Estimated glomerular filtration rate (eGFR) changes after obstructive sleep apnea (OSA) treatment by positive airway pressure: data from the European Sleep Apnea Database (ESADA)

Decreased renal function is associated with OSA in the ESADA cohort (Marrone et al, J Sleep Res 2016). Aim of this study was to evaluate changes in eGFR (?eGFR) after different modalities of positive pressure treatment. Data from 1,806 OSA patients who were treated by fixed (n=1,177, CPAP) or automatic (n=485, APAP) continuous positive airway pressure were analyzed and compared with data from a group of untreated patients (n=144). Median follow-up was 541 days (IQR 220-1255). Median baseline eGFR was 91.42 ml/min/1.73m2. During follow-up, eGFR decreased particularly in the patients with eGFR below the median at baseline (p<0.0001 for effect of baseline eGFR); in the CPAP subgroup, eGFR decline was attenuated or reverted (p<0.0001 for effect of treatment), but the difference in ?eGFR between subjects with high and low baseline eGFR was not modified. Follow-up duration above median was associated with eGFR decline in the untreated and APAP groups; eGFR decline was prevented in the CPAP group (p <0.0001 by two-way ANOVA for interaction between treatment and follow-up length) (Table 1). Table 1 Follow-up duration ?eGFR No treatment ?eGFR APAP ?eGFR CPAP >=median -5.82 ± 8.64 -3.11 ± 10.84 0.58 ± 11.60 <median -0.53 ± 8.18 1.33 ± 8.29 0.63 ±10.67 Multiple regression analysis identified advanced age, female gender, cardiac failure, higher baseline eGFR and longer follow-up duration as negatively, and CPAP as positively affecting eGFR (?=3.420 [1.564/5.276], p<0.0001). Thus, OSA treatment by fixed CPAP appears to positively affect eGFR, but such an effect could not be demonstrated with APAP treatment.