Chest
Original ResearchSleep MedicineObstructive Sleep Apnea and Resistant Hypertension: A Case-Control Study
Section snippets
Materials and Methods
This case-control study was performed in the hypertension clinic of the Hospital de Clínicas de Porto Alegre (Porto Alegre, RS, Brazil), where a cohort study of patients with hypertension is underway.101112 Case patients and control subjects were consecutively enrolled between March 2004 and June 2006. Adult patients of both genders who were 40 to 70 years of age and had body mass index (BMI) values ranging from 25 to 40 kg/m2 were invited to participate. The Institutional Review Board approved
Results
In total, 143 consecutive patients who fulfilled the criteria for enrollment were invited to participate. Ten patients refused to participate. Of the 133 patients who signed the inform consent form, 7 patients had polysomnography or ABPM measures inadequate for analysis, leaving 126 patients for effective analysis. Characteristics of case patients and control subjects are displayed in Table 1. Gender, age, and BMI were comparable in the two groups. BP measured at office and by ABPM was
Discussion
This is the first controlled study to show an independent association between OSAS and resistant hypertension. The odds ratio close to 5.0 is impressive and strengthens the concept that OSAS is a major risk factor of resistant hypertension.
The risk of OSAS for hypertension has been demonstrated in several studies.151617 The association of OSAS with resistant hypertension, however, was less investigated to date. In a case series,9 OSAS was diagnosed in 83% of patients with resistant
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Cited by (0)
This study was funded by Conselho Nacional de Pesquisa, Fundação de Amparo î Pesquisa do Estado do Rio Grande do Sul, and Fundo de Incentivo î Pesquisa do Hospital de Clínicas de Porto Alegre.
This article is not under consideration elsewhere, and the authors have no potential conflicts of interest regarding this article.