ESPE Abstracts

Introduction: In rare cases of obesity, genetic defects lead to hyperphagia and severe early-onset obesity. Genetic testing in patients with a suspected genetic obesity phenotype is important, as it can lead to patient-tailored treatment advice. For children, the Endocrine Society (ES) recommends genetic testing in children with early-onset of obesity (<5 years) and hyperphagia. It is unclear whether these recommendations can also be used in adult obesity care. Therefore, we aimed to phenotype adult patients with genetic obesity disorders. In addition, we assessed the suitability of the pediatric ES recommendations in these patients.

Methods: We analyzed clinical data of patients with non-syndromic genetic obesity (NSO) and syndromic genetic obesity (SO), who visited our academic obesity center (Erasmus Medical Center, Rotterdam, the Netherlands). A standardized medical questionnaire, including topics concerning e.g. age of onset of obesity, hunger and satiation, was assessed. Anthropometrics, body composition (bio-impedance analysis), and resting energy expenditure (REE, indirect calorimetry) were measured. Differences between the NSO and SO groups were studied.

Results: Seventy-one patients, of which n=29 with NSO and n=42 with SO, were included: median BMI and age at intake were 40.9 vs 39.6 kg/m2 and 25.5 vs 24.8 yrs, respectively (ns). The median age of onset of obesity was 3.0 [1-5] yrs in NSO and 9.5 [4-143 yrs in SO (P<0.001). Impaired appetite regulation was present in both groups: increased feelings of hunger in 65.5 vs 61.0% and impaired satiation in 54.2 vs 51.4% in NSO vs SO (ns). Binge eating was reported in 63.4% of SO, compared to 41.4% in NSO (P=0.071). The pediatric ES recommendations were fulfilled in 58.6% of NSO and 28.6% of SO (P=0.011). Compared to NSO, SO had a higher prevalence of intellectual deficit (3.4 vs 57.1%, P<0.001), autism (6.9 vs 26.8%, P=0.035) and retinal problems (0 vs 19.0%, P=0.013). There were no differences in body composition or REE.

Conclusion: We report evident differences in phenotypic features such as the age of onset of obesity, appetite regulation, and the presence of intellectual deficit, autism and retinal problems in adults with non-syndromic genetic obesity and syndromic genetic obesity. Additionally, this study demonstrates that the Endocrine Society’s recommendations for genetic testing in children with obesity, are too strict for adults with obesity. Recommendations for genetic testing in adults with obesity are needed.