Controversy about Treatment of Growth Hormone–Deficient Adults: A Commentary

Growth hormone deficiency was first described in children with growth retardation, and for three decades, the therapeutic use of growth hormone was restricted to promoting linear growth. Two developments—the appearance of Creutzfeldt–Jakob disease and the availability of recombinant human growth hormone—ended the use of human pituitary-derived growth hormone therapy and opened the possibility of using growth hormone in growth hormone–deficient adults. For the past 13 years, such use has been a reality. As with many other areas of medicine, the introduction of a new therapy is associated with initial excitement, followed by a period of careful analysis of the results of therapy and, not infrequently, a degree of controversy about its benefits. Growth hormone is no exception to this paradigm, and the salient points of growth hormone replacement in adults have been reviewed by several authors (1-3). In addition, the specificity of the manifestations of the disorder to which therapy is directed—adult growth hormone deficiency—has been questioned.

In this issue, Dr. Cook (4) and Dr. Isley (5) provide strong arguments for diametrically opposed positions concerning growth hormone treatment for adult growth hormone deficiency. For readers already convinced of the validity of either argument, the discussion that follows may not be of particular relevance. However, for those searching for a position between the two extremes, I will attempt to offer a rationale for a “middle ground.”

The controversy is based on many issues. First, physicians do not agree on whether the manifestations of adult growth hormone deficiency constitute a specific disease entity. Second, there are differing degrees of growth hormone deficiency (partial vs. total) and a plethora of proposed diagnostic criteria. Third, many of the long-term risks of growth hormone deficiency (most important, effects on life expectancy) are uncertain. Finally, agreement on the end points of therapy (intermediate vs. late …