Relationship between body mass index and nutritional status across genetic subtypes of Prader-Willi syndrome

The relationship between Prader-Willi Syndrome (PWS) genetic subtypes and nutritional status is generally unknown. We aimed to evaluate the relationship between body mass index (BMI) and nutritional status across genetic subtypes of PWS.

This retrospective cross-sectional study included male and female individuals over 8 years old with a confirmed genetic diagnosis of PWS and subtype determination. This study was conducted at a health facility led by a non-governmental organization that provides regular outpatient transdisciplinary care for rare diseases. We excluded individuals with a history of growth hormone treatment and pharmacological treatments for nutritional purposes. Participants were grouped based on the presence or absence of a genetic deletion subtype. The BMI (kg/m²) was calculated upon admission. Nutritional assessment was conducted in accordance with World Health Organization standards.

A total of 41 individuals with PWS were included, with a mean age of 19.4 ± 6.7 years and a mean BMI of 40.2 ± 12.7 kg/m². The most frequent genotype was deletion (n = 28, 68 %). Compared to non-deletion participants, the deletion group showed a significantly higher mean BMI (42.4 ± 14.2 kg/m² vs. 35.5 ± 7.2 kg/m², p = 0.045). The nutritional status of obesity was significantly more prevalent in individuals with the deletion subtype (93 %, 26/28) compared to those with a non-deletion subtype (62 %, 9/13; p = 0.006). However, when stratified by age groups, the association between deletion and nutritional status was observed only among adults, in whom deletion was linked to a higher prevalence of obesity (94 % vs. 50 %, p = 0.006) and a higher mean BMI (47.8 ± 14.9 kg/m² vs. 35.1 ± 8.6 kg/m², p = 0.04).

In this study involving individuals with PWS, adults with the genetic deletion subtype presented higher BMI and more severe obesity compared to patients with non-deletion genotypes.