Non drowsy obstructive sleep apnea as a potential cause of resistant hypertension: a case report

Abstract

Background: Obstructive sleep apnea (OSA) and arterial hypertension (AH) are common and underrecognized medical disorders. OSA is a potential risk factor for the development of AH and/or may act as a factor complicating AH management. The symptoms of excessive daytime sleepiness (EDS) are considered essential for the initiation of continuous positive airway pressure (CPAP) therapy, which is a first line treatment of OSA. The medical literature and practice is controversial about the treatment of people with asymptomatic OSA. Thus, OSA patients without EDS may be left at increased cardiovascular risk.

Case presentation: The report presents a case of 42 year old Asian woman with symptoms of heart failure and angina like chest pain upon admission. She didn't experience symptoms of EDS, and the Epworth Sleepiness Scale was seven points. Snoring was reported on direct questioning. The patient had prior medical history of three unsuccessful pregnancies complicated by gestational AH and preeclampsia with C-section during the last pregnancy. The admission blood pressure (BP) was 200/120 mm Hg. The patients treatment regimen consisted of five hypotensive medications including diuretic. However, a target BP wasn't achieved in about one and half month. The patient was offered to undergo a polysomnography (PSG) study, which she rejected. One month after discharge the PSG study was done, and this showed an apnea-hypopnea index (AHI) of 46 events per hour. CPAP therapy was initiated with a pressure of 11 H₂0 cm. After 2 months of compliant CPAP use, adherence to pharmacologic regimen and lifestyle modifications the patients BP decreased to 134/82 mm Hg.

Conclusions: OSA and AH are common and often underdiagnosed medical disorders independently imposing excessive cardiovascular risk on a diseased subject. When two conditions coexist the cardiovascular risk is likely much greater. This case highlights a possible clinical phenotype of OSA without EDS and its association with resistant AH. Most importantly a good hypotensive response to medical treatment in tandem with CPAP therapy was achieved in this patient. Thus, it is reasonable to include OSA in the differential list of resistant AH, even if EDS is not clinically obvious.

Figure 1

Patients PSG recording.Abbreviations: ECG-electrocardiography, EEG-electroencephalography, EMG-electromyography, EOG-electrooculography, SaO2-oxygen saturation.