Sleep apnea syndrome: A possible contributing factor to resistant

Abstract

Study Objectives: There is evidence supporting an association between sleep apnea and hypertension. However, it is not clear if sleep apnea interteres with the pharmacotherapy of hypertension. To investigate this question, we studied the relationship between the effectiveness of anti-hypertensive treatment in reducing blood pressure, and severity of sleep apnea in a large group of apneic patients referred to a sleep disorders centre at St. Michael's Hospital at the University of Toronto. Design: N/A Setting: N/A Participants: 1485 adult patients with sleep apnea, as defined by the apnea/hypopnea index (AHI) >10 events/hr, were analyzed. There were 393 who reported using anti-hypertensive medications on a regular basis for more than 6 months. One hundred and eighty-three patients were treated "effectively" (i.e. blood pressure lower than 140/90 mm Hg in the morning and in the evening). Seventy-four patients were treated "ineffectively," defined as blood pressure >140/90 mm Hg in the morning or in the evening. Both groups were compared with respect to clinical and demographic data using analysis of covariance with gender, age, body mass index (BMI), and neck circumference (NC) as covariates. Interventions: N/A Measurements and Results: Ineffectively and effectively treated patients were similar in age (57±9) vs. 57±10 years, respectively), and had similar body mass index (33.8±7.4 vs. 33.4±7.3 kg/m2, respectively). However, ineffectively treated patients had significantly higher apnea/hypopnea index (44±29 vs. 33±25 events/hr, p