Sleep Issues Common, Rarely Addressed, White Paper Asserts

People with Prader-Willi syndrome (PWS) and other diseases commonly experience sleep problems, and the problems are rarely addressed effectively by healthcare professionals, according to a white paper published by Harmony Biosciences.

Excessive daytime sleepiness, or EDS, is a common symptom experienced by people with rare diseases like PWS. Data indicate that nearly four in five children with neurodevelopmental disorders experience issues with sleep, as compared to 25% in the general population. However, sleepiness is rarely studied in these rare disorders.

A group of patient advocates representing a variety of rare diseases met in December last year, with the aim of discussing sleep problems across diseases. The group included representatives from two PWS-specific organizations, Prader-Willi Syndrome Association USA and the Foundation for Prader-Willi Research (FPWR).

The discussions revealed several general themes, which were detailed in the white paper.

One theme that emerged is that EDS is commonly reported in many different diseases. However, there is little published data about links and the severity of sleep disturbances in such cases, so most of the evidence comes from anecdotal reports. In contrast, the impact of sleep problems is well known in narcolepsy, a condition defined by extreme daytime sleepiness.

“Research into addressing EDS beyond the narcolepsy community —particularly in rare diseases — is woefully inadequate,” according to the white paper.

The paper stresses that a lack of proper sleep can have substantial and wide-ranging effects. Inadequate sleep is linked to a variety of health conditions (e.g., diabetes and stroke) and with poorer cognition. Being sleepy during the day also can make it harder to effectively engage at school or at work, and it can complicate a person’s social life.

According to the paper, the extent and severity of the impact of EDS is not clear because it has not been well-studied. However, there is a theoretical basis for supposing that disrupted sleep could affect symptoms in conditions such as PWS. Specifically, PWS is characterized by abnormal hunger, and there is ample data showing a link between sleep and eating.

“The general connection between sleep and eating is well known, with researchers describing links between sleep cycles and the body’s ability to process food, the role of sleepiness in maintaining dietary discipline, and impulse to eat that is driven by tiredness rather than actual hunger. Further, EDS and short sleep duration correlate with obesity, regardless of diet and exercise,” according to the paper.

The paper also notes that sleep disruption could worsen behavioral problems in PWS and other conditions.

Despite the negative impact poor sleep can have, sleep issues are rarely addressed in treatment guidelines, according to the paper. That makes it difficult for patients and their families to obtain needed support. The paper also stresses that, in many cases, people living with rare diseases already have a lot to deal with, which can make it hard to find the time and energy to address EDS, especially when it is not viewed as a major problem (compared to other aspects of a disease).

Another theme discussed in the paper is that people with rare diseases often find it hard to get those in the medical community to take their sleep problems seriously. This can be a problem particularly in the U.S., where sleep often is not valued as the health necessity that it is.

“Patients for whom EDS is a secondary, less well-known, aspect of their disease face even more difficulty in being treated seriously, perhaps due, in part, to the difficulty of measuring sleep in these populations,” the paper states.

Broadly, the paper calls for more research into the effects of sleep problems and EDS in rare diseases. It notes, however, that measuring sleep quality in rare diseases can be challenging; as such, there is a need for better methods to facilitate this kind of research. Some suggested methods include survey instruments and apps to collect patient-reported data.

The paper also calls more generally for increased awareness of how sleepiness can affect people with rare conditions.

“We want to help raise awareness of how excessive sleepiness is prevalent across the spectrum of rare disease,” Cate McCanless, senior vice president of Corporate Affairs & Policy at Harmony Biosciences, said on the FPWR website. “EDS is much more closely associated with rare sleep disorders, like narcolepsy, but it can pose significant physical, emotional, social, and cognitive challenges for so many others with rare disorders who may not even realize it.”

Harmony recently launched a clinical trial (NCT04257929) to test pitolisant as a treatment for EDS in people with PWS. The trial is still recruiting. Pitolisant is believed to increase the release of histamine, which regulates the sleep-wake cycle and favors wakefulness.