Effect of change in sodium excretion on change in blood pressure corrected for measurement error. The Trials of Hypertension Prevention, Phase I.
Effect of change in sodium excretion on change in blood pressure corrected for measurement error. The Trials of Hypertension Prevention, Phase I.
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DOI：
10.1093/oxfordjournals.aje.a009668
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发表时间：
1998-09
影响因子：
5
通讯作者：
N. Cook;S. Kumanyika;J. Cutler
中科院分区：
文献类型：
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作者：
N. Cook;S. Kumanyika;J. Cutler
血压（BP）和钠排泄的个体内变异性稀释了相关性，并导致低估了剂量-反应关系。作者应用统计学校正技术对1987-1990年进行的高血压预防试验（TOHP）I期数据进行了分析。舒张压正常值偏高（80-89 mmHg）的男性和女性被随机分配到钠减少组（n = 327）或常规护理对照组（n = 417）。使用多变量误差校正，对合并样本中钠和钠/钾比值（Na/K比值）变化对血压变化影响的回归估计值进行了排泄测量值的人内方差和血压的人内协方差校正。估计的横截面可靠性为0.36平方根（钠）和0.42平方根（钠/钾比值）和变化分别为0.31和0.28。校正系数提示收缩压降低4.4 mmHg（95%置信区间（CI）0.1-8.8）和舒张压2.8 mmHg（95% CI -0.2至5.8）钠每减少100 mmol/24小时，Na/K每降低1个单位，收缩压降低3.4 mmHg（95%CI 0.8-6.1），舒张压降低1.7 mmHg（95%CI 0.0-3.5）。这些结果与Intersalt研究的结果相当，表明在18个月内钠变化对血压正常者血压变化的真实影响在未校正的数据中被低估了一半以上。
Intraperson variability in both blood pressure (BP) and sodium excretion dilutes associations and leads to underestimates of the dose-response relation. The authors applied statistical correction techniques to data from the Trials of Hypertension Prevention (TOHP), Phase I, carried out 1987-1990. Men and women with high normal diastolic BP (80-89 mmHg) were randomized to sodium reduction (n = 327) or a usual care comparison group (n = 417). Regression estimates of the effects of change in sodium and sodium/potassium ratio (Na/K ratio) on blood pressure change in the pooled sample were corrected for both the within-person variance of the excretion measures and the within-person covariance with blood pressure using a multivariate error correction. The estimated cross-sectional reliability was 0.36 for square root(Na) and 0.42 for square root(Na/K ratio) and that for change was 0.31 and 0.28, respectively. Corrected coefficients suggested a decrease of 4.4 mmHg in systolic BP (95% confidence interval (CI) 0.1-8.8) and 2.8 mmHg in diastolic BP (95% CI -0.2 to 5.8) per 100 mmol/24 hour reduction in sodium, and of 3.4 mmHg in systolic BP (95% CI 0.8-6.1) and 1.7 mmHg in diastolic BP (95% CI 0.0-3.5) per unit decrease in Na/K. These results are comparable with those from the Intersalt Study, and suggest that the true effect of sodium change on blood pressure change in normotensives over 18 months is underestimated by more than half in uncorrected data.