Improved Height, Body Composition Found in PWS Patients Treated With Growth Hormone

Growth hormone therapy improves height and body composition while lowering body mass index (BMI) in people with Prader-Willi syndrome (PWS), according to a review of clinical trials.

The study, “Growth hormone treatment in Prader-Willi syndrome patients: systematic review and meta-analysis, was published in the journal BMJ Paediatrics Open. 

PWS is characterized by physical, behavioral, and intellectual impairment. Affected individuals develop an insatiable appetite, leading to overeating and obesity. 

A deficiency in growth hormone is common in PWS patients and can result in a short stature from the second decade of life. 

Treatment with recombinant human growth hormone (rhGH) is currently recommended for PWS patients with and without growth hormone deficiency to help improve stature, metabolism, and weight gain. Previous studies indicated that rhGH may improve cognitive function, language, motor development and behaviors of people with PWS.

So far, several clinical trials evaluating the impact of rhGH in PWS have been performed in infants, children, and adolescents. 

To provide a summary of the current knowledge of rhGH therapy and to provide recommendations for future clinical practice and research, a review of such studies was conducted by investigators at the Universidade de Sao Paulo in Brazil, in collaboration with researchers at the Université Paris Descartes, in France. 

The team searched medical databases for PWS patients, with or without growth hormone deficiency, who had participated in clinical trials that included a control group. 

The primary goal was to assess the impact of rhGH on growth, BMI, body composition, and cognitive function. Additional goals included changes in head circumference, muscle strength, behavior, and side effects.

In total, the online search yielded 16 randomized and 20 non-randomized trials. In a randomized study, participants are assigned randomly to a group, such as treatment with growth hormone or no treatment. The opposite is seen in non-randomized studies, as investigators decide which group each participants is allocated. 

Among the identified studies, the scientists analyzed nine randomized trials that included a total of 328 patients. Compared to the untreated control group, patients on rhGH grew taller, especially if starting treatment after 3.5 years of age. Non-randomized studies also showed improved stature with rhGH. but the analysis was based on low quality evidence from the original studies, the scientists said.

In addition, three randomized trials showed that growth velocity was significantly increased while BMI was reduced in treated patients. Non-randomized trials showed no difference in BMI after rhGH treatment. Notably, no change in BMI during follow-up was “the opposite of the disease natural history,” the scientists wrote, but the quality of evidence was very low, they said.

Among 204 patients from six randomized studies, as well as non-randomized trials with follow-up, treatment with rhGH led to a significant reduction in fat mass proportion. Meanwhile, lean mass increased in two randomized trials comparing treatment with the control group.

rhGH treatment also increased head circumference by 0.55 cm compared to no treatment in three randomized studies with 114 patients. 

Cognitive function was not assessed because the studies were not comparable. Also, the impact of rhGH treatment on behavior was not clear as most studies did not show differences.

While there were few reported side effects in randomized studies, non-randomized trials with longer follow-up identified sleep apnea, headache, type 2 diabetes, and swelling. Scoliosis, or sideways spine curvature, also was reported, but “it is difficult to establish a relationship between its rhGH progression and treatment,” the investigators wrote.

“Based on high quality evidence, rhGH treatment favoured an improvement of stature, body composition and body mass index, modifying the disease’s natural history,” they added.