Background and Objective Obstructive sleep apnoea is an independent risk factor of hypertension. Several recent meta-analyses based on European and Americans have shown a reduction of blood pressure (BP) of about 2 mm Hg with continuous positive airway pressure (CPAP). This lowering of blood pressure is significant in terms of reduction in both cardiovascular and cerebrovascular risk and death. This is a randomised and controlled study to evaluate the effect of CPAP on blood pressure in Chinese cohorts with cardiovascular and cerebrovascular diseases.
Methods Polysomnogram was performed to 45–75 years old patients with cardiovascular and cerebrovascular diseases in China. Forty-four middle-severe OSA patients were enrolled and baseline demographic data as well as sleep study data was recorded in these patients. The subjects were then randomly assigned to receive medical therapy either alone (22 patients) or with the addition of continuous positive airway pressure (22 patients). Daytime blood pressure, heart rate and Epworth score (ESS score) of the two groups was compared after one month follow-up.
Results Twenty-one patients in the CPAP group and 22 control subjects completed the study. Compared with the control group, CPAP treatment markedly reduced the daytime diastolic blood pressure (∆−0.85±4.67 vs ∆−5.09±5.38, respectively, p=0.038), and improvement in ESS scores (∆−0.80±2.16 vs ∆−5.31±2.43, p<0.001). In contrast, there were no significant changes in systolic blood pressure (∆−0.51±5.8 vs ∆−2.82±8.09, p=0.425) and heart rate.
Conclusions Compared with the control group, CPAP treatment for one month was associated with significant reduction in diastolic blood pressure and improvement in ESS score. The reduction of daytime systolic blood pressure did not reach the significant point; however, it was more than 2 mm Hg. In conclusion, CPAP treatment in OSA patients with cardiovascular and cerebrovascular diseases leads to effective reduction in daytime blood pressure, which is significant for reduction of both cardiovascular and cerebrovascular risk and death.