Blood pressure after modified uvulopalatopharyngoplasty: results from the SKUP randomized controlled trial.

OBJECTIVE

Obstructive sleep apnea (OSA) is a risk factor for hypertension. The SKUP study showed that modified uvulopalatopharyngoplasty (UPPP) significantly improved nocturnal respiration, sleepiness, and quality of life. The aim of this study was to evaluate the impact of surgery on blood pressure in patients with OSA.

METHODS

We used a single-center randomized controlled trial to compare modified UPPP with controls at baseline and after six months. The controls received delayed surgery with an additional six-month follow-up. All operated patients also had a follow-up after 24 months. Polysomnography was performed at each follow-up, with systolic and diastolic blood pressure (SBP, DBP) measured the morning after.

RESULTS

A total of 65 patients were randomized to intervention (n = 32) or control (n = 33). At follow-up (n = 61/65, 94%), there were significant differences between the groups in both mean SBP (-9.4 mmHg [95% CI: -17.9, -0.83], p < 0.05) and mean DBP (-6.4 mmHg [95% CI: -12.8, -0.04], p < 0.05), in favor of UPPP. Blood pressure and respiratory parameters at follow-up correlated. The analyses of all operated patients showed a significant decrease in mean (SD) blood pressure after six months (n = 49/65, 75%; SBP: -4.5 [9.0], p = 0.001; DBP: -2.2 [6.6], p = 0.030) as well as after 24 months (n = 35/65, 54%; SBP: -8.9 [11.5], p < 0.0001; DBP: -4.2 [9.4], p = 0.012).

CONCLUSIONS

Blood pressure was significantly decreased after surgery, indicating that modified UPPP decreases the blood pressure, in a selected group of patients with moderate to severe OSA. The long-term effect was also significant, but these results are uncertain due to a high proportion of missing values.

TRIAL REGISTRATION NUMBER

NCT01659671.