Retrospective longitudinal study on the long-term impact of COVID-19 infection on polysomnographic evaluation in patients with Prader-Willi syndrome.

Background: To evaluate the impact of coronavirus disease 2019 (COVID-19) on polysomnographic evaluation in patients with Prader-Willi syndrome (PWS).

Patients And Methods: A retrospective cohort study of two consecutive overnight polysomnograms (PSG) in 92 PWS patients (mean age 9.1, range 3.1-22 years). 57/92 participants (35 female) had a COVID-19 infection between the two consecutive examinations. 35 patients (21 female) had no infection (control group). Distribution of genetics was as follows: 13/57 (22.8%) deletion, 19/57 (33.3%) uniparental disomy, 2/57 (3,5%) imprinting defect, 3/57 (5.3%) non-deletion, 20/57 (35.1%) diagnosed by analyses of the methylation pattern of chromosome 15q11-13. Mean time interval between COVID-19 infection and post-COVID-19 evaluation was 96.2 days.

Results: Course of COVID-19 infection was asymptomatic 8/82 (9.8%), mild 63/82 (76.8%), medium 11/84 (13.4%). The five most frequently experienced symptoms in PWS patients were fever (56.1%); headache (45.1%); cold (42.7%); cough (31.7%) and body aches (21.95%). PWS patients who had COVID-19 infection had significantly lower mean oxygen saturation (SpO2) measured by pulse oximetry (post 94.8% vs. pre 95.7%, p = 0.001), lower detected lowermost SpO2 (post 86.2 vs. pre 87.3%, p = 0.003), and higher occurrence of hypopnoea (post 13.9 vs. pre 10.7, p = 0.001). Time in optimal SpO2 (95-100%) decreased significantly (post 54.3% vs. pre 73.8%, p = 0.001), whereas an increase was observed in time in suboptimal SpO2 (90-95%) (post 45.5% vs. 25.8%, p = 0.001) and in time in poor SpO2 (< 90%) (post 0.7% vs. pre 0.2%, p = 0.030). Body-Mass-Index (BMI)-SDS for PWS showed no differences between the groups at any time. BMI-SDS-differences showed no influence on differences in SpO2 evaluations. In the genetic subgroup with deletion there was a statistically significant effect on an increased number of OSA (p = 0.027). The genetic subgroup with uniparental disomy (UPD) was associated with a reduced risk of higher HF (p = 0.035) and less hypopnea (p = 0.011).

Conclusion: PWS patients predominantly experienced only mild to medium symptoms during COVID-19 infection without necessity of hospitalisation. However, on average three months after infection, differences in PSG evaluations were still apparent, manifesting in lower SpO2 and more frequent hypopnea. A long-lasting impairment of the pulmonary system due to the COVID-19 infection might be responsible.