Original work

Long-term effects of nocturnal continuous positive airway pressure therapy in patients with resistant hypertension and obstructive sleep apnea

Obstructive sleep apnea (OSA) is often linked to high blood pressure and has a particularly high prevalence in patients with resistant hypertension. The effect of continuous positive airway pressure (CPAP) therapy on blood pressure (BP) values has been evaluated in several short-term clinical trials with conflicting results. Our aim was to investigate the role of long-term CPAP treatment in achieving BP control in patients who associate OSA and resistant hypertension. We have included in the study 33 patients with resistant hypertension, diagnosed with OSA in our sleep lab. Data was collected initially and after a mean follow-up period of 4 years. Patients were divided into 2 groups according to the use of CPAP therapy. Patients under CPAP therapy (n=12) exhibited a higher reduction in both systolic and diastolic pressure and BP control was achieved in 75% of cases, while patients without CPAP treatment (n=21) remained with refractory hypertension in proportion of 90.5%. A de-escalation of antihypertensive drug regimen by discontinuation of 1 or more drugs was observed in 41.6% (n=5) of patients from CPAP group and in the other 33.4% (n=4) the medication remained unchanged, but BP control was reached. Using a direct logistic regression model for examining the impact of different confounders on the probability of diagnosis of resistant hypertension at follow-up, the only statistically significant predictor found was the lack of CPAP usage.

Keywords: sleep apnea, resistant hypertension, CPAP therapy, blood pressure control

Article

Long-term gender-specific evolution of blood pressure under CPAP therapy in hypertensive patients with obstructive sleep apnea syndrome

Introduction: Reduction of blood pressure (BP) under CPAP treatment in patients with obstructive sleep apnea syndrome (OSAS) associating hypertension (HT) is controversial and short-term evolution is often measured using the sphygmomanometer.
Purpose: To study the variation in BP (sphygmomanometer and Holter) after 3 and 6 months of CPAP in OSAS patients associating hypertension.
Methods: We applied the exclusion criteria (hypoventilation, respiratory diseases, secondary hypertension, antihypertensive treatment modification during study, non-compliance) on 96 consecutive patients (SPSS 17.0: Chi test, T-test).
Results: 15 hypertensive patients (8.53 years from diagnosis) with OSAS succeeded six months of following: 3 women (20%), 12 men (80%) were comparable as age, body mass index and Epworth score; women had more severe OSAS. Sphygmomanometer measuring in men showed a decrease in systolic BP (SBP) (142±8.9 to 128.7±11,7 mmHg, p=0.005) and diastolic BP (DBP) (82 ±11.9 to 69,1±6,6 mmHg, p=0.040) at three months of treatment. Women had no changes at 3 and 6 months of assessment using the sphygmomanometer. BP Holter showed no significant changes in men; women exhibit a significant increase in maximum DBP/24 hours (104±13.4 to 169.5±27.5 mmHg, p=0.034) and mean daytime DBP/24 hours (100±14.1 to 166±32.5 mmHg, p=0.046) from 3 to 6 months. No group presents dipper status change to 3 or 6 months.
Conclusions: The trend in both groups of increase in BP for 3 to 6 months is explained by the natural evolution of an old HT history. Long time monitoring using Holter device is more accurate in assessing cardiovascular risk.

Keywords: obstructive sleep apnea syndrome, arterial hypertension, CPAP treatment

Article