Immune and Inflammatory Biomarkers of Hypersomnolence in Post-Acute COVID-19 Syndrome: A Comparative Sleep Phenotyping Study

Long COVID, also called post-acute COVID-19 syndrome (PACS), affects more than 65 million people worldwide. One of its most disabling and least understood symptoms is hypersomnolence, meaning excessive daytime sleepiness, prolonged sleep, and difficulty waking up. Up to one in three patients report this problem. It can disrupt daily life, making it hard to work, care for loved ones, or maintain social connections. Despite its major impact, hypersomnolence after COVID is often confused with fatigue, depression, or anxiety, leading to delayed diagnosis and limited treatment options. This project will study patients with hypersomnolence after COVID and compare them to people with idiopathic hypersomnia (a rare sleep disorder with similar symptoms) and to controls. We will use advanced sleep testing, including overnight laboratory studies, daytime nap tests, wearable activity monitors, and validated questionnaires. At the same time, we will analyze blood samples to measure immune and inflammatory markers, such as cytokines and proteins that reflect brain health. By linking these biological signals with sleep patterns and with symptoms like pain, fatigue, and mood, we aim to identify different subtypes of hypersomnolence. The goal is to better understand the hypersomnolence symptos after COVID, and to identify potential biological "signatures" that could eventually guide more targeted treatments. Beyond COVID, this project will provide insight into how immune changes are associated with sleep PACS symptoms,which can improve care for other chronic conditions as well.