Rutter M K, McComb J M, Brady S, Marshall S M
Department of Medicine, University of Newcastle upon Tyne, United Kingdom.
Am J Cardiol. 1999 Jan 1;83(1):27-31. doi: 10.1016/s0002-9149(98)00777-2.
Microalbuminuria is an increase in urinary albumin not detected by conventional dipstick testing and is present in 20% of patients with non-insulin-dependent diabetes mellitus (NIDDM). Mortality in NIDDM patients with microalbuminuria is 60% at 8 years and is mainly due to cardiovascular disease. Because many deaths occur without warning symptoms, we have compared the prevalence and severity of silent myocardial ischemia in asymptomatic NIDDM patients with and without microalbuminuria. We have performed a cross-sectional, case-control study of asymptomatic NIDDM patients attending hospital diabetes clinics. Forty-three patients with microalbuminuria were matched for age, gender, diabetes duration, and smoking status with 43 normoalbuminuric patients. A symptom-limited exercise stress test was performed and reported blind to patient status. The degree of electrocardiographic ST-segment depression, exercise time, work performed, and maximum heart rate with exercise were recorded. Patients with microalbuminuria had a higher prevalence of ischemic response (>1 mm ST depression) (65% vs 40%, p = 0.016), reduced total exercise time (5 vs 7 minutes, p <0.001), reduced work (6 vs 8 METs, p <0.001), and reduced age-predicted maximum heart rate (94% vs 101%, p = 0.004). In multiple logistic regression, albumin excretion rate was shown to be the strongest independent predictor of ischemic response (p = 0.03). Silent myocardial ischemia is common in asymptomatic NIDDM patients but is more common in those with microalbuminuria. In these subjects, the higher prevalence of ischemic response at low workloads suggests a higher probability of future coronary events, and possibly a higher probability of potentially treatable coronary artery disease.
微量白蛋白尿是指通过传统试纸检测未发现的尿白蛋白增加，在20%的非胰岛素依赖型糖尿病（NIDDM）患者中存在。患有微量白蛋白尿的NIDDM患者8年时的死亡率为60%，主要归因于心血管疾病。由于许多死亡发生时没有预警症状，我们比较了有无微量白蛋白尿的无症状NIDDM患者中无症状心肌缺血的患病率和严重程度。我们对到医院糖尿病门诊就诊的无症状NIDDM患者进行了一项横断面病例对照研究。43例微量白蛋白尿患者在年龄、性别、糖尿病病程和吸烟状况方面与43例尿白蛋白正常的患者相匹配。进行了症状限制性运动应激试验，并在对患者状况不知情的情况下进行报告。记录心电图ST段压低程度、运动时间、做功量和运动时的最大心率。微量白蛋白尿患者缺血反应（ST段压低>1mm）的患病率更高（65%对40%，p = 0.016），总运动时间缩短（5分钟对7分钟，p<0.001），做功量减少（6梅脱对8梅脱，p<0.001），年龄预测的最大心率降低（94%对101%，p = 0.004）。在多因素逻辑回归中，白蛋白排泄率被证明是缺血反应最强的独立预测因素（p = 0.03）。无症状心肌缺血在无症状NIDDM患者中很常见，但在有微量白蛋白尿的患者中更常见。在这些受试者中，低负荷下缺血反应的较高患病率表明未来发生冠状动脉事件的可能性更高，可能患有潜在可治疗的冠状动脉疾病的可能性也更高。
