Effect of angiotensin converting enzyme inhibition [Cilazapril] on blood pressure recording in hypertensive obstructive sleep apneic patients

Effect of different treatments for obstructive sleep apnoea on blood pressure

OBJECTIVE

Obstructive sleep apnoea (OSA) is a common cause of secondary hypertension. This network meta-analysis (NMA) assessed the effect of different OSA treatments on lowering blood pressure.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for relevant randomized controlled trials. The search strategies included the concepts of OSA, blood pressure, hypertension, and blood pressure-reducing treatments without language or data restriction (from inception to 1 June 2021). The outcomes included office SBP, office DBP, daytime SBP (dSBP) and DBP (dDBP), and night-time SBP (nSBP) and DBP (nDBP). A Bayesian network meta-analysis was performed, and mean differences with 95% credibility intervals were calculated.

RESULTS

We reviewed 49 randomized controlled trials involving 4893 patients and the following interventions: continuous positive-airway pressure (CPAP), mandibular advancement devices, nocturnal supplemental oxygen, surgery, β-blocker, angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs), renal sympathetic denervation (RDN), mineralocorticoid receptor antagonists (MRAs), calcium channel blockers. MRAs were significantly associated with blood pressure reduction followed by ACEI/ARB. RDN could reduce office SBP, office DBP, 24-h SBP, 24-h DBP, dSBP, and dDBP. CPAP also demonstrated modest blood pressure lowering.

CONCLUSION

MRAs and ACEIs/ARBs can reduce blood pressure effectively in patients with OSA. RDN is a novel hypertension treatment that lowered blood pressure in such patients. CPAP was associated with mild but stable blood pressure reduction, and it might be helpful as an adjunctive therapy in OSA patients with hypertension.

REVIEW REGISTRATION

This systematic review and meta-analysis was registered in PROSPERO: CRD42021240891.

Drug therapy for obstructive sleep apnoea in adults

BACKGROUND

The treatment of choice for moderate to severe obstructive sleep apnoea (OSA) is continuous positive airways pressure (CPAP) applied via a mask during sleep. However, this is not tolerated by all individuals and its role in mild OSA is not proven. Drug therapy has been proposed as an alternative to CPAP in some patients with mild to moderate sleep apnoea and could be of value in patients intolerant of CPAP. A number of mechanisms have been proposed by which drugs could reduce the severity of OSA. These include an increase in tone in the upper airway dilator muscles, an increase in ventilatory drive, a reduction in the proportion of rapid eye movement (REM) sleep, an increase in cholinergic tone during sleep, an increase in arousal threshold, a reduction in airway resistance and a reduction in surface tension in the upper airway.

OBJECTIVES

To determine the efficacy of drug therapies in the specific treatment of sleep apnoea.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials. Searches were current as of July 2012.

SELECTION CRITERIA

Randomised, placebo controlled trials involving adult patients with confirmed OSA. We excluded trials if continuous positive airways pressure, mandibular devices or oxygen therapy were used. We excluded studies investigating treatment of associated conditions such as excessive sleepiness, hypertension, gastro-oesophageal reflux disease and obesity.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by The Cochrane Collaboration.

MAIN RESULTS

Thirty trials of 25 drugs, involving 516 participants, contributed data to the review. Drugs had several different proposed modes of action and the results were grouped accordingly in the review. Each of the studies stated that the participants had OSA but diagnostic criteria were not always explicit and it was possible that some patients with central apnoeas may have been recruited.Acetazolamide, eszopiclone, naltrexone, nasal lubricant (phosphocholinamine) and physiostigmine were administered for one to two nights only. Donepezil in patients with and without Alzheimer's disease, fluticasone in patients with allergic rhinitis, combinations of ondansetrone and fluoxetine and paroxetine were trials of one to three months duration, however most of the studies were small and had methodological limitations. The overall quality of the available evidence was low.The primary outcomes for the systematic review were the apnoea hypopnoea index (AHI) and the level of sleepiness associated with OSA, estimated by the Epworth Sleepiness Scale (ESS). AHI was reported in 25 studies and of these 10 showed statistically significant reductions in AHI.Fluticasone in patients with allergic rhinitis was well tolerated and reduced the severity of sleep apnoea compared with placebo (AHI 23.3 versus 30.3; P < 0.05) and improved subjective daytime alertness. Excessive sleepiness was reported to be altered in four studies, however the only clinically and statistically significant change in ESS of -2.9 (SD 2.9; P = 0.04) along with a small but statistically significant reduction in AHI of -9.4 (SD 17.2; P = 0.03) was seen in patients without Alzheimer's disease receiving donepezil for one month. In 23 patients with mild to moderate Alzheimer's disease donepezil led to a significant reduction in AHI (donepezil 20 (SD 15) to 9.9 (SD 11.5) versus placebo 23.2 (SD 26.4) to 22.9 (SD 28.8); P = 0.035) after three months of treatment but no reduction in sleepiness was reported. High dose combined treatment with ondansetron 24 mg and fluoxetine 10 mg showed a 40.5% decrease in AHI from the baseline at treatment day 28. Paroxetine was shown to reduce AHI compared to placebo (-6.10 events/hour; 95% CI -11.00 to -1.20) but failed to improve daytime symptoms.Promising results from the preliminary mirtazapine study failed to be reproduced in the two more recent multicentre trials and, moreover, the use of mirtazapine was associated with significant weight gain and sleepiness. Few data were presented on the long-term tolerability of any of the compounds used.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend the use of drug therapy in the treatment of OSA. Small studies have reported positive effects of certain agents on short-term outcomes. Certain agents have been shown to reduce the AHI in largely unselected populations with OSA by between 24% and 45%. For donepezil and fluticasone, studies of longer duration with a larger population and better matching of groups are required to establish whether the change in AHI and impact on daytime symptoms are reproducible. Individual patients had more complete responses to particular drugs. It is possible that better matching of drugs to patients according to the dominant mechanism of their OSA will lead to better results and this also needs further study.

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Drug therapy for obstructive sleep apnoea in adults

BACKGROUND

The treatment of choice for moderate to severe obstructive sleep apnoea (OSA) is continuous positive airways pressure (CPAP) via a mask during sleep. However this is not tolerated by all patients and its role in mild OSA is not proven. Drug therapy has been proposed as an alternative to CPAP in some patients with mild to moderate sleep apnoea and could be of value in patients intolerant of CPAP. A number of mechanisms have been proposed by which drugs could reduce the severity of OSA. These include an increase in tone in the upper airway dilator muscles, an increase in ventilatory drive, a reduction in the proportion of REM sleep, an increase in cholinergic tone during sleep, a reduction in airway resistance and a reduction in surface tension in the upper airway.

OBJECTIVES

To determine the efficacy of drug therapies in the treatment of sleep apnoea.

SEARCH STRATEGY

We carried out searches on the Cochrane Airways Group Specialised Register of trials. Searches were current as of July 2005.

SELECTION CRITERIA

Randomised, placebo controlled trials involving adult patients with confirmed OSA . We excluded trials if continuous positive airways pressure, mandibular devices or oxygen therapy were used. No restriction was placed upon publication language or trial duration.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed studies for inclusion, undertook data extraction according to pre-specified entry criteria, and quality assessment of studies. No response for further information was forthcoming from study authors. Results were expressed as mean differences and 95% Confidence Intervals (CI).

MAIN RESULTS

Twenty-six trials of 21 drugs, involving 394 participants contributed data to the review. Most of the studies were small and many trials had methodological limitations. Each of the studies states that the subjects had OSA but diagnostic criteria were not always explicit and it is possible that some patients with central apnoeas may have been recruited. Six drugs had some impact on OSA severity and two altered daytime symptoms. One study reported that apnoea hypopnea index (AHI) was lower following treatment with intranasal fluticasone compared with placebo (23.3 versus 30.3) in 24 participants with sleep apnoea and rhinitis. Subjective alertness in the daytime also improved. Physostigmine gave an AHI of 41 compared to 54 on placebo (10 participants) and in a similar study Mirtazipine 15 mg produced an AHI of 13 compared to 23.7 for placebo (10 participants). Topical nasal lubricant given twice overnight resulted in an AHI of 14 compared to 24 with placebo (10 participants). These three latter studies were of single night crossover design and so there are no data on the acceptability of these treatments or their effect on symptoms. Paroxetine was shown to reduce AHI to 23.3 compared to 30.3 for placebo, most of the 20 participants tolerated the treatment but there was no improvement in daytime symptoms. Acetazolamide also reduced the AHI (one crossover trial of nine patients, mean difference 24 (95% CI 4 to 44). However there was no symptomatic benefit from the drug and it was poorly tolerated in the long term. Protriptyline led to a symptomatic improvement (improved versus not improved) in two out of three crossover trials (13 participants, Peto Odds Ratio 29.2 (95% CI 2.8 to 301.1) but there was no change in the apnoea frequency. In one trial naltrexone did reduce AHI, but total sleep time favoured placebo. No significant beneficial effects were found for medroxy progesterone, clonidine, mibefradil, cilazapril, buspirone, aminophylline, theophylline doxapram, ondansetron or sabeluzole.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend the use of drug therapy in the treatment of OSA. Small studies have reported positive effects of certain agents on short-term outcome. Certain agents have been shown to reduce the AHI in largely unselected populations with OSA by between 24 and 45%. For fluticasone, mirtazipine, physostigmine and nasal lubricant, studies of longer duration are required to establish whether this has an impact on daytime symptoms. Individual patients had more complete responses to particular drugs. It is likely that better matching of drugs to patients according to the dominant mechanism of their OSA will lead to better results and this also needs further study.

Association between blood pressure reduction with antihypertensive treatment and sleep apnea activity

This study investigated whether a drug therapy-induced reduction in nocturnal blood pressure (BP) was associated with decreased sleep apnea activity. Two polysomnographies from 54 hospitalized male hypertensive, obstructive sleep apnea patients were analyzed in a double-blind, randomized, parallel-group trial of the angiotensin-converting enzyme inhibitor cilazapril (C), 2.5 mg once daily, or placebo (P). Blood pressure was measured by means of an intra-arterial catheter. Compared with P, C lowered mean arterial BP during non-rapid eye movement (NREM) (-8.3 +/- 10.7 mm Hg, P = .05) and REM sleep (-8.6 +/- 10.1 mm Hg, P = .02). Respiratory disturbance index (-8.6 +/- 3.2 events/h of sleep (n/h), P = .01) and apnea index (AI) (-6.6 +/- 3.0 n/h, P = .04) during NREM sleep were lowered by C and, to a lesser extent, by P (-5.9 +/- 3.2 n/h, P = .07 and -5.0 +/- 3.6 n/h, P = .18, respectively). The effect on AI and hypopnea index (HI) during REM sleep was not significant for C (-5.9 +/- 3.4 and 0.1 +/- 2.0, NS, respectively) and P (-2.6 +/- 3.9 and 1.6 +/- 2.0, NS, respectively). There was a significant linear correlation between the change in REM systolic BP and the change in REM AI (r = 0.28, P = .04); the mean BP change correlated negatively with the change in HI (-0.28, P = .04). During NREM sleep there was no significant correlation between changes in BP and the treatment effects on sleep apnea activity. Blood pressure reduction after short-term antihypertensive treatment did not affect sleep disordered breathing during NREM sleep. Reduced BP was associated with a weak reduction of AI and a slight increase of HI during REM sleep. It appears that elevated BP contributes only marginally to sleep apnea severity in hypertensive patients with obstructive sleep apnea.