ObjectiveTo investigate the effects of continuous positive airway pressure (CPAP) ventilation on blood pressure and related inflammatory factors in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and refractory hypertension, and explore the correlation between respiratory function and related inflammatory factors.MethodsPatients with OSAHS and refractory hypertension who visited Shenzhen Nanshan People’s Hospital between January 2014 and September 2018 were randomly divided into a CPAP group and a control group. The control group received routine treatment. The CPAP group received CPAP on the basis of conventional treatment. Each intervention lasted for 7 days. The changes of systolic and diastolic blood pressure were measured before and after 1, 3, 5, and 7 days, respectively. The respiratory function and related inflammatory factors were measured after 7 days of intervention.ResultsAfter 7 days of treatment in the CPAP group, the levels of apnea hyperpnoea index (AHI), lowest oxygen saturation and oxygen desaturation index were significantly better than those before intervention, with the improvement of respiratory function significantly higher than that of the control group after 7 days. Meanwhile the systolic and diastolic blood pressure levels were significantly lower in the CPAP group than those of the control group at 1, 3, 5, and 7 days, and lower than the pre-intervention after 7 days of intervention. After 7 days of intervention, the inflammatory factors in both groups were significantly improved (all P<0.05). However, the serum levels of high sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and endothelin-1 (ET-1) in the CPAP group were significantly lower than those of the control group after 7 days of treatment (P<0.05). There was a significant positive correlation between AHI level and hs-CRP, IL-6, TNF-α and ET-1 in the CPAP group after intervention (P<0.001).ConclusionsCPAP can significantly improve the blood pressure of patients with OSAHS and refractory hypertension. CPAP may improve the related inflammatory factors by improving the respiratory function of patients, thus reduce the patient’s blood pressure.