Endocrine Abstracts

Background: Prader-Willi syndrome (PWS) is a rare genetic, neurodevelopmental disorder. In adults the syndrome is characterized by muscular hypotonia, hyperphagia, increased risk of morbid obesity and behavioral problems. Endocrine insufficiencies are common, although insufficient function of the hypothalamus-pituitary-adrenal (HPA) axis seems to be rare. The effect of long term exposure to cortisol, which is associated with stress and obesity, is unknown in PWS. Measurement of hair cortisol is a convenient, non-invasive method to assess chronic stress.

Aims: To evaluate long-term exposure to cortisol by measurement of hair cortisol and relate levels to BMI and stress

Methods and materials: 29 adults PWS patients, 15 men and 14 women, median age 29 years, BMI 27 kg/m², participated. A scalp hair sample was collected and analyzed for cortisol concentration. In addition, the patients or their relatives answered questions related to anthropometry and factors potentially influencing hair analysis.

Results: Median hair cortisol was 3.0 pg/mg (range <1.3 to 105.6) and mean 95%CI was 12.9 pg/mg (3.7, 22.1). Hair cortisol levels were positively correlated to age and BMI (P<0.001 for both). Six patients had elevated cortisol levels, in 5 of them related to significant stressful events.

Conclusion: Hair cortisol concentrations were comparable to upper limit for healthy individuals and long-term stress lead to an increase in hair cortisol. All together our results indicate a normal function of the HPA-axis in this cohort of adults with PWS.