The effect of long-term untreated growth hormone deficiency (GHD) and 9 years of GH replacement on the quality of life (QoL) of GH-deficient adults.

BACKGROUND

Quality of life (QoL) is reduced in GH-deficient adults compared with the normal population. Further support for the role of GH in the maintenance of QoL is derived from short-term studies of GH replacement in severely GH-deficient adults; these have predominantly reported beneficial effects, although the degree of improvement has often been modest. To date, however, there are few data to demonstrate whether this beneficial effect on QoL is maintained in the long term.

PATIENTS AND METHODS

This study consisted of the follow-up of 85 GH-deficient adults who completed the Nottingham Health Profile (NHP) and the Psychological General Well-Being Schedule (PGWB) self-rating questionnaires in 1992, as part of a 12-month double-blind randomized study of GH replacement. In 2001 we attempted to contact all 85 patients and asked them to complete the two questionnaires again. Follow-up data were obtained in 61 patients. The findings were analysed according to whether the individual had received GH continuously since completion of the initial study, received no further GH replacement, or received GH replacement for only part of the intervening time. Both the NHP and the PGWB give a total score and subsection scores for six specific areas of QoL. A high score correlates with increased morbidity in the NHP, and with reduced morbidity in the PGWB.

RESULTS

Fifty-nine patients completed the NHP at both time points. The patients who continued GH (n = 17) had significantly greater morbidity at baseline than patients who opted to discontinue therapy (n = 27), as reflected by the higher scores overall (5.7 +/- 4.0 vs. 2.8 +/- 3.5; P = 0.01) and in the energy subsection (47.0 +/- 34.7 vs. 13.2 +/- 28.6; P < 0.001). Over the study period energy levels improved in the patients who remained on GH therapy (47.0 +/- 34.7 vs. 25.7 +/- 31.0; P = 0.04). By contrast, a deterioration in the physical mobility subsection (2.4 +/- 5.4 vs. 8.2 +/- 16.7; P = 0.04) occurred in the patients who did not continue GH therapy, and no change occurred in the energy subsection. In the 36 patients who completed the PGWB significant differences were observed at baseline between patients who received GH replacement continuously (n = 10) and those who discontinued therapy (n = 21) in the overall score (67.2 +/- 14.1 vs. 86.8 +/- 14.7; P = 0.001); and in the subsections for anxiety (P = 0.04), depression (P = 0.04), well-being (P = 0.001), self-control (P = 0.04) and vitality (P < 0.001); the greater morbidity at baseline being observed in the patients who continued GH replacement. In the patients receiving GH continuously for 9 years the vitality subsection score improved significantly (7.7 +/- 2.4 vs. 12.5 +/- 3.2; P = 0.003), whereas no change in vitality score occurred in patients who did not continue GH therapy. The change in the energy subsection of the NHP and vitality subsection of the PGWB over the 9 years of the study were significantly different between the patients who opted to continue GH replacement and those who discontinued therapy (P = 0.008 and P < 0.001, respectively).

CONCLUSION

During this 9-year study, small but significant declines in health were observed in GH-deficient adults who remained untreated. By contrast, the patients who received GH continuously experienced improvements in energy levels while all other areas of QoL were maintained. The beneficial effects of GH on QoL are therefore maintained with long-term GH replacement and obviate the reduction in QoL seen over time in untreated GH-deficient adults.