Abstract
Obstructive sleep apnea (OSA) is characterized by chronic intermittent hypoxemia, which is associated with progressive loss of kidney function, where postprandial fluctuations in renal physiology may further compromise oxygen supply and kidney function. Therefore, we measured biomarkers of acute kidney injury (AKI) following a high-fat meal with and without intermittent hypoxemia. Eighteen healthy young men (mean age [SD]: 22.7 years [3.1]) and seven middle-aged to older individuals with OSA (54.4 years [6.4]) consumed a high-fat meal during normoxia or intermittent hypoxemia (~15 hypoxic cycles per hour, ~85% oxyhemoglobin saturation) for 6 h. We observed no changes in estimated glomerular filtration rate and plasma concentrations of creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) at any measured time points. In both groups, plasma concentrations of interleukin-18 (IL-18) increased after 6 h during normoxia only (p = 0.033, ηp 2 = 0.122), and plasma concentrations of liver-type fatty acid-binding protein (L-FABP) transiently decreased after 3 h in both conditions (p = 0.008, ηp 2 = 0.152). These findings indicate that AKI biomarkers are not acutely elevated during the postprandial state with or without intermittent hypoxemia, suggesting that other mechanisms may play more important roles in the progression of kidney disease in OSA.