MMP9 and obstructive sleep apnea syndrome: Serum levels of MMP-8 and MMP-9 markedly decreased at the 2-month control visit as compared to those at the time of OSA diagnosis (146 (79–237 [95% CI 85–217]) vs. 287 (170–560 [95% CI 226–403]) pg/mL at baseline, p = 0.028 and 10.1 (7.1–14.1 [95% CI 7.8–13.2]) vs. 12.7 (10.4–15.6 [95% CI 10.8–15.0]) ng/mL at baseline, p = 0.029, respectively; Fig. 2), while the level of the remaining analytes did not markedly change during this early period of CPAP treatment.