Fig. 3From: Copeptin, pro-atrial natriuretic peptide and pro-adrenomedullin as markers of hypoxic stress in patients with obstructive sleep apnea—a prospective intervention studyCircadian variation of biomarker levels in patients with OSA between morning (6–9 a.m.) and evening (8–10 p.m.) hours. Error bars represent 95% Confidence Intervals. P-values were calculated using the Wilcoxon signed-rank testBack to article page