Rotating shift workers with vitamin D deficiency have a higher risk of obstructive sleep apnea.

Objectives: The study aimed to evaluate the association between obstructive sleep apnea (OSA) and vitamin D deficiency (VDD) in shift workers.

Methods: This cross-sectional study included male rotating shift workers in an iron ore extraction company. Participants were classified as VDD when 25(OH)D < 20 ng/mL for a healthy population and 25(OH)D < 30 ng/mL for groups at risk for VDD. Risk of developing OSA was classified by Berlin questionnaire (BQ) and NoSAS score. Data were compared using chi-square analysis with Cramer's V as effect size, and Bonferroni correction. Multivariate logistic regression analysis was performed to investigate whether or not VDD was associated with OSA risk assessment.

Results: Among 1423 male workers, mostly younger, aged 30 to 39 years (53%), worked shifts for more than 5 years (76%). The prevalence of high risk of OSA by BQ was 16%, and 33% by NoSAS score. Additionally, 29% had VDD. In multivariate analysis, controlled for confounding factors, workers with VDD had a 52% increased chance of OSA by BQ (OR 1.52; CI95% 1.06-2.18) and a 64% increased chance of OSA by NoSAS score (OR 1.64; CI95% 1.09-2.48). After subgroup analyses, similar results were not observed in workers aged 20-29 and 30-39 years.

Conclusion: Rotating shift workers with vitamin D deficiency are more likely to have obstructive sleep apnea, assessed by the Berlin questionnaire and NoSAS score.