β-受体阻滞剂对血小板凝聚性近日节律的影响

Effects of beta-blockers on the circadian rhythm of platelet aggregability

目的 探讨冠心病患者血小板凝聚力的昼夜变化节律以及 β 受体阻滞剂对其的影响。方法 共入选 4 6例冠心病患者 ,其中男性 33例 ,女性 13例 ;年龄 32～ 6 7(49± 9)岁。在常规基础治疗2周后 ,抽采血样 (4h一次 ,2 4h内共 6次 )测定其血小板聚集力。然后给患者服用美托洛尔 (2 5mg ,每日 2次 ) ,2周后重复测定血小板聚集功能。应用余弦拟合法分析其昼夜分布曲线的近日节律。结果 统计分析表明 ,美托洛尔治疗前后患者血小板凝聚力的昼夜分布均表现为近日节律。美托洛尔治疗对血小板凝聚力的 2 4h中值 (6 4 0 6 5 3对 6 1 6 6 3 0 ,P >0 0 5 )与峰值相位 (10 1° 98°对 115° 116°,P >0 0 5 )无显著影响 ,但显著降低了其峰值水平 (振幅 10 0 9 9对 4 0 5 2 ,P <0 0 0 1)。结论 冠心病患者血小板凝聚力存在近日节律 ,美托洛尔治疗对其昼夜平均水平无显著影响 ,但可有效抑制清晨觉醒后数小时内血小板凝聚性的迅速升高现象 ,可能有助于降低这一时段内缺血性心脏事件发作的危险性。

Objective To evaluate the effects of beta blockers on the circadian rhythm of platelet aggregability Methods Forty six patients with stable angina were included Platelet aggregability(Born′s method, every 4 hours within the 24 hour day)was measured before and 2 weeks after metopranolol administration (25mg, bid), and cosinor fitting method was adopted in this study to analyze diurnal rhythms of the indices Results We found that, metopranolol did not change the mid values of cosinor curve on platelet aggregability, but it did truncate its peak value during the first hours after waking up Conclusion Treatment with beta blockers can reduce the cardiac event risks during the early morning by decrease the higher aggregability of platelet in this time interval, although the average aggregability of 24 hours could not be affected