Vitamin D Status in Obstructive Sleep Apnea With and Without Comorbidities

NCT07788391 | Completed

• 1 other identifier: 26-78
• Study Type: observational
• Target: 269
• Locations: 1 country
• Sites: 1

Brief Summary

This retrospective observational study evaluates the relationship between vitamin D status and obstructive sleep apnea (OSA) in adults. The study includes 269 participants divided into four groups: healthy controls, participants with simple snoring without OSA, patients with OSA without comorbidities, and patients with OSA with comorbidities. The main objective is to compare serum 25-hydroxyvitamin D \[25(OH)D\] levels among these groups and to examine whether vitamin D status is associated with the presence and severity of OSA. Demographic characteristics, body mass index, laboratory measurements, and available overnight polysomnography findings are evaluated using existing medical records. The study also examines the distribution of vitamin D deficiency across the study groups and the relationship between vitamin D categories and OSA severity.

Conditions

Vitamin D Deficiency; Obstructive Sleep Apnea

Keywords

Obstructive Sleep Apnea; 25-Hydroxyvitamin D; Polysomnography; Apnea-Hypopnea Index; Vitamin D Deficiency

Outcome Measures

Primary Outcomes (1)

• Serum 25-Hydroxyvitamin D Levels Across Study Groups

  Serum 25-hydroxyvitamin D \[25(OH)D\] concentrations were compared among healthy controls, simple snoring/non-OSA participants, patients with OSA without comorbidities, and patients with OSA with comorbidities.

  During the retrospective study period (2024-2026)

Secondary Outcomes (1)

• Distribution of Vitamin D Status Across Study Groups

  During the retrospective study period (2024-2026)

Other Outcomes (1)

• Association of Vitamin D Status With Polysomnographic Severity of OSA

  During the retrospective study period (2024-2026)

Study Arms (4)

Healthy Controls

Individuals without documented obstructive sleep apnea or the predefined comorbid conditions, included as the healthy reference group. No study-specific intervention was assigned.

Simple Snoring / Non-OSA

Symptomatic participants who underwent polysomnography and had an apnea-hypopnea index (AHI) \<5 events/h. No study-specific intervention was assigned.

OSA Without Comorbidities

Participants with OSA (AHI ≥5 events/h) without documented hypertension, diabetes mellitus, cardiovascular disease, dyslipidemia, or hypothyroidism. No study-specific intervention was assigned.

OSA With Comorbidities

Participants with OSA (AHI ≥5 events/h) and at least one documented comorbid condition, including hypertension, diabetes mellitus, cardiovascular disease, dyslipidemia, or hypothyroidism. No study-specific intervention was assigned.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consisted of adults evaluated at Hisar Intercontinental Hospital between 2024 and 2026. Participants included a healthy control group and adults who underwent overnight polysomnography because of symptoms suggestive of sleep-disordered breathing. PSG-evaluated participants were classified as simple snoring/non-OSA (AHI \<5 events/hour), OSA without comorbidities, or OSA with comorbidities. The final study population included 269 participants: 81 healthy controls, 49 non-OSA participants, 50 patients with non-comorbid OSA, and 89 patients with comorbid OSA.

You may qualify if:

• Adults aged 18 years or older. Participants with available serum 25-hydroxyvitamin D \[25(OH)D\] measurements. For PSG-evaluated groups, availability of overnight polysomnography data allowing classification according to the apnea-hypopnea index (AHI).
• Participants meeting the predefined criteria for one of the study groups: healthy control, simple snoring/non-OSA, OSA without comorbidities, or OSA with comorbidities.

You may not qualify if:

• Missing or insufficient data required for study-group classification. Missing serum 25(OH)D measurements. Incomplete polysomnographic data preventing determination of OSA status or severity in PSG-evaluated participants.

Sponsors & Collaborators

• Hisar Intercontinental Hospital: lead

Study Sites (1)

Hisar Intercontinental Hospital

Istanbul, Istanbul, 34768, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Vitamin D Deficiency; Sleep Apnea, Obstructive

Condition Hierarchy (Ancestors)

Avitaminosis; Deficiency Diseases; Malnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Sleep Apnea Syndromes; Apnea; Respiration Disorders; Respiratory Tract Diseases; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases

Study Officials

• Bekir Sami Uyanık, MD, Prof. Dr.

  Hisar Intercontinental Hospital

  PRINCIPAL INVESTIGATOR

• Orhan Dalkılıç, MD, Assistant Professor

  Hisar Intercontinental Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Clinical Biochemistry

Study Record Dates

• First Submitted: August 23, 2026
• First Posted: August 26, 2026
• Study Start: January 1, 2024
• Primary Completion: April 20, 2026
• Study Completion: April 20, 2026
• Last Updated: August 26, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)