Growth hormone therapy in childhood-onset growth hormone deficiency - Adult anthropometric and psychological outcomes

The current adult heights of hypopituitary children treated with recombinan t human growth hormone (rGH) now range between -1.5 and -0.7 height standar d deviations (Ht SDS) of control populations. These height outcomes are mar kedly better than the ones observed following treatment with pituitary-deri ved human growth hormone (pGH) (between -4.7 and 2.0 Ht SDS). Although trea tment with rGH has not yielded adult heights that are equal to genetic targ et heights, the discrepancy is much less now than in previous decades. High er rGH dose, longer duration of treatment, early age at diagnosis, correcti on of height deficit prior to onset of puberty, and daily rGH injections ha ve had beneficial effects on final adult heights. The current dosing regime ns (0.3-0.18 mg/kg/wk) have not had an adverse effect on bone maturation an d have not stimulated an earlier onset of puberty. Although height gains in puberty are less than controls, a majority of treated subjects reach heigh ts within the normal range for adults. Higher doses of rGH during puberty h ave been studied in limited numbers of adolescents with positive effects; h owever, standard dosing wilt likely continue to be used because of financia l considerations and safety concerns. Further improvements in adult heights are likely to be reported when the youngest children who began rGH in 1985 complete their growth. Several studies have investigated the quality of life (QOL) of GH-deficient (GHD) patients who, as children, had been treated with GH predominantly du ring the pGH era. Domains of functioning assessed include educational attai nment, employment, and marital status. Although some studies have reported a generally positive adaptation, others have shown this group to exhibit ma rked deficits. Limited adult height outcomes in the pGH era of GH therapy h as sometimes been used to account for poor outcomes. Variable behavioral fi ndings are likely related to sample heterogeneity and disparate research me thodologies and designs, most particularly the choice of control or compari son groups. In addition to summarizing this older literature, we report on a recently completed investigation in which the QOL adjustment of GHD patie nts is compared to that of same-sex siblings. Comparisons between GHD cases and norms for standardized questionnaires indicated both better and worse functioning in several domains. In contrast, very limited differences were detected between GHD cases and same-sex siblings. IGHD (isolated growth hor mone deficiency) patients were functioning better than those with MPHD (mul tiple pituitary hormone deficiencies), but the effect sizes of these differ ences in most areas were relatively small. Adult height and degree of growt h over the course of GH therapy were generally unrelated to QOL outcomes. F indings from the present study underscore the importance of selecting unbia sed control/comparison groups in evaluating psychological outcomes among GH D adults.