Background/Objectives: Vitamin D and mean platelet volume (MPV) have been suggested as biomarkers of obstructive sleep apnea (OSA) in adults, while pediatric data remain limited. We aimed (i) to investigate associations between vitamin D and MPV with the presence and severity of pediatric OSA and (ii) to explore potential associations between vitamin D status and sleep parameters in normal-weight affected children. Methods: A total of 138 children with polysomnography-confirmed OSA and 138 age- and sex-matched controls were enrolled. All participants underwent detailed clinical, biochemical, and overnight sleep assessments. The OSA group was stratified according to disease severity. Results: Vitamin D levels were significantly lower in OSA patients (p < 0.0001), while MPV, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were significantly higher (all p < 0.0001) than in the controls. Severe OSA was associated with elevated inflammation markers, higher insulin resistance, and lower vitamin D levels (all p < 0.0001). Vitamin D levels were inversely associated with the Apnea–Hypopnea Index (AHI) (R 0.37, adjusted r2 0.13, p < 0.0001) and Oxygen Desaturation Index (ODI) (R 0.36, adjusted r2 0.13, p < 0.0001), even after adjustments (both p < 0.0001). N1 and REM sleep were negatively associated with vitamin D in the OSA group (p = 0.01 and p = 0.02, respectively). Vitamin D deficiency was independently associated with higher odds of OSA (adjusted OR = 6.76, 95% CI: 3.97–11.51, p < 0.0001). Similarly, OSA presence was associated with lower vitamin D levels (aOR = 1.40, 95% CI: 1.06–1.94, p = 0.03). Conclusions: Vitamin D and MPV are associated with the presence and severity of pediatric OSA. Vitamin D levels were related to specific sleep architecture parameters, and MPV appeared to reflect inflammation associated with OSA, supporting their potential utility as biomarkers in pediatric OSA.
Li et al. (Sun,) studied this question.