Sleep architecture and vitamin D in hypertensives with obstructive sleep apnea: A polysomnographic study

Background. Obstructive sleep apnea (OSA) and arterial hypertension (AH) are closely linked disorders with common pathophysiological features.Objectives. The present study aimed to investigate the relationship between AH and OSA by examining sleep architecture, vitamin D concentration and electrolyte levels in patients with these coexisting conditions.Material and methods. A total of 133 patients suspected of having OSA were recruited for examination. The participants were divided into 2 groups: hypertensives (n=52); and normotensives (n=81). One full-night polysomnographic examinations were conducted, followed by the statistical analysis of the collected data.Results. Hypertensive individuals displayed increased apnea-hypopnea index (AHI), oxygen desaturation index (ODI), respiratory arousal index (RAI), and periodic limb movement index (PLMI) as compared to non-hypertensive individuals. Moreover, sleep efficiency (SE), the bruxism arousal index (BAI) and oxygen saturation (SpO2) level were decreased in the hypertensive group. In terms of biochemical parameters, hypertensive individuals exhibited a lower magnesium (Mg) level, and higher levels of C-reactive protein (CRP), uric acid (UA) and glucose. Notably, there were no statistical differences in vitamin D concentration between hypertensive and normotensive individuals.Conclusions. The study explored the potential influence of calcium (Ca), Mg, vitamin D, and UA concentrations on the sleep architecture of patients with comorbid AH and OSA. The findings revealed several notable associations. Firstly, sleep fragmentation correlated with Ca level, suggesting a potential role for both Ca and vitamin D in sleep arousals. Secondly, a higher UA concentration was linked to a higher AHI and increased sleep fragmentation. Additionally, alterations in Mg concentration were observed among hypertensive individuals with OSA. However, further research is needed to fully comprehend the potential impact of these factors on the sleep architecture of hypertensive individuals with apnea.