The relationship between obstructive sleep apnea syndrome severity and vitamin D levels in sera

Abstract

Aims: Obstructive Sleep Apnea Syndrome (OSAS) is a disorder characterized by complete or partial upper airway obstruction episodes and frequently decreased arterial oxygen saturation. Etiological factors and risk factors of OSAS are still investigated and studies in this topic continue. Until recently, researches were focused on the major effects of vitamin D on the bone metabolism and calcium homeostasis. Today; it has been found that vitamin D plays roles in many cells and tissues of human body additional to its functions in the musculoskeletal system. In our study, we aimed to examine vitamin D levels in patients who are diagnosed as OSAS and to investigate the relationship between OSAS and vitamin D deficiency. Methods: 83 volunteers, who were suspected to have OSAS, were included in the study. They all underwent polysomnography (PSG) in the Sleep Disorders Center in Pulmonary Department, between January 2015 – May 2015. Twenty cases with apnea hypopnea index (AHİ) < 5/hour were evaluated as simple snoring/control group. Cases with AHİ > 5/hour were diagnosed as OSAS; 22 patients were diagnosed as mild, 20 patients were diagnosed as moderate and 21 patients were diagnosed as severe OSAS. Blood samples of these patients were studied for the measurement of vitamin D [25(OH)D3], parathormone (PTH) , calcium (Ca), phosphor (P) levels and the samples were quickly delivered to biochemistry laboratory Results: A statistically significant difference in vitamin D levels were observed (p<0.05) between the control and OSAS groups. However, no statistically significant difference was found in PTH, Ca, P levels among these groups (p>0.05). Vitamin D levels in the control group were significantly higher than the mild and the severe OSAS patients. No statistically significant difference was observed in PTH, Ca, P levels between these patients. Conclusion: Our study indicates that there is a significant relationship between vitamin D deficiency and OSAS. This finding suggests that vitamin D deficiency may play a role in the OSAS physiopathology. There are few studies exists about the association between vitamin D deficiency and OSAS. In this regard, we think our study will contribute to the literature. Moreover; prospective, randomized, controlled studies with large series were needed.