PURPOSE:OSA is an independent risk factor for arterial hypertension. Few studies have analysed the role of CPAP treatment upon BP control in hypertensive patients (pts); however the results have not been conclusive. Objectives: To evaluate the effect of APAP therapy on ambulatory BP in pts with OSA and hypertension.
METHODS:We conducted a prospective follow-up study (2 months) in 30 pts with OSA and moderate to severe hypertension under antihypertensive treatment. 24h ambulatory BP monitoring was measured at baseline and after APAP.
RESULTS:Patients had a mean age of 51.2±8.1years, a mean body mass index of 34.1±5.2 kg/m2, a mean apnea-hypopnea index of 51.3±28.8/h. Mean 24h systolic and diastolic BP (SBP and DBP, respectively) were 133.4+7.4 and 82.0+6.4 mmHg. 15 pts presented a non dipper nocturnal pressure pattern. Mean APAP compliance was 6.6+0.9 h/d. After 2 months of APAP, there was a significant decrease in 24h SBP (-4.0+7.9 mmHg;p=0.009), daytime SBP (-4.3+8.8 mmHg;p=0.01), nightime SBP(-5.1+9.0 mmHg;p=0.005), 24h DBP (-2.7+5.8 mmHg;p=0.016) and daytime DBP(-3.2+6.3 mmHg;p=0.009). There was no significant reduction in nightime DBP (-2.5+7.0 mmHg;NS). The normal circadian dipper pattern was not restored in non dipper pts.
CONCLUSION:These results demonstrate that APAP treatment significantly reduces systolic and diastolic blood pressure in patients with OSA and moderate to severe hypertension. This blood pressure decrease could be one of the mechanisms associated with a potencial reduction in cardiovascular mortality and morbidity in OSA patients treated with CPAP. Funded by: Feder/POCI/FCT/Centro de Estudos de Patologia Respiratória.
CLINICAL IMPLICATIONS:Our results show the BP-lowering effects of APAP therapy for OSA and suggest that potential improvements in BP could be added to the long list of motivating factors for patients to pursue APAP therapy.
DISCLOSURE:Paula Pinto, No Financial Disclosure Information; No Product/Research Disclosure Information