PREDICTIVE FACTORS IN THE DETERMINATION OF FINAL HEIGHT IN BOYS WITH CONSTITUTIONAL DELAY OF GROWTH AND PUBERTY

Seventy-eight patients who had constitutional delay of growth and pube rty were included in a retrospective study to determine whether, at th e time of first evaluation, any predictive features could suggest fina l height outcome. Mean chronologic age was 14.3 years (range, 12 to 18 years), and all were either prepubertal or in an early stage of puber tal maturation (4 ml testicular volume). Initial mean (+/- SD) height standard deviation score was -2.74(+/- 0.71); 85% had a relatively sho rt spine compared with subischial leg length. Mean (+/- SD) growth rat e was 4.8 (+/- 1.6) cm/year, and epiphyseal maturation was delayed by 2.4 (+/- 1) years. Sixteen boys were treated with a sustained-action p reparation of testosterone' (50 mg monthly for 3 to 4 months), six wit h oxandrolone (1.25 mg daily for a mean of 4 months), and one with bot h drugs in sequence. At final height attainment, 58% of the boys faile d to achieve their full genetic potential; among the remaining 42%, on ly 0.7% attained a final height above corrected mid-parental height. T he relative disproportion between the segments had no significant chan ge at final height attainment. Regression analysis showed that final h eight impairment (the difference between mid-parental height and final height) was negatively influenced by standing height and growth veloc ity when initially evaluated and positively by the degree of segmental body proportion; that is, patients who were taller, were growing at a faster rate, and who had a major degree of segmental body disproporti on with a short spine and long leg length attained a final height clos er to their mid-parental height, irrespective of the degree of delayed epiphyseal maturation. Neither testosterone nor oxandrolone administe red during early puberty modified final height attainment or segmental proportion. We conclude that a late onset in the timing of puberty se ems to be deleterious to spinal growth and consequently to final heigh t attainment. An alternative diagnosis should be sought among patients with features of constitutional delay of growth and puberty who do no t have a significant degree of body disproportion. In these patients, as well as in those who are extremely short, who have a poor growth ra te, or who have an unfavorable genetic potential, an alternative thera peutic approach may be required.