Effect of continuous positive airway pressure on serum cystatin C among obstructive sleep apnea syndrome patients

The purpose of the present study was to evaluate the influence of continuous positive airway pressure (CPAP) on serum cystatin C, a novel biomarker of early renal impairment, among obstructive sleep apnea (OSA) patients. Newly diagnosed severe OSA patients who treated with CPAP for 3 months were enrolled from two sleep laboratories. Serum biomarkers of renal impairment, cystatin C, creatinine and estimated glomerular filtration rate (eGFR), were detected before and after CPAP treatment. A total of 39 severe OSA patients were enrolled, 29 (74.4 %) were male, and mean age was 51.2 +/- A 12.2 years. After CPAP treatment, there were no changes of creatinine and eGFR (77.80 +/- A 20.00 vs. 75.3 +/- A 16.60 and 98.69 +/- A 31.74 vs. 100.20 +/- A 28.30, all p > 0.05), but cystatin C declined significantly (0.87 +/- A 0.18 vs. 0.77 +/- A 0.21, p = 0.000). CPAP can decrease cystatin C levels among severe OSA patients and may prevent the latent renal impairment.