Motor performance in Prader-Willi syndrome patients and its potential influence on caregiver’s quality of life

Background Prader-Willi syndrome (PWS) is a complex, multisystem genetic disorder characterized by a variety of physical, cognitive, and behavioral impairments. PWS is a unique sarcopenia model characterized by an abnormal increase in body fat mass and a decrease in muscle mass that predisposes patients to reduced physical activity, functional limitations, and disability. These manifestations may require both symptomatic and supportive management, thus negatively influencing their lifelong family caregiver's quality of life. The aim of this study was to examine the functional motor performance of adults with PWS in Taiwan and to measure the quality of life of their primary family caregivers. Methods The functional motor tests consisted of the following: (1) 30-s sit-to-stand test, (2) timed up-and-go test, (3) hand grip and lateral pinch strength tests, and (4) Berg Balance Scale. The World Health Organization Quality of Life-short form (WHOQOL-BREF) and the Short-Form 36 Health Survey Questionnaire (SF-36) were used to evaluate health-related quality of life, and the parenting stress index was used to assess the magnitude of stress within the parent-child system. Results The participants included seven adults (two females and five males) with genetically confirmed PWS and their respective main caregivers. The mean age of the adults with PWS was 25.28 years; range 18-31 years, SD 5.10; the mean BMI was 29.2 kg/m2, SD 6.43. All adults with PWS showed lower hand grip and lateral pinch strengths, fewer sit-to-stand cycles during the 30-s chair stand test, and greater average time during the timed up-and-go test when compared to the normative data on healthy adults. Balance was negatively correlated with the caregiver's health concepts of social functioning (rs -0.879, P = 0.009) and with role limitations due to physical problems (rs -0.899, P = 0.006) and emotional problems (rs -0.794, P = 0.033); hand grip strength was negatively correlated with bodily pain (rs -0.800, P = 0.031), as assessed using the SF-36 questionnaire. The timed up-and-go test was positively correlated with the social relationship domain (rs 0.831, P = 0.021), as assessed using the WHOQOL-BREF questionnaire. The parenting stress index showed no association with the PWS patient's physical activities. Conclusions All adults with PWS showed decreased upper and lower limb strength and functional mobility when compared to healthy adults. Some of their motor performance might have negative effects on their primary family members in terms of social participation and physical and emotional role limitations. Future research should explore the relationship between physical performances, psychological difficulties of PWS and caregiver's QOL.