Effect of Nocturnal Nasal Continuous Positive Airway Pressure on Blood Pressure in Obstructive Sleep Apnea

Abstract

Abstract-Obstructive sleep apnea (OSA) is a very common risk factor for hypertension, and continuous positive airway pressure (CPAP) has been widely used to treat OSA. We conducted a meta-analysis of randomized, controlled trials to evaluate the effects of CPAP on blood pressure, reported as either a primary or secondary end point, among patients with OSA. Studies were retrieved by searching Medline (January 1980 to July 2006), the Cochrane Database of Systematic Reviews, conference abstracts, and bibliographies of review and original articles. From 255 relevant reports, 16 randomized clinical trials were selected that compared CPAP to control among participants with OSA, had a minimum treatment duration of 2 weeks, and reported blood pressure changes during the intervention or control period. Data on sample size, participant characteristics, study design, intervention methods, duration, and treatment results were independently abstracted by 2 investigators using a standardized protocol. Data from 16 trials representing 818 participants were examined using a random-effects model. Key Words: continuous positive airway pressure Ⅲ meta-analysis Ⅲ randomized, controlled trial Ⅲ sleep apnea syndromes Ⅲ blood pressure H ypertension is an important public health challenge worldwide. Its high prevalence and subsequent increased risk for developing cardiovascular diseases including heart attack, stroke, and chronic kidney disease have placed it as the leading risk factor for all-cause mortality and a major cause of life years-adjusted disability. 1 A recent study on the global burden of hypertension found that 26.4% of the adult population in 2000 had hypertension, and 29.2% were projected to have hypertension by the year 2025. This translates to Ϸ972 million persons, 333 million in economically developed countries and 639 million in economically developing countries, with hypertension in 2000. In 2025, 1.56 billion adults are expected to have hypertension. 2 Obstructive sleep apnea (OSA) is a very common risk factor for hypertension. In 2003, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure recognized sleep apnea as a common and identifiable cause of hypertension and suggested blood pressure (BP) screening among patients with OSA. 3 Although the prevalence varies by population and age group, it has been estimated that OSA affects Ϸ24% of middle aged men and 9% of middle-aged women. 4 In addition, the 5-year incidence was recently estimated to be 16% for mild-to-moderate and 7.5% for severe forms of OSA in the adult population. 5 Given the prevalence of OSA and its deleterious consequences, randomized, controlled trials have evaluated the use of continuous positive airway pressure (CPAP) to reduce BP among persons with OSA. Unfortunately, many of these trials were small in sample size and did not have sufficient statistical power to detect a modest but potentially important reduction in BP. We conducted a meta-analysis of randomized, controlled t...

Sleep Apnea, the Risk of Developing Heart Failure, and Potential Benefits of Continuous Positive Airway Pressure (CPAP) Therapy

“…Because it provides symptom relief, CPAP therapy is first‐line therapy for SA, but could theoretically also reduce the negative cardiovascular impacts of SA as it has been found to improve glucose tolerance, reduce endothelial damage, lower blood pressure, and improve cardiac function 6, 7, 8, 9, 10. Consequently, one could hypothesize that CPAP therapy protects patients from developing cardiovascular disease such as HF.…”

“…One study even found an increased risk of incident HF among men with obstructive sleep apnea (OSA) 5. Continuous positive airway pressure (CPAP) therapy is a documented treatment for SA because of symptom relief, but it may also reduce endothelial damage and improve blood pressure, glucose tolerance, and cardiac function in patients with HF 6, 7, 8, 9, 10. However, a direct beneficial effect of CPAP therapy on cardiovascular outcomes has never been established in a controlled setting 11, 12.…”

Avanços recentes do impacto da apneia obstrutiva do sono na hipertensão arterial sistêmica

“…Summarizing these findings, a systematic review 61 and four meta-analyses [62][63][64][65] assessing the impact of CPAP on blood pressure have been published in the past few years. All point to a blood pressure reduction with the use of CPAP.…”

“…In Haentjens et al's study 63 , which analyzed 12 placebocontrolled trials using ABPM for the assessment of blood pressure, there was a reduction by 1.77 and 1.79 mmHg in the mean 24-hour systolic and diastolic blood pressures, respectively. The most recent meta-analysis evaluated 818 patients and showed a reduction by 2.46 mmHg in systolic blood pressure and by 1.83 in diastolic blood pressure after the use of CPAP 65 . We should point out that these levels of blood pressure reduction can account for a long-term reduction of cardiovascular events.…”

“…However, the studies chosen for inclusion in these meta-analyses are subject to criticism; they included normotensive patients, and this may have contributed to the small blood pressure reduction 66 . On the other hand, an important finding of one of the metaanalyses was that the magnitude of blood pressure reduction was directly associated with the number of hours of CPAP use during sleep 65 . Current evidences of the beneficial effects of the treatment of OSA in patients with refractory SH [67][68][69] are even weaker, although recent studies point to a greater blood pressure reduction ( Table 2).…”