Appel L J, Hebert P R, Cohen J D, Obarzanek E, Yamamoto M, Buring J, Stevens V, Kirchner K, Borhani N O
Johns Hopkins University School of Medicine, Welch Center for Prevention, Epidemiology and Clinical Research, Baltimore, MD 21205-2223, USA.
Ann Epidemiol. 1995 Mar;5(2):149-55. doi: 10.1016/1047-2797(94)00059-3.
Phase II of the Trials of Hypertension Prevention (TOHP II) is a multicenter, controlled clinical trial designed to test whether weight loss, a reduced sodium intake, or a combination of weight loss and a reduced sodium intake will lower blood pressure (BP) and prevent the occurrence of hypertension. The study population consists of middle-aged, moderately overweight individuals with a diastolic BP between 83 and 89 mm Hg. Of the 2382 randomized participants, 816 (34%) are female and 494 (21%) are from a racial or ethnic minority background. At baseline, mean dietary intakes of sodium, based on measurements of 24-hour urinary excretion, were 199 mmol/d in men and 154 mmol/d in women. The average body mass index was 30.9 kg/m2. Across the four randomized groups, there was no substantial imbalance in the distribution of baseline variables; however, the mean age in the four groups was slightly but significantly different (range: 43.2 to 44.2 years, P = 0.02). A comparison of baseline characteristics of TOHP II participants with those of participants in three other primary prevention trials reveals a high level of mean dietary sodium intake in each study. Data reported in this article indicate that any subsequent differences in BP among the randomized groups are unlikely to result from maldistribution of known confounding variables at baseline. Finally, because of the high prevalence of overweight and excessive sodium intake in the United States, results from TOHP II should be broadly applicable to the general population.
高血压预防试验（TOHP II）的第二阶段是一项多中心对照临床试验，旨在测试体重减轻、钠摄入量减少，或体重减轻与钠摄入量减少相结合是否会降低血压（BP）并预防高血压的发生。研究人群包括中年、中度超重且舒张压在83至89毫米汞柱之间的个体。在2382名随机分组的参与者中，816名（34%）为女性，494名（21%）来自种族或少数民族背景。在基线时，根据24小时尿排泄量测量，男性的平均钠膳食摄入量为199毫摩尔/天，女性为154毫摩尔/天。平均体重指数为30.9千克/平方米。在四个随机分组中，基线变量的分布没有实质性不平衡；然而，四组的平均年龄略有差异但具有统计学意义（范围：43.2至44.2岁，P = 0.02）。将TOHP II参与者的基线特征与其他三项一级预防试验的参与者进行比较，发现每项研究中的平均膳食钠摄入量都很高。本文报告的数据表明，随机分组之间随后出现的血压差异不太可能是由于基线时已知混杂变量的分布不均所致。最后，由于美国超重和钠摄入过量的患病率很高，TOHP II的结果应该广泛适用于一般人群。
