Timing of Puberty, Pubertal Growth, and Adult Height in Short Children Born Small for Gestational Age Treated With Growth Hormone

Growth Hormone Treatment for Non-GHD Disorders: Excitement Tempered by Biology

The success of growth hormone (GH) replacement in children with classical GH deficiency has led to excitement that other causes of short stature may benefit similarly. However, clinical experience has shown less consistent and generally less dramatic effects on adult height, perhaps not surprising in light of increased understanding of GH and growth plate biology. Nonetheless, clinical demand for GH treatment continues to grow. Upon the 20th anniversary of the US Food and Drug Administration's approval of GH treatment for idiopathic short stature, this review will consider the factors underlying the expansion of GH treatment, the biological mechanisms of GH action, the non-GH-deficient uses of GH as a height-promoting agent, biological constraints to GH action, and future directions.

Early Growth Hormone Initiation Leads to Favorable Long-Term Growth Outcomes in Children Born Small for Gestational Age

CONTEXT

Early initiation of growth hormone (GH) therapy is recommended for short children born small for gestational age (SGA); however, real-world data indicate that treatment is often delayed.

OBJECTIVE

To assess the impact of patient age at GH therapy initiation on long-term growth outcomes and safety in short children born SGA.

METHODS

Analysis of pooled data from NordiNet® International Outcome Study (NCT00960128; 469 European clinics) and the ANSWER Program (NCT01009905; 207 US clinics), two large, complementary observational studies. Patients received GH as prescribed by their treating physician. Enrolled patients born SGA were categorized into three groups based on their age at GH treatment initiation: 2-<4 years, 4-<6 years, and ≥6 years. Patient characteristics at birth and GH initiation, auxology, and safety data were evaluated.

RESULTS

The effectiveness analysis (treatment-naïve and prepubertal patients at GH initiation) included 3,318 patients: 10.7% aged 2-<4 years at therapy initiation, 31.6% aged 4-<6 years, and 57.7% aged ≥6 years. Following 8 years of therapy, the mean improvement in height standard deviation score from baseline was significantly greater in the 2-<4 years group vs the 4-<6 years (+2.5 vs +2.2; P = 0.0054) and ≥6 years groups (+2.5 vs +1.7; P < 0.0001). No unexpected safety events were reported.

CONCLUSION

Early initiation of GH therapy in short children born SGA may be an important contributor to height optimization. The data are reassuring regarding the long-term safety of GH therapy in this population.