Exacerbation of BMI after cessation of growth hormone therapy in patients with Prader-Willi syndrome.

Long-term treatment with growth hormone (GH) in patients with Prader-Willi syndrome (PWS) improves not only height velocity, height standard deviation score, and final height, but also the degree of obesity and body composition abnormalities. Anecdotally, PWS patients tend to suffer from severe obesity and its complications after cessation of GH therapy. However, there have been no studies to investigate changes in body mass index (BMI) and adipose tissue distribution after cessation of GH therapy in young PWS patients. Therefore, we investigated changes in the BMI-standard deviation score (SDS) and adipose tissue distribution after cessation of GH therapy in PWS patients. We evaluated 14 PWS patients. BMI-SDS was calculated at 0, 6, 12, 18, and 24 months before and after cessation of GH treatment. We also evaluated subcutaneous adipose tissue (SAT) (cm(2)) and visceral adipose tissue (VAT) (cm(2)) area in 8 of the 14 study patients with single slice abdominal computed tomography at the level of the umbilicus. The BMI-SDS significantly increased at 6, 12, 18, and 24 months after cessation of GH therapy (P = 0.039, P = 0.008, P = 0.003, P = 0.003, respectively). There was a tendency toward increases in VAT at 12 and 24 months after cessation of GH therapy, but the increases did not reach statistical significance (P = 0.062, P = 0.125, respectively). Therefore, cessation of GH therapy in PWS patients worsened BMI. To maintain good body composition and prevent complications of obesity, long-term use of GH in adult PWS patients may be advisable.