{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T11:23:58Z","timestamp":1783596238272,"version":"3.55.0"},"reference-count":40,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T00:00:00Z","timestamp":1783555200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background and Objectives: Parkinson\u2019s disease (PD) includes a prodromal phase characterized by non-motor symptoms (NMS). We investigated whether sleep disturbances co-aggregate with other NMS in suspected prodromal PD (p-PD) to refine early phenotyping and risk stratification. Materials and Methods: A population-based survey was conducted in Kaunas, Lithuania. Participants from the Kaunas City preventive health screening cohort (2024\u20132025) were screened using the Innsbruck REM Sleep Behaviour Disorder Inventory (RBD-I). Sixty-two individuals were included: 31 with suspected p-PD and 31 controls. Demographic characteristics, clinical features, sleep symptoms, olfactory function, autonomic symptoms, cognition, and mood were assessed. Between-group comparisons and within-group correlation analyses were performed. Results: Groups did not differ in age, sex, education, lifestyle exposures, or family history (all p &gt; 0.05). Compared with controls, individuals with suspected p-PD had a higher prevalence of insomnia (71.0% vs. 12.9%, p &lt; 0.001), pathological daytime sleepiness (22.6% vs. 0%, p = 0.005), cognitive impairment (54.8% vs. 16.1%, p = 0.001), and constipation (32.3% vs. 0%, p = 0.002). As expected from the predefined enrichment strategy, hyposmia and orthostatic hypotension (OH) were observed only among suspected p-PD participants. Within the suspected p-PD group, the Non-Motor Symptoms Questionnaire (NMSQ) scores correlated with depressive\/anxiety symptoms (r = 0.578, p = 0.001). Olfactory dysfunction correlated with cognitive impairment (r = 0.410, p = 0.001) and depressive\/anxiety symptoms (r = 0.396, p = 0.001). Conclusions: Sleep disturbances, particularly insomnia and excessive daytime sleepiness, co-occurred with cognitive, affective, and gastrointestinal non-motor manifestations in individuals with suspected p-PD, supporting the concept of a broader prodromal phenotype. Comprehensive screening in individuals with RBD symptoms may improve early PD risk stratification beyond single-marker approaches.<\/jats:p>","DOI":"10.3390\/jcm15145371","type":"journal-article","created":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T10:16:22Z","timestamp":1783592182000},"page":"5371","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Associations Between Sleep and Non-Motor Symptoms in RBD-Screened Suspected Prodromal Parkinson\u2019s Disease with Hyposmia or Orthostatic Hypotension"],"prefix":"10.3390","volume":"15","author":[{"given":"Erlandas","family":"Paul\u0117kas","sequence":"first","affiliation":[{"name":"Department of Neurology, Lithuanian University of Health Sciences, LT-44307 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rugil\u0117","family":"Mu\u010dait\u0117","sequence":"additional","affiliation":[{"name":"Department of Neurology, Lithuanian University of Health Sciences, LT-44307 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Evelina","family":"Paj\u0117dien\u0117","sequence":"additional","affiliation":[{"name":"Department of Neurology, Lithuanian University of Health Sciences, LT-44307 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0868-457X","authenticated-orcid":false,"given":"Abdonas","family":"Tamo\u0161i\u016bnas","sequence":"additional","affiliation":[{"name":"Institute of Cardiology, Lithuanian University of Health Sciences, LT-44307 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2736-3111","authenticated-orcid":false,"given":"Vaiva","family":"Lesauskait\u0117","sequence":"additional","affiliation":[{"name":"Institute of Cardiology, Lithuanian University of Health Sciences, LT-44307 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K\u0119stutis","family":"Petrikonis","sequence":"additional","affiliation":[{"name":"Department of Neurology, Lithuanian University of Health Sciences, LT-44307 Kaunas, Lithuania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"17013","DOI":"10.1038\/nrdp.2017.13","article-title":"Parkinson disease","volume":"3","author":"Poewe","year":"2017","journal-title":"Nat. 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