Cardiovascular DiseasesNCT00005456
Hypertensive and Normal Pregnancy--Calcium Metabolism and Renin-Angiotensin - SCOR in Hypertension
An observational study of Cardiovascular Diseases and Heart Diseases, run by National Heart, Lung, and Blood Institute (NHLBI).
Trial summary
To study calcium metabolism and the renin-angiotensin system in hypertensive and normal pregnancy. Read more about this study
- Who is it for?
- Ages Up to 100 years, men only
- Conditions the study is for
- Cardiovascular Diseases, Heart Diseases, Hypertension
- How many people
- Not given
- Where
- No sites listed yet
- Study dates
- Dec 1990to Nov 1995
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Up to 100 years
- Men only
- No healthy volunteers
- Child, Adult, Older adult
No eligibility criteria
About this study
To study calcium metabolism and the renin-angiotensin system in hypertensive and normal pregnancy.
Read the 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.
- Conditions
- Cardiovascular Diseases, Heart Diseases, Hypertension, Eclampsia, Pre-Eclampsia
- Medical subject headings
- Cardiovascular Diseases, Heart Diseases, Hypertension, Eclampsia, Pre-Eclampsia
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 May 2000 (estimated)
- Study startDec 1990
- Study completionNov 1995
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Cardiovascular DiseasesStudies of the same condition, open and under way.
- More trials run by National Heart, Lung, and Blood Institute (NHLBI)The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Investigators
- Phyllis August, Weill Medical College of Cornell University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00005456
- Sponsor's protocol ID
- 4900
- Other IDs
- P50HL018323
- Status last verified
- Mar 2005
- First submitted
- 25 May 2000
- Last updated
- 13 May 2016
- Results posted
- No
Publications
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.
PubMed 8039849Sealey 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.
PubMed 8027239Baylis 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.
PubMed 9541274Hojo M, August P. Calcium metabolism in normal and hypertensive pregnancy. Semin Nephrol. 1995 Nov;15(6):504-11.
PubMed 8588110August 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.
PubMed 7707813
Study at a glance
From the registry record, last updated by the sponsor on 13 May 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hypertensive and Normal Pregnancy--Calcium Metabolism and Renin-Angiotensin - SCOR in Hypertension
- ClinicalTrials.gov ID
- NCT00005456
- Acronym / sponsor ID
- 4900
- Conditions
- Cardiovascular Diseases, Heart Diseases, Hypertension, Eclampsia, Pre-Eclampsia
- Study type
- Observational
- Recruitment status
- Completed
- Lead sponsor
- National Heart, Lung, and Blood Institute (NHLBI)US National Institutes of Health
- Study start
- Dec 1990
- Study completion
- Nov 1995 (actual)
- First posted
- 26 May 2000 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
Who may qualify
- Ages
- Up to 100 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Not reported in the source record.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 May 2016.
- Background: PubMed 8039849Blank 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.
- Background: PubMed 8027239Sealey 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.
- Background: PubMed 9541274Baylis 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.
- Background: PubMed 8588110Hojo M, August P. Calcium metabolism in normal and hypertensive pregnancy. Semin Nephrol. 1995 Nov;15(6):504-11.
- Background: PubMed 7707813August 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Phyllis August
Weill Medical College of Cornell University
Questions about this trial
What is this clinical trial studying?
An observational study of Cardiovascular Diseases and Heart Diseases, run by National Heart, Lung, and Blood Institute (NHLBI).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 May 2016. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00005456, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 May 2016.