Fig. 1From: Association of obstructive sleep apnea and diurnal variation of cystatin CDifferences in Cystatin C level Differences of cystatin C levels from the morning level to the evening level in each subject. The blue circles depict subjects with severe OSA (AHI >30) and the orange circles depict subjects without severe OSA (AHI ≤ 30). X marks denote the mean value for each group. OSA, obstructive sleep apnea; AHI, apnea-hypopnea indexBack to article page