Effect of Obstructive Sleep Apnea Treatment on Renal Function in Patients with Cardiovascular Disease.
RATIONALE
Obstructive sleep apnea (OSA) is associated with impaired renal function, but uncertainty exists over whether OSA treatment can influence renal outcomes.


OBJECTIVES
To determine the effects of continuous positive airway pressure (CPAP) on renal function in subjects with coexisting OSA and cardiovascular disease.


METHODS
This was a substudy of the international SAVE (Sleep Apnea Cardiovascular Endpoints) trial, in which 2,717 patients with moderate to severe OSA and established coronary or cerebrovascular disease were randomized to receive either CPAP plus usual care or usual care alone. Renal function and adverse renal events were compared between the CPAP (n = 102) and usual care (n = 98) groups. Glomerular filtration rate was estimated at randomization and at the end of follow-up, and the urinary albumin-to-creatinine ratio was measured at study exit.


MEASUREMENTS AND MAIN RESULTS
In 200 substudy participants (mean age, 64 yr; median, 4% oxygen desaturation index; 20 events/h; mean estimated glomerular filtration rate at baseline, 82 ml/min/1.73 m2), the median (interquartile range) changes in estimated glomerular filtration rate (ml/min/1.73 m2/yr) were -1.64 (-3.45 to -0.740) in the CPAP group and -2.30 (-4.53 to -0.71) in the usual care group (P = 0.21) after a median of 4.4 years. There were no between-group differences in end-of-study urinary albumin-to-creatinine ratio or in the occurrence of serious renal or urinary adverse events during the trial. The level of CPAP adherence did not influence the findings.


CONCLUSIONS
CPAP treatment of OSA in patients with cardiovascular disease does not alter renal function or the occurrence of renal adverse events. Clinical trial registered with www.clinicaltrials.gov (NCT00738179).
['Loffler|Kelly A|KA|', 'Heeley|Emma|E|', 'Freed|Ruth|R|', 'Anderson|Craig S|CS|', 'Brockway|Ben|B|', 'Corbett|Alastair|A|', 'Chang|Catherina L|CL|', 'Douglas|James A|JA|', 'Ferrier|Katherine|K|', 'Graham|Neil|N|', 'Hamilton|Garun S|GS|', 'Hlavac|Michael|M|', 'McArdle|Nigel|N|', 'McLachlan|John|J|', 'Mukherjee|Sutapa|S|', 'Naughton|Matthew T|MT|', 'Thien|Francis|F|', 'Young|Alan|A|', 'Grunstein|Ronald R|RR|', 'Palmer|Lyle J|LJ|', 'Woodman|Richard J|RJ|', 'Hanly|Patrick J|PJ|', 'McEvoy|R Doug|RD|', '|||']
D000368:Aged D002318:Cardiovascular Diseases D045422:Continuous Positive Airway Pressure D005260:Female D006801:Humans D007668:Kidney D007677:Kidney Function Tests D008297:Male D008875:Middle Aged D051436:Renal Insufficiency, Chronic D020181:Sleep Apnea, Obstructive
obstructive sleep apnea continuous positive airway pressure glomerular filtration rate albuminuria randomized controlled trial