Textor Stephen C, Taler Sandra J, Larson Timothy S, Prieto Mikel, Griffin Matthew, Gloor James, Nyberg Scott, Velosa Jorge, Schwab Thomas, Stegall Mark
Department of Internal Medicine, Divisions of Hypertension and Nephrology, Mayo Clinic, Rochester, Minnesota, USA.
J Am Soc Nephrol. 2003 Aug;14(8):2159-67. doi: 10.1097/01.asn.0000077346.92039.9c.
With more patients reaching end-stage renal disease, the demand for living kidney donation is increasing rapidly. Many potential donors are now in older age groups. The effects of increasing BP with age and the measurement criteria for hypertension in this group are not well defined. A total of 238 potential donors between 18 and 72 yr of age were prospectively studied, with a comparison of "clinic" BP values measured in the outpatient clinic with an oscillometric recorder (Dinamap; Critikon), ambulatory BP monitoring (ABPM) findings, and standardized BP values determined by nurses using American Heart Association criteria. Renal function was evaluated on the basis of iothalamate clearance (GFR) and urinary protein and microalbumin excretion. Ninety-six percent of subjects were Caucasian. All subjects exhibited normal GFR and urinary protein excretion. Three age groups were defined (group I, </=35 yr, n = 64; group II, 36 to 49 yr, n = 109; group III, >/= 50 yr, n = 65). BP increased with age, as determined with all methods. Subjects >/= 50 yr of age exhibited the highest clinic readings (145 +/- 2/83 +/- 1 mmHg, compared with 129 +/- 2/76 +/- 1 mmHg for group I, P < 0.01). Awake ABPM and nurse-determined BP measurements were lower than clinic readings, including those for group III (131 +/- 2/80 +/- 1 mmHg, compared with 145 +/- 2/83 +/- 1 mmHg in the clinic, P < 0.001). With the use of systolic BP values of >140 mmHg and/or diastolic BP values of >90 mmHg, 36.7% of subjects were initially considered hypertensive; this proportion decreased to 11% overall with awake ABPM findings (>135/85 mmHg). Measurement variability (SD in ABPM) and the effects of misclassification were greatest for donors >/= 50 yr of age. Multivariate regression indicated that GFR of both donors and recipients decreased with age, but regression identified no independent effect of BP. Recipient outcomes for up to 2 yr were equally good for donor kidneys considered normotensive or hypertensive on the basis of clinic BP measurements. These data indicate that higher arterial BP with age can lead to misclassification of many older living kidney donors. Sixty-two subjects with excellent kidney function were misclassified as hypertensive with clinic oscillometric measurements alone. Detailed evaluations of ABPM findings, GFR, and urinary protein levels are warranted for Caucasian subjects with high clinic BP readings who are otherwise suitable potential donors.
随着越来越多的患者进入终末期肾病阶段，活体肾捐赠的需求迅速增长。现在许多潜在捐赠者属于年龄较大的群体。该群体中血压随年龄增长的影响以及高血压的测量标准尚不明确。前瞻性地研究了总共238名年龄在18至72岁之间的潜在捐赠者，比较了门诊使用示波记录仪（Dinamap；Critikon）测量的“诊室”血压值、动态血压监测（ABPM）结果以及护士依据美国心脏协会标准确定的标准化血压值。根据碘肽酸盐清除率（GFR）、尿蛋白和微量白蛋白排泄情况评估肾功能。96%的受试者为白种人。所有受试者的GFR和尿蛋白排泄均正常。定义了三个年龄组（I组，≤35岁，n = 64；II组，36至49岁，n = 109；III组，≥50岁，n = 65）。所有测量方法均显示血压随年龄增长。≥50岁的受试者诊室血压读数最高（145±2/83±1 mmHg，I组为129±2/76±1 mmHg，P < 0.01）。清醒时的ABPM和护士测量的血压值低于诊室读数，包括III组（131±2/80±1 mmHg，诊室为145±2/83±1 mmHg，P < 0.001）。使用收缩压>140 mmHg和/或舒张压>90 mmHg的标准，最初36.7%的受试者被认为患有高血压；根据清醒时ABPM结果（>135/85 mmHg），总体比例降至11%。年龄≥50岁的捐赠者测量变异性（ABPM中的标准差）和错误分类的影响最大。多变量回归表明，捐赠者和接受者的GFR均随年龄下降，但回归分析未发现血压的独立影响。根据诊室血压测量，被认为血压正常或高血压的捐赠者肾脏，其接受者长达2年的预后同样良好。这些数据表明，随着年龄增长动脉血压升高会导致许多老年活体肾捐赠者被错误分类。仅通过诊室示波测量，62名肾功能良好的受试者被错误分类为高血压患者。对于诊室血压读数高但其他方面适合作为潜在捐赠者的白种人受试者，有必要详细评估ABPM结果、GFR和尿蛋白水平。
