Increased availability of human growth hormone. A challenge for health economics

Growth hormone therapy and quality of life in adults and children

A fundamental goal of growth hormone (GH) treatment for both adults and children is improvement in quality of life (QOL). Assessments of the therapeutic role of GH depend on its effectiveness in meeting this and other goals (including improved metabolic status in adults and improved growth in children) in relation to economic parameters. However, there are difficulties in interpreting data on GH treatment and QOL. These include controversy about appropriate definitions and measures for assessing QOL, disease adaptation, comorbid conditions, and potential patient selection bias. In GH-deficient adults who have completed linear growth, there is considerable evidence that GH exerts effects on body composition, serum lipids, and bone and mineral density. Several controlled trials have also examined the effect of GH treatment on QOL in GH-deficient adults. They generally indicate improvement in QOL with GH treatment, although there are inconsistencies in the data. Caveats include differing outcome measures and instruments, instruments that are not disease specific, variation in characteristics of patient samples and treatment protocols, evidence of a placebo effect, and some inconsistency among results. Open-label trials in adults also suggest improvement in QOL with GH treatment, although interpretation is limited by potential placebo effects and patient self-selection. Studies in children have generally addressed psychological status, and relatively few specifically focus on QOL. In children with classical GH deficiency, it is intuitive that GH treatment will improve QOL, although hard data are lacking. In children with idiopathic short stature, evidence for improved QOL as a result of GH treatment is not well developed. Translating changes in QOL, together with physiological and metabolic benefits, into economic cost-benefit or cost-effectiveness analyses are needed. In doing so, it will be important to consider subgroups of patients who may derive differential benefit from GH treatment. These analyses are central to the development of a framework for research, decision making, and policy for GH treatment.

Prediction of the growth response of short prepubertal children treated with growth hormone. Swedish Paediatric Study Group for GH treatment

The aim of this study was to identify predictors of the growth response to growth hormone (GH) during the first 2 years of GH treatment, using auxological data and the maximum GH response (GHmax) to provocation tests. The patients were 169 prepubertal short children (27F, 142M), with Gmax values ranging from 0 to 65 mU/l. Their mean age (+/- SD) was 8.3 +/- 2.4 years (range 3-13 years), mean height SDS -3.0 +/- 0.7 (range -1.5 to -6.0 SDS) and mean pretreatment height velocity was normal (+/- 0.0 SDS) (range -1.6 to +0.9 SDS). The increase in height SDS during the first 2 years of GH treatment (0.1 U/kg/day) varied from 0.10 to 3.75 SDS, with younger children having a better growth response. Individual growth responses correlated (p < 0.001) with GHmax (r = -0.37), age (r = -0.35), 1-year pretreatment delta SDS (r = -0.25), mid-parental height SDS (r = 0.34), height SDS at start of treatment (r = -0.22) and difference between height SDS of an individual child at the onset of GH treatment and mid-parental height expressed in SDS (diff SDS) (r = -0.43). In a multiple stepwise linear regression model, diff SDS and log GHmax were found to be the strongest predictors of the magnitude of the growth response. In the short children in this study who exhibited a broad range of GHmax values, 33% of the growth response during the first 2 years of treatment could be predicted.