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Hypertensive and Normal Pregnancy--Calcium Metabolism and Renin-Angiotensin - SCOR in Hypertension

Primary Purpose

Cardiovascular Diseases, Heart Diseases, Hypertension

Status
Completed
Phase
Locations
Study Type
Observational
Intervention
Sponsored by
National Heart, Lung, and Blood Institute (NHLBI)
About
Eligibility
Locations
Outcomes
Full info

About this trial

This is an observational trial for Cardiovascular Diseases

Eligibility Criteria

undefined - 100 Years (Child, Adult, Older Adult)MaleDoes not accept healthy volunteers

No eligibility criteria

Sites / Locations

    Outcomes

    Primary Outcome Measures

    Secondary Outcome Measures

    Full Information

    First Posted
    May 25, 2000
    Last Updated
    May 12, 2016
    Sponsor
    National Heart, Lung, and Blood Institute (NHLBI)
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    1. Study Identification

    Unique Protocol Identification Number
    NCT00005456
    Brief Title
    Hypertensive and Normal Pregnancy--Calcium Metabolism and Renin-Angiotensin - SCOR in Hypertension
    Study Type
    Observational

    2. Study Status

    Record Verification Date
    March 2005
    Overall Recruitment Status
    Completed
    Study Start Date
    December 1990 (undefined)
    Primary Completion Date
    undefined (undefined)
    Study Completion Date
    November 1995 (Actual)

    3. Sponsor/Collaborators

    Name of the Sponsor
    National Heart, Lung, and Blood Institute (NHLBI)

    4. Oversight

    5. Study Description

    Brief Summary
    To study calcium metabolism and the renin-angiotensin system in hypertensive and normal pregnancy.
    Detailed Description
    BACKGROUND: 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. DESIGN NARRATIVE: 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.

    6. Conditions and Keywords

    Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
    Cardiovascular Diseases, Heart Diseases, Hypertension, Eclampsia, Pre-Eclampsia

    7. Study Design

    10. Eligibility

    Sex
    Male
    Maximum Age & Unit of Time
    100 Years
    Accepts Healthy Volunteers
    No
    Eligibility Criteria
    No eligibility criteria
    Overall Study Officials:
    First Name & Middle Initial & Last Name & Degree
    Phyllis August
    Organizational Affiliation
    Weill Medical College of Cornell University

    12. IPD Sharing Statement

    Citations:
    PubMed Identifier
    8039849
    Citation
    Blank SG, Helseth G, Pickering TG, West JE, August P. How should diastolic blood pressure be defined during pregnancy? Hypertension. 1994 Aug;24(2):234-40. doi: 10.1161/01.hyp.24.2.234.
    Results Reference
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    PubMed Identifier
    8027239
    Citation
    Sealey JE, Itskovitz-Eldor J, Rubattu S, James GD, August P, Thaler I, Levron J, Laragh JH. Estradiol- and progesterone-related increases in the renin-aldosterone system: studies during ovarian stimulation and early pregnancy. J Clin Endocrinol Metab. 1994 Jul;79(1):258-64. doi: 10.1210/jcem.79.1.8027239.
    Results Reference
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    PubMed Identifier
    9541274
    Citation
    Baylis C, Beinder E, Suto T, August P. Recent insights into the roles of nitric oxide and renin-angiotensin in the pathophysiology of preeclamptic pregnancy. Semin Nephrol. 1998 Mar;18(2):208-30.
    Results Reference
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    PubMed Identifier
    8588110
    Citation
    Hojo M, August P. Calcium metabolism in normal and hypertensive pregnancy. Semin Nephrol. 1995 Nov;15(6):504-11.
    Results Reference
    background
    PubMed Identifier
    7707813
    Citation
    August P, Mueller FB, Sealey JE, Edersheim TG. Role of renin-angiotensin system in blood pressure regulation in pregnancy. Lancet. 1995 Apr 8;345(8954):896-7. doi: 10.1016/s0140-6736(95)90012-8.
    Results Reference
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    Hypertensive and Normal Pregnancy--Calcium Metabolism and Renin-Angiotensin - SCOR in Hypertension

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