Gender of pediatric recombinant human growth hormone recipients in the United States and globally.

BACKGROUND: Gender disparities were found in reports of early pediatric recombinant human GH (rhGH) use in the United States. With rhGH entering its third decade, we sought to examine U.S. gender-based treatment patterns and how these patterns compare with that of other countries.

METHODS: All children entered in the Pfizer International Growth Study, a database designed to document long-term outcomes and safety of Genotropin (Pfizer, New York, NY), were categorized by gender, location, date and age of therapy initiation, and diagnosis. Measures of national health status, health care expenditure, general economic indices, and mean adult heights were also compared.

RESULTS: Throughout the past 20 yr, the United States had an almost 2:1 male to female ratio overall. The gender ratio depended on the specific indication and age. There was no consistent relation to geographical region, pediatric population size, or density of pediatric endocrinologists. Male predominance was seen in Asia (mostly Japan), the United States, and Europe/Australia/New Zealand (65, 64, and 55%, respectively), but not the rest of the world (47%), where rhGH was prescribed less frequently. In the countries with the greatest rhGH use, the gender ratios depended on the specific indications but did not correlate with mean adult height, national health care measures, or general economic indices.

CONCLUSIONS: Male predominance among U.S. pediatric rhGH recipients persists, especially for indications without a clear organic etiology. Global differences in gender ratios suggest that factors other than biology are at play. We speculate that social and cultural pressures and the health care systems' permissiveness toward paying for rhGH therapy contribute to these international differences.