Epidemiology and Population Health

Long-term health outcomes in patients with Prader–Willi Syndrome: a nationwide cohort study in Denmark



Prader–Willi syndrome (PWS) is a rare congenital disease that affects growth, sexual development, cognitive function and behavior. Individuals exhibit food preoccupation and hyperphagia, which may lead to obesity with premature morbidity and mortality. The aim of this work was to evaluate the risk of venous thromboembolisms (VTEs), myocardial infarction, pulmonary hypertension, sleep apnea, depression, anxiety and all-cause mortality among persons with PWS as compared with an age- and sex-matched general-population cohort.


All persons diagnosed with PWS (n=155) were identified in the Danish Health Registries; an age- and sex-matched comparison group was selected from the general population of Denmark (n=15 500); diseases of interest were identified through the health registry and cause of death register. Follow-up began on date of birth or first medical record availability through to first occurrence of an outcome of interest; follow-up ceased at emigration from Denmark or end of study. Incidence rates (IRs) were calculated and Cox's proportional hazards models were used to understand the relative risk (RR) of disease.


The IRs for VTE among patients with PWS was 144 (60–347) per 100 000 person-years. Risks for VTE events and all-cause mortality were 9.4 times (95% confidence interval (CI): 3.7–23.5) and 11.0 times (95% CI: 5.7–21.1) higher, respectively, for patients with PWS versus the general population. Increased risks were also found individually for deep venous thromboses (DVTs) (RR: 9.1; 95% CI: 3.2–25.2), pulmonary embolisms (RR: 11.0; 95% CI: 1.4–86.9), myocardial infarction (RR: 7.2; 95% CI: 1.7–30.2) and anxiety (RR: 2.8; 95% CI: 1.0–7.5). No cases of pulmonary hypertension, sleep apnea or depressive disorders were identified within this PWS cohort.


Multiple cardiovascular and behavioral illnesses are more likely to occur among patients with PWS than within the general population. These increased risks may provide an impetus for enhanced disease prevention, screening, diagnosis and treatment.

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Correspondence to E Hedgeman.

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Competing interests

At the time of this work, Drs Malobisky and Kreher were employees of Zafgen; Dr Malobisky has financial holdings in Zafgen. Dr Fryzek, Ms Carter and Dr Hedgeman have received compensation as consultants for Zafgen. Dr Braun has received compensation as a consultant for EpidStat.

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Hedgeman, E., Ulrichsen, S., Carter, S. et al. Long-term health outcomes in patients with Prader–Willi Syndrome: a nationwide cohort study in Denmark. Int J Obes 41, 1531–1538 (2017). https://doi.org/10.1038/ijo.2017.139

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