Background: Although obstructive sleep apnea syndrome (OSAS) has been associated with chronic kidney
disease CKD, there are little data about early screening of renal affection in OSAS patients.
Aim of the work: To evaluate renal function in OSAS patients with or without diabetes mellitus (DM) using
blood indices [mean platelet volume (MPV) and red cell distribution width (RDW)] and serum neutrophil
gelatinase associated lipocalin (NGAL) as early markers of kidney injury.
Patients and methods: This case control analytic study was designed to enroll 20 OSAS patients with DM,
20 OSAS patients without DM, and 20 non OSAS diabetic patients as control group. All patients underwent
full over-night attended diagnostic polysomnography. Those with AHI
5 were considered to have
OSAS. Laboratory parameters including complete blood count with MPV and RDW, serum glucose, urea,
creatinine, Hemoglobin A1c, urine albumin creatinine ratio UACR and serum NGAL were done to all
enrolled participants.
Results: Urine albumin creatinine ratio UACR
3 mg/mmol was found in 11 (55%) of OSAS diabetic
group, 6 (30%) of non diabetic OSAS group and in 11 (55%) of D.M group. Both diabetic and non diabetic
OSAS patients had significantly higher RDW and NGAL compared to non OSAS diabetic. The diabetic OSAS
group had also significantly higher serum urea and creatinine compared to DM group. In OSAS patients,
RDW had significant positive correlation with UACR. Meanwhile both RDW and NGAL were determined
to have significant positive correlation with desaturation index during sleep, but not correlated to AHI.
Conclusion: Renal impairment is common in OSAS patients but more frequent if associated with diabetes
mellitus. RDW% can be used as simple screening test for early detection of renal injury in OSAS patients
with or without diabetes mellitus.