Resistant Hypertension in Chronic Kidney Disease

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Effect of MADs on Blood Pressure

A few studies have demonstrated a favorable effect of MADS on blood pressure
reduction in patients with OSA.  A prospective randomized, controlled crossover
study found that 4 weeks of MAD therapy resulted in a 24-h ambulatory blood pres-
sure reduction of ±1.1 mmHg for systolic blood pressure and 3.4 ± 0.9 mmHg for
diastolic blood pressure compared with the control group. The magnitude of blood
pressure reduction with MADs has been overall similar to that seen with CPAP
therapy, despite MAD therapy’s less potent effect on AHI reduction [ 85 ]. It is note-
worthy that many studies have quoted longer durations of MAD usage than are typi-
cally seen in studies of CPAP.
Another randomized, crossover trial evaluated patients with mild-to-moderate
OSA assigned to 3 months of MAD versus CPAP therapy versus no therapy [ 86 ]
and found that CPAP therapy was more effective in improving sleep-disordered
breathing than MAD and placebo. However, MAD treatment was effective in
decreasing nocturnal diastolic blood pressure and in restoring the physiologic noc-
turnal dipping in blood pressure among OSA patients in contrast to CPAP therapy.

Pre-test probability

of OSA#

High

ABPM and PSG

according to guidelines

PSG

according to guidelines ABPM

Nondipper Dipper

PSG

according to guidelines Clinical follow-up

If OSA +

ABPM (if not performed previously)

Adequate treatment

Follow-up PSG + ABPM

Low

Elevated or high normal

conventional BP (SBP 130

or DBP 85 mmHg)

>_

>_

Normal conventional BP

(SBP <130 and DBP

<85 mmHg)

Elevated or high normal

conventional BP (SBP >_130

or DBP >_85 mmHg)

Normal conventional BP

(SBP <130 and DBP

<85 mmHg)

Fig. 13.5 Proposed algorithm for the diagnostic management of patients with hypertension asso-
ciated with obstructive sleep apnea (OSA). BP blood pressure, SBP systolic BP, DBP diastolic BP,
ABPM ambulatory BP monitoring, PSG polysomnography. # denotes according to clinical evalua-
tion and questionnaires, for example, Epworth and Berlin; z indicates hypertension guidelines
recommend the use of home BP monitoring in most hypertensive patients (Reproduced with per-
mission of the European Respiratory Society © [ 69 ])

13 Obstructive Sleep Apnea and Resistant Hypertension