Hypertensive and Normal Pregnancy--Calcium Metabolism and Renin-Angiotensin - SCOR in Hypertension
|ClinicalTrials.gov Identifier: NCT00005456|
Recruitment Status : Completed
First Posted : May 26, 2000
Last Update Posted : May 13, 2016
|First Submitted Date||May 25, 2000|
|First Posted Date||May 26, 2000|
|Last Update Posted Date||May 13, 2016|
|Start Date||December 1990|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures||Not Provided|
|Original Primary Outcome Measures||Not Provided|
|Change History||Complete list of historical versions of study NCT00005456 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures||Not Provided|
|Original Secondary Outcome Measures||Not Provided|
|Current Other Outcome Measures||Not Provided|
|Original Other Outcome Measures||Not Provided|
|Brief Title||Hypertensive and Normal Pregnancy--Calcium Metabolism and Renin-Angiotensin - SCOR in Hypertension|
|Official Title||Not Provided|
|Brief Summary||To study calcium metabolism and the renin-angiotensin system in hypertensive and normal pregnancy.|
Beginning in Fiscal Year 1975, the multidisciplinary SCOR examined causes, consequences, and treatments of human hypertension. A central theme was the renal basis for human hypertension. The subproject on calcium metabolism and the renin-angiotensin system in hypertensive and normal pregnancy began in December, 1990.
A longitudinal study was performed on normal pregnant women and women with chronic hypertension who had a high incidence of superimposed preeclampsia. In a previous study, the investigators had demonstrated that preeclampsia was associated with reduced urinary excretion of calcium and with lower plasma renin activity (PRA) compared with normal pregnancy. The goal of the investigators was to identify the metabolic and cellular basis for these alterations in calcium homeostasis and in the renin angiotensin system. They tested two hypotheses. The first hypothesis was that diminished placental and/or renal production of 1,25-dihydroxyvitamin D, leading to lower serum calcium, higher parathyroid hormone, and increased renal tubular reabsorption of calcium, was the metabolic basis for hypocalciuria in preeclampsia. The second hypothesis was that lower PRA in preeclampsia was due to systemic and renal vasoconstriction with hypertension and diminished natriuresis.
Serial measurements of 1,25-dihydroxyvitamin D, parathyroid hormone, serum ionized calcium, PRA, estradiol and progesterone, and urinary calcium and electrolytes were obtained, particularly at the onset of preeclampsia. Acute renal hemodynamic studies were also performed in women with preeclampsia and in gestational age matched normals. The studies investigated the relationships among glomerular filtration rate, renal blood flow, parathyroid hormone, vitamin D, atrial natriuretic factor, renin, estradiol and progesterone, and sodium and calcium excretion during infusion of inulin and PAH with either saline or calcium chloride.
Intracellular free calcium concentration in platelets and lymphocytes of pregnant women participating in longitudinal and acute renal hemodynamic studies were also measured. Basal and stimulated (with angiotensin II, ionomycin and thrombin), intracellular free calcium concentrations were compared in normal and hypertensive pregnant women and correlated with calcium regulatory hormones, plasma renin activity and hypertension.
The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.
|Study Design||Not Provided|
|Target Follow-Up Duration||Not Provided|
|Sampling Method||Not Provided|
|Study Population||Not Provided|
|Study Groups/Cohorts||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Completion Date||November 1995|
|Primary Completion Date||Not Provided|
|Eligibility Criteria||No eligibility criteria|
|Ages||up to 100 Years (Child, Adult, Senior)|
|Accepts Healthy Volunteers||No|
|Contacts||Contact information is only displayed when the study is recruiting subjects|
|Listed Location Countries||Not Provided|
|Removed Location Countries|
|Other Study ID Numbers||4900
P50HL018323 ( U.S. NIH Grant/Contract )
|Has Data Monitoring Committee||Not Provided|
|U.S. FDA-regulated Product||Not Provided|
|IPD Sharing Statement||Not Provided|
|Responsible Party||Not Provided|
|Study Sponsor||National Heart, Lung, and Blood Institute (NHLBI)|
|PRS Account||National Heart, Lung, and Blood Institute (NHLBI)|
|Verification Date||March 2005|