PWS doctors skip sleep studies for early growth hormone therapy
Study uncovers gaps between real-world practice, care guidelines
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An international survey found that clinicians with the most experience caring for infants with Prader-Willi syndrome (PWS) are more likely to forgo a sleep study before starting growth hormone therapy — contrary to current guidelines.
For U.S. doctors, the most commonly cited reason was avoiding a delay in treatment with growth hormone — also known as somatropin (sold as Genotropin and Norditropin, with biosimilars available) — while for those outside the U.S., it was a lack of a pediatric sleep laboratory.
“These findings highlight a gap between current guideline recommendations which encourage [sleep study] prior to [growth hormone therapy] initiation and real‐world clinical practice,” the researchers wrote. Most clinicians favor updating the guidelines, they added.
The study, “International Survey of Growth Hormone and Sleep Evaluation Practices in Infants With Prader-Willi Syndrome,” was published in Clinical Endocrinology.
Early treatment has benefits
PWS is a rare genetic condition typically characterized by slow growth, intellectual disability, insatiable hunger, and behavioral problems. Most PWS patients have deficient levels of growth hormones, which regulate biological processes including growth and body composition.
Growth hormone therapy is a standard PWS treatment. In addition to benefits for growth rate and body composition, this therapy, when started early, may also promote motor and cognitive development.
Current guidelines recommend an overnight sleep study, called a polysomnogram (PSG), before starting growth hormone therapy. The goal is to address concerns about how the hormone therapy may affect abnormal breathing during sleep, a common PWS symptom in infants.
Yet conducting sleep studies in infants is difficult: Pediatric sleep laboratories are scarce, and there are no standard definitions of normal sleep patterns in infancy. Because PWS can now be diagnosed in newborns using genetic testing, doctors must balance the need for a sleep assessment against delaying growth hormone therapy.
To understand how clinicians approach this decision, a team of researchers in the U.S. conducted a survey across 18 countries. Their goal was to determine whether an initial (baseline) PSG was always obtained before starting hormone therapy in PWS infants younger than 1.
Most (78.7%) of the 141 completed surveys came from clinicians practicing in the U.S., and more than half (60.3%) had 10 or more years of experience caring for people with PWS. The researchers grouped clinicians by the number of PWS patients seen per year: high volume (21 or more), medium (five to 20), and low volume (fewer than five).
Overall, the results showed a link between a higher patient volume and a lower likelihood of prescribing a PSG prior to growth hormone therapy. Specifically, more than half (56.1%) of the high-volume respondents said that they “not always” did so, while most respondents in the medium-volume (69%) and low-volume (74.1%) replied they did so.
Further statistical analyses showed that high-volume respondents were significantly more likely, by more than 3.5 times, to answer “not always” than low-volume respondents. Geographic location and years of experience were not tied to the likelihood of prescribing a PSG before growth hormone therapy.
Avoiding a delay in the start of growth hormone therapy and being less concerned about growth hormone side effects, such as apnea (breathing pauses) or sudden death, were the most commonly cited reasons for not always prescribing a PSG first in the high-volume group. Lack of PSG availability was the most commonly cited reason in the low-volume group.
High-volume respondents reported a significantly lower median ideal age to start growth hormone therapy than the other two groups (4 vs. 6 months). And, significantly more clinicians in the high-volume group (61%) prescribed hormone therapy in the neonatal intensive care unit (NICU) before discharge than in the medium- (35%) and low-volume (25%) groups.
The proportion answering “not always” to an early PSG was similar for clinicians inside and outside the U.S. (38% vs. 31%).
Still, the reasons differed. In the U.S., the most common reason was avoiding a growth hormone therapy delay (56.1%). Outside the U.S., the most common reason was the lack of a sleep laboratory (77.8%). Respondents in the U.S. were also significantly more likely to report fewer concerns about side effects in infants than outside the U.S. (53.7% vs. 11.1%).
The most frequently selected age range for starting hormone therapy was lower inside the U.S. (2-6 months vs. 6 to 12 months), but this difference was not statistically significant, meaning it could be due to chance. More than twice as many clinicians in the U.S. started hormone therapy in infants in the NICU as outside the U.S. (43.3% vs. 18.5%).
Most respondents (72%) supported updating the PWS consensus guidelines.
“High volume PWS clinicians were more likely to report not always obtaining baseline PSG prior to starting GH in infants, primarily to prevent delayed therapy,” the researchers wrote. “These findings highlight a gap between guidelines and practice and support the need for … outcome data [collected over time].”
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