who need further diagnostic and therapeutic interventions remains a challenge.
Robert Rapaport, M.D.
Mount Sinai School of Medicine
New York, NY 10029
robert.rapaport@msnyuhealth.org
References
Lee MM. Idiopathic short stature. N Engl J Med 2006;354:2576-2582.
Rapaport R, Bowlby DA. Clinical aspects of growth disorders. In: Pescowitz OH, Eugster EA, eds. Pediatric endocrinology: mechanisms and management. Philadelphia: Lippincott Williams & Wilkins, 2004.
Hintz RL, Attie KM, Baptista J, Roche A. Effect of growth hormone treatment on adult height of children with idiopathic short stature. N Engl J Med 1999;340:502-507.
Krajewska-Siuda E, Malecka-Tendera E, Krajewski-Siuda K. Are short boys with constitutional delay of growth and puberty candidates for rGH therapy according to FDA recommendations? Horm Res 2006;65:192-196.
Rapaport R. Adult height predictions for constitutional growth delay, growth hormone treatment for idiopathic short stature and the FDA: are they related? Horm Res 2006;65:197-199.
The author replies: The vignette was intentionally brief, as is consistent with the format of Clinical Practice articles. Implicit in the statement that the "evaluation reveals no systemic disease" is that the results of laboratory studies (including measurements of insulin-like growth factor I and insulin-like growth factor–binding protein 3) were normal. Although growth velocity is a key component of growth assessment, the growth rate of a 12-year-old child with idiopathic short stature can be indistinguishable from that of a child of the same age with constitutional delay of growth and development. Moreover, the unreliability of measurements of height velocity for the assessment of growth and the poor correlation between two serial 12-month values for growth velocity in a given child have been reported.1 Although prediction of adult height is imprecise,2,3 the indications of the Food and Drug Administration for the use of growth hormone in idiopathic short stature specifically state that "an adult height within the normal range is unlikely to be attained." Although I am uncertain that growth velocity is a better basis than height prediction for deciding which children will benefit from growth hormone therapy, I agree with Rapaport that our inability to predict adult height accurately and to identify children with pathologic growth poses diagnostic and therapeutic challenges.
Mary M. Lee, M.D.
University of Massachusetts Medical School
Worcester, MA 01655
mary.lee@umassmed.edu
References
Voss LD, Wilkin TJ, Bailey BJR, Betts PR. The reliability of height and height velocity in the assessment of growth (the Wessex Growth Study). Arch Dis Child 1991;66:833-837.
Krajewska-Siuda E, Malecka-Tendera E, Krajewski-Siuda K. Are short boys with constitutional delay of growth and puberty candidates for rGH therapy according to FDA recommendations? Horm Res 2006;65:192-196.
Bramswig JH, Fasse M, Holthoff ML, von Lengerke HJ, von Petrykowski W, Schellong G. Adult height in boys and girls with untreated short stature and constitutional delay of growth and puberty: accuracy of five different methods of height prediction. J Pediatr 1990;117:886-891.