Kawano Y, Tochikubo O, Watanabe Y, Miyajima E, Ishii M
Department of Cardiology, Nanasawa Rehabilitation Hospital, Atsugi, Japan.
Hypertens Res. 1997 Sep;20(3):149-56. doi: 10.1291/hypres.20.149.
To investigate the effects of doxazosin on blood pressure and sympathetic nervous activity, we analyzed the circadian variation of blood pressure and the power spectrum of R-R intervals using an ambulatory multibiomedical monitoring system (TM2425) in 10 untreated outpatients with essential hypertension. After a 2-wk placebo period (P-period), we administered 1 to 4 mg of doxazosin mesilate to the patients for 2 to 6 wk (T-period). We measured systolic and diastolic blood pressure (SBP, DBP), heart rate, R-R intervals, posture, and activity with the use of TM2425. Power spectral analysis of R-R intervals was used to calculate the ratio of low to high frequency components (LF/HF). The values were compared between the P-period and T-period. Although daytime blood pressure significantly decreased during the T-period (SBP, 148.1 +/- 5.9 vs. 130.3 +/- 4.4 mmHg; DBP, 92.3 +/- 3.2 vs. 83.6 +/- 2.6 mmHg, p < 0.01), nighttime DBP did not. The LF/HF of R-R intervals in the daytime (5.8 +/- 2.0 vs. 4.9 +/- 1.2, p < 0.01) and the morning rise in blood pressure also decreased significantly (SBP, 17.5 +/- 9.4 vs. 12.1 +/- 6.5 mmHg; DBP, 12.5 +/- 6.5 vs. 8.3 +/- 5.3 mmHg, p < 0.05). We conclude that doxazosin may suppress the morning rise in blood pressure in association with a decrease in sympathetic nervous activity.
为研究多沙唑嗪对血压及交感神经活动的影响，我们使用动态多生物医学监测系统（TM2425）对10例未经治疗的原发性高血压门诊患者的血压昼夜变化及R-R间期功率谱进行了分析。在为期2周的安慰剂期（P期）后，我们给予患者1至4毫克甲磺酸多沙唑嗪，持续2至6周（T期）。我们使用TM2425测量收缩压和舒张压（SBP、DBP）、心率、R-R间期、体位及活动情况。通过对R-R间期进行功率谱分析来计算低频与高频成分的比值（LF/HF）。对P期和T期的值进行比较。虽然T期白天血压显著下降（SBP：148.1±5.9 vs. 130.3±4.4 mmHg；DBP：92.3±3.2 vs. 83.6±2.6 mmHg，p<0.01），但夜间DBP未下降。白天R-R间期的LF/HF（5.8±2.0 vs. 4.9±1.2，p<0.01）以及血压的晨峰也显著降低（SBP：17.5±9.4 vs. 12.1±6.5 mmHg；DBP：12.5±6.5 vs. 8.3±5.3 mmHg，p<0.05）。我们得出结论，多沙唑嗪可能通过降低交感神经活动来抑制血压晨峰。
