328
Possible Mechanisms of Action of CPAP Treatment on Blood
Pressure Control
Mechanism of action of CPAP on the treatment of HT is not clearly known; however
CPAP was shown to reduce RAAS [ 52 ] and SNS activity [ 53 , 54 ]; decrease plasma
noradrenaline levels [ 55 ], free-oxygen radicals, and inflammatory mediators [ 56 ,
57 ]; and improve the endothelial dysfunction [ 30 ] and arterial stiffness [ 36 , 37 ]
associated with OSAS.
Possible Role of CPAP in HT Treatment of CKD Patients
Although OSAS was found to be related to RH in patients with both CKD and
kidney failure [ 23 ], no study has been designed to address the possible favorable
effects of CPAP treatment on BP control in patients with both OSAS and
CKD. Mainly three mechanisms have been proposed in the strong relationship
between OSAS, RH, and CKD: hypervolemia, high RAAS, and SNS activity. Since
treatment of OSAS with CPAP has been shown to reduce RAAS and SNS activity
[ 52 – 54 ], CPAP is strongly expected to be effective in BP control also in CKD
patients.
Arterial stiffness is common and exaggerated in CKD patients, and it plays an
important role in HT of CKD. CPAP was shown to effectively improve arterial stiff-
ness in non-CKD patients [ 39 ]; thus it may also be effective in this population in the
treatment of arterial stiffness and HT.
In addition to favorable effects on BP control, CPAP may also increase renal
survival by reducing glomerular hyperfiltration, intraglomerular HT, glomeruloscle-
rosis, and renal fibrosis.
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