Vitamin D Level And Mean Platelet Volume In Patients With Obstructive Sleep Apnea Syndrome

ObjectivesTo assess the serum level of vitamin D and mean platelet volume (MPV) in patients with obstructive sleep apnea syndrome (OSAS) and whether their levels correlate with OSAS severity or not.BackgroundOSAS is a clinical disorder characterized by recurrent episodes of upper airway collapse during sleep. Studies show a link between low levels of vitamin D '25(OH) D' and obstructive sleep apnea. Some studies showed that patients who have OSAS also have raised platelet aggregation and activation. MPV is considered an indicator of activation of platelet and its size. Limited studies have informed a relationship between MPV and sleep apnea.Patients and methodsA total of 65 patients with OSAS and 24 age-matched controls with completed Epworth sleepiness scale were included. OSAS diagnosis was based on polysomnography. Vitamin D was measured by ELISA, and MPV was measured by Sysmex xn-10 machine.ResultsA prospective case-control study was done on 65 OSAS cases and 24 age-matched and sex-matched controls. Vitamin D level was significantly lower among OSAS cases than controls, with lowest 25(OH) D in severe OSAS cases, whereas MPV showed nonsignificant difference between them, and the higher MPV was among severe cases. There was a significant negative correlation between vitamin D level and neck circumference (NC), apnea-hypopnea index (AHI), and desaturation index. There was a significant positive correlation between MPV level and each of NC and AHI. NC was an independent predictor for both vitamin D and MPV levels. NC, AHI, and vitamin D level are the independent risk factors for obstructive sleep apnea, with odds ratios of 2.09 and 1.6, respectively.ConclusionPatients with OSAS have decreased vitamin D level. Patients with severe OSAS have lower vitamin D level and higher MPV than other groups. Obesity may be the cause that explains this relation regarding high NC.