Tool to capture food-seeking behaviors in PWS clinical trials works in real life, too

Prader-Willi research foundation puts hyperphagia questionnaire to broad use

Lindsey Shapiro, PhD avatar

by Lindsey Shapiro, PhD |

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While food-seeking behaviors normally lessen as people age, they increase over time with Prader-Willi syndrome (PWS), according to a study using the Hyperphagia Questionnaire for Clinical Trials (HQ-CT), a tool commonly used in clinical trials but not in comparing a large PWS patient group to the general population.

HQ-CT scores were higher for PWS patients than the public at large, consistent with hyperphagia, a hallmark PWS symptom characterized by excessive hunger and food-seeking behaviors.

For a subset of patients who maintained low HQ-CT scores into adulthood, caregivers reported holding to strict dietary routines and limiting access to food.

The study, “Analysis of Hyperphagia Questionnaire for Clinical Trials (HQ‑CT) scores in typically developing individuals and those with Prader‑Willi syndrome,” was published in Scientific Reports.

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Hyperphagia, or obsessive hunger, is common in children with PWS

With hyperphagia, PWS patients experience intense feelings of hunger, are preoccupied by food, and adopt extreme food-seeking behaviors. The condition typically emerges during childhood, around age 8, and persists into adulthood, contributing to complications like obesity and diabetes.

Hyperphagia is a common target for investigational PWS therapies in clinical trials. The HQ-CT is a widely used and standardized metric for measuring hyperphagia in such studies and evaluating the effects of treatment.

Completed by caregivers of PWS patients, the HQ-CT contains questions related to the frequency and intensity of hyperphagic behaviors in the last two weeks. Scores range from zero to 36, and higher scores reflect more extreme hyperphagia.

Despite its wide use in research, no previous study has investigated the normal range of HQ-CT scores among PWS patients relative to the general population.

Researchers, all affiliated with the Foundation for Prader-Willi Research, administered online the HQ-CT to caregivers of 459 PWS patients, ages 5 and older, who were enrolled in the PATH for PWS natural history study (NCT03718416), an observational study sponsored by the foundation.

The survey also was given to parents or caregivers of 614 typically developing people without PWS, ages 5-26, who served as a control group.

As expected, HQ-CT scores were significantly elevated in people with PWS, with a mean score of 10.13 compared to 3.43 for controls.

Food-related behaviors tended to decrease with age among controls, “likely reflecting normal maturation,” the researchers wrote. In contrast, such behaviors increased with age among people with PWS, consistent with the known course of the disease.

Across all age groups (5-11, 12-17, and 18 or older), HQ-CT scores remained significantly higher in PWS patients compared with their age-matched peers.

Strict food security measures marked adults with lower HQ-CT scores

For both PWS and typically developing people, there was a significant difference in HQ-CT scores by weight category, with more excessive hyperphagic behaviors seen in those with a higher body mass index.

“This finding may reflect the ability of the HQ-CT to capture food behaviors that drive weight gain across populations,” the scientists noted.

While hyperphagia scores were consistently elevated in PWS patients, there was wide variability. Particularly, a small patient subset had consistently low HQ-CT scores — below a score of 7 — even after the expected age of hyperphagia onset.

To further understand such variability, the scientists held semi-structured interviews with the caregivers of 17 adult patients, ages 19-61, with these low HQ-CT scores.

All caregivers indicated that they actively managed a patient’s food intake, and about three-quarters (76.5%) of them indicated that the person with PWS had little to no options with respect to food choices, even though that person “asked questions about food throughout the day, including the type, timing, and/or portion of food to be served,” the researchers wrote.

Common strategies for dealing with hyperphagic behaviors included strictly scheduled meal and snack times, and limitations on social activities where food is present. Most (64.7%) said they implemented food security measures at home, such as locks on refrigerators and pantries or security cameras.

The scientists noted these unusually low HQ-CT scores for adults with PWS “likely reflect the considerable effort on the part of caregivers to strictly control the food environment and minimize hyperphagia-related behaviors.”

Many survey respondents (64.7%) noted they continue to be interested in new hyperphagia treatments that might help with patients’ independence and caregiving burdens.

A noted study limitation was its cross-sectional nature (when data are collected at a single point in time), with long-term information about relationships between HQ-CT, weight, and PWS patients’ environment still lacking.

The scientists expect that longitudinal data being collected through the PATH for PWS study will “allow additional insights into the interplay of PWS-associated behaviors and the environment, as well as the relationship between HQ-CT scores and changes in BMI over time.”