Respiratory function in adults with growth hormone deficiency: Effects of 1 year of treatment

The aim of the present study was to evaluate lung volume and respiratory muscle strength in patients with growth hormone deficiency (GHD) before and after 6 and 12 months of GH treatment. Respiratory pressure, lung volume and diffusion capacity were measured in ten patients with childhood-onset GHD, in ten patients with adult-onset GHD and in ten healthy controls. Patients with childhood-onset GHD had significantly lower maximal inspiratory and expiratory pressures than the controls. Total lung capacity, vital capacity and functional residual capacity were also significantly lower than in the healthy controls, while the residual volume and diffusion capacity of the lungs did not show any significant change. Patients with adultonset GHD exhibited a significant reduction in maximal expiratory pressure only, compared with the controls. After 6 months of GH treatment, no significant differences were found in any of the evaluated parameters. After 12 months of GH treatment, patients with childhood-onset GHD showed significant improvements in lung volumes and maximal respiratory pressures, and those with adult-onset GHD showed a significant improvement in maximal expiratory pressure. The results of this study show that adult patients affected with childhood-onset GHD suffer from impaired ventilatory function, probably due to a reduction of lung size and respiratory muscle strength. This impairment was fully restored after 1 year of GH treatment. In addition, patients with adult-onset GHD exhibited impaired maximal expiratory pressure, which was also probably due to respiratory muscle weakness; this was significantly improved after 1 year of GH therapy.