Clinical Aspects of Growth Hormone Deficiency in Adults

I. Introduction

GRADUALLY it is being realized that GH may have important physiological functions in adult man. Until recently, GH was only used to treat short statured children with established GH deficiency (GHD), and it remains common practice to discontinue GH replacement therapy when final height is reached. From a physiological point of view, it is questionable whether this approach is appropriate since it is well known that GH secretion persists throughout life (1–5). Daily GH production reaches its maximum during puberty (3–5). Thereafter, the GH secretion rate gradually decreases with age (3).

Recently, several studies have shown that GHD in adults is associated with abnormalities in body composition (6–14), metabolic derangements (15–17), and suboptimal physical performance (18–20). Since recombinant technology has solved the limitations in GH supply, policies concerning GH replacement therapy in man may now be reconsidered. The studies performed in GHD adults uniformly suggest that these patients benefit from GH replacement therapy (19–34). However, it has also become clear that GH substitution is not without side effects. The purpose of this review is to describe and analyze the reported findings in untreated GHD adults as well as to evaluate the effects and side effects of GH replacement therapy. The pharmacological aspects of GH treatment in GHD subjects have been addressed recently (35).