Characteristics of adults who wish to enter a trial of growth hormone replacement

It is possible that the degree of perceived well-being may influence the decision of an adult with GH deficiency to receive GH replacement. We have therefore sought factors which influenced whether or not such a patient wished to enter a study of GH replacement.

Biochemical, anthropometric and demographic characteristics, and well-being, of patients who chose to enter a 12-month study of GH replacement at Christie Hospital NHS Trust were compared with those of patients who declined to enter the study.

Sixty-five adults with GH deficiency who entered a study of GH replacement and 33 adults with GH deficiency who were approached but who declined to enter the study.

The two groups of patients were compared according to sex, age, height, weight, body mass index, peak serum GH response to provocative testing, estimated duration of GH deficiency, whether GH deficiency was of childhood or adult onset, presence or absence of additional pituitary hormone deficiencies, aetiology of GH deficiency, previous therapeutic interventions, employment status, marital status and living arrangement (65 entered vs 33 declined to enter). Well-being or distress was measured using the Nottingham Health Profile (NHP) (65 entered vs 20 declined to enter) and the Psychological General Well-being Schedule (PGWBS) (33 entered vs 19 declined to enter).

Those who entered the study had significantly higher scores on the energy (P = 0.03) and emotional reaction (P = 0.02) subsections and on the total score (P = 0.04) of the NHP, indicating greater distress, and had a significantly lower score (P = 0.009) on the vitality subsection of the PGWBS, again indicating greater distress. Those who entered the study had a significantly lower prevalence of non-functioning pituitary adenoma (P = 0.02) but there was no other difference in biochemical, anthropometric or demographic characteristics between the two groups.

Adults who enter a study of GH replacement exhibit greater distress on questionnaire assessment than those who decline to enter such a study. This bias must be considered when interpreting studies of the effect of GH replacement on well-being in adults.