Renal functions in obstructive sleep apnea patients

The aim of this study is to investigate possible factors influencing glomerular filtration rate (GFR) in obstructive sleep apnea (OSA).

Data of OSA patients admitted to Gaziantep University sleep clinic from January 2005 to January 2010 were retrospectively evaluated. GFR is calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Patients younger than 18 years old were excluded.

The mean age of OSA (n = 634) and control group (n = 62) were 51.13 ± 11.61 and 50.69 ± 13.88 years, respectively (p = 0.81). The mean estimated GFR (eGFR) was 90.73 ± 19.59 ml/min/1.73 m(2) in OSA patients and 94.14 ± 18.81 ml/min/1.73 m(2) in control subjects (p = 0.19). GFR was 84.25 ± 20.87 ml/min/1.73 m(2) in patients with left ventricular hypertrophy (LVH) while it was 93.94 ± 18.44 ml/min/1.73 m(2) in patients without LVH (p = 0.00). GFR of male subjects was 92.1 ± 19.23 in OSA and 95.84 ± 20.08 ml/min/1.73 m(2) in controls (p = 0.33). GFR of female and male patients in the OSA were 87.45 ± 20.10 and 92.91 ± 18.02 ml/min/1.73 m(2), respectively (p = 0.13). Serum creatinine was higher in OSA patients compared to controls (p = 0.01). GFR was 92.30 ± 19.27 in male and 88.33 ± 19.84 ml/min/1.73 m(2) in female subjects (p = 0.01). GFR was 84.86 ± 19.95 in hypertensive patients while it was 95.11 ± 18.20 ml/min/1.73 m(2) in normotensive subjects (p = 0.00). GFR was 89.30 ± 19.96 in patients with metabolic syndrome (MetS) and it was 93.46 ± 18.68 ml/min/1.73 m(2) in patients without MetS (p = 0.00).

GFR values were lower in sleep apneic patients with MetS as well as in patients with hypertension and LVH.