Sanchez-Ramos L, Jones D C, Cullen M T
Department of Obstetrics and Gynecology, University of Florida Health Science Center, Jacksonville.
Obstet Gynecol. 1991 May;77(5):685-8.
Women who develop preeclampsia during pregnancy excrete less calcium than healthy pregnant women. Whether this reduction in calcium excretion precedes or follows hypertension is unknown. We prospectively measured urinary calcium excretion in 103 consecutive nulliparous women at risk for preeclampsia and presenting for prenatal care before 24 weeks' gestation. Serial 24-hour urine specimens were obtained at 10-24 weeks, 25-32 weeks, and 33 weeks to term. After delivery, the charts were reviewed for the presence of preeclampsia and gestational hypertension. At the first collection, patients who later developed preeclampsia excreted less urinary calcium (169 +/- 30 mg/24 hours; mean +/- standard error of the mean) than those who remained normotensive (298 +/- 15 mg/24 hours) (P less than .05); this reduction persisted throughout gestation. Using a receiver operator curve, we calculated a predictive threshold calcium value for hypertension of 195 mg/24 hours. The difference in the incidence of preeclampsia between pregnant women with calcium excretion values at or below 195 mg/24 hours (87%, 95% confidence interval 52-98%) and those with values above that level (2%, confidence interval 0.3-8%) was highly significant (Fisher exact test, P less than .0001). The 95% lower limit of relative risk for preeclampsia in patients with a calcium excretion equal to or below 195 mg/24 hours in the first collection was 9.4. These observations suggest a pathophysiologic role for altered urinary calcium excretion in women with preeclampsia that may contribute to the early identification of patients at risk for this disease.
孕期发生先兆子痫的女性比健康孕妇排泄的钙更少。钙排泄减少是先于还是后于高血压尚不清楚。我们前瞻性地测量了103例连续的初产妇的尿钙排泄情况，这些产妇有发生先兆子痫的风险，且在妊娠24周前前来接受产前检查。在妊娠10 - 24周、25 - 32周和33周直至足月时，连续采集24小时尿液样本。分娩后，查阅病历以确定是否存在先兆子痫和妊娠期高血压。在首次采集时，后来发生先兆子痫的患者尿钙排泄量（169±30mg/24小时；均值±均值标准误）低于血压正常者（298±15mg/24小时）（P<0.05）；这种减少在整个孕期持续存在。使用受试者工作特征曲线，我们计算出高血压的预测阈值钙值为195mg/24小时。钙排泄值在195mg/24小时及以下的孕妇（87%，95%置信区间52 - 98%）与高于该水平的孕妇（2%，置信区间0.3 - 8%）先兆子痫发病率的差异非常显著（Fisher精确检验，P<0.0001）。首次采集时钙排泄量等于或低于195mg/24小时的患者发生先兆子痫的相对风险下限95%为9.4。这些观察结果表明，尿钙排泄改变在先兆子痫女性中具有病理生理作用，这可能有助于早期识别该疾病的高危患者。
