Vitamin D Status in Obstructive Sleep Apnea With and Without Comorbidities

Serum 25-Hydroxyvitamin D Across Obstructive Sleep Apnea Phenotypes With and Without Comorbidities: A Retrospective Comparative Study

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT07788391

Enrollment

269

Registered

2026-08-26

Start date

2024-01-01

Completion date

2026-04-20

Last updated

2026-08-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obstructive Sleep Apnea, Vitamin D Deficiency

Keywords

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

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.

Detailed description

This retrospective comparative study evaluates serum 25-hydroxyvitamin D \[25(OH)D\] status across clinically distinct obstructive sleep apnea (OSA) phenotypes. Participants were classified into four groups: healthy controls, symptomatic participants with simple snoring/non-OSA (apnea-hypopnea index \[AHI\] \<5 events/hour), patients with OSA without comorbidities, and patients with OSA with comorbidities. OSA was defined as AHI ≥5 events/hour and categorized as mild, moderate, or severe according to conventional AHI thresholds. Among patients with OSA, comorbid OSA was defined by the presence of at least one documented chronic condition, including hypertension, diabetes mellitus, cardiovascular disease, dyslipidemia, or hypothyroidism. Demographic and anthropometric characteristics, serum 25(OH)D concentrations, available routine laboratory measurements, and polysomnographic parameters were retrospectively obtained from existing medical records and hospital databases. The study compares vitamin D status across the four groups and evaluates whether serum 25(OH)D concentrations and vitamin D categories are associated with OSA severity. The study also explores whether differences in vitamin D status across OSA phenotypes persist after accounting for age, sex, and body mass index.

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

RETROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

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.

Exclusion criteria

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.

Design outcomes

Primary

Measure	Time frame	Description
Serum 25-Hydroxyvitamin D Levels Across Study Groups	During the retrospective study period (2024-2026)	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.

Secondary

Measure	Time frame	Description
Distribution of Vitamin D Status Across Study Groups	During the retrospective study period (2024-2026)	Participants were categorized according to serum 25-hydroxyvitamin D \[25(OH)D\] concentrations as \<20 ng/mL, 20-30 ng/mL, or \>30 ng/mL. The distribution of these vitamin D categories was compared among healthy controls, simple snoring/non-OSA participants, patients with OSA without comorbidities, and patients with OSA with comorbidities.

Countries

Turkey (Türkiye)

Contacts

PRINCIPAL_INVESTIGATORBekir Sami Uyanık, MD, Prof. Dr.

Hisar Intercontinental Hospital

PRINCIPAL_INVESTIGATOROrhan Dalkılıç, MD, Assistant Professor