Oral Calcium in Pregnant Women With Hypertension

NCT ID: NCT00000543

Last Updated: 2016-05-13

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

PHASE2

Study Classification

INTERVENTIONAL

Study Start Date

1993-08-31

Study Completion Date

1999-07-31

Brief Summary

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To determine of providing calcium supplementation to women with pre-existing hypertension reduces the level of blood pressure, requirement for antihypertensive drugs, and incidence of pre-eclampsia.

Detailed Description

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BACKGROUND:

Maternal and fetal complications are more likely to occur in pregnant women with preexisting hypertension. Alterations in calcium metabolism, the renin angiotensin system, and intracellular free calcium concentration have been identified in this high risk population. The beneficial effects of calcium supplementation on blood pressure and the incidence of superimposed pre-eclampsia may be due to correction of the hormonal and cellular basis for vasoconstriction. The trial sought to prove that oral calcium lowered parathyroid hormone, reduced intracellular free calcium, and decreased vascular endothelin production, resulting in vasodilation and compensatory stimulation of the renin-angiotensin system.

DESIGN NARRATIVE:

Randomized. Double blind. In this observational study, subjects were assigned to two grams of supplemental elemental calcium or to placebo at 13 to 15 weeks gestation. The trial determined the effect of oral calcium supplementation on: the level of blood pressure; the need for antihypertensive drugs; forearm and peripheral vascular resistance; the incidence of maternal complications, including pre-eclampsia and eclampsia; and plasma levels of vitamin D3, ionized calcium, parathyroid, renin activity, angiotensin II, endothelin, nitrate/nitrite, prostacyclins, and intracellular calcium concentrations in lymphocytes and platelets. These variables were measured prior to randomization and every two months throughout pregnancy and the postpartum. Support ended in July 1999.

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

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Cardiovascular Diseases Heart Diseases Hypertension Pre-Eclampsia Pregnancy Toxemias Vascular Diseases

Study Design

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Allocation Method

RANDOMIZED

Primary Study Purpose

PREVENTION

Blinding Strategy

DOUBLE

Interventions

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dietary supplements

Intervention Type BEHAVIORAL

calcium

Intervention Type DRUG

Eligibility Criteria

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Inclusion Criteria

Pregnant women with chronic hypertension.
Minimum Eligible Age

18 Years

Maximum Eligible Age

40 Years

Eligible Sex

FEMALE

Accepts Healthy Volunteers

No

Sponsors

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National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role lead

References

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Hojo M, August P. Calcium metabolism in normal and hypertensive pregnancy. Semin Nephrol. 1995 Nov;15(6):504-11.

Reference Type BACKGROUND
PMID: 8588110 (View on PubMed)

Hojo M, Suthanthiran M, Helseth G, August P. Lymphocyte intracellular free calcium concentration is increased in preeclampsia. Am J Obstet Gynecol. 1999 May;180(5):1209-14. doi: 10.1016/s0002-9378(99)70618-6.

Reference Type BACKGROUND
PMID: 10329879 (View on PubMed)

Curnow KM, Pham T, August P. The L10F mutation of angiotensinogen is rare in pre-eclampsia. J Hypertens. 2000 Feb;18(2):173-8. doi: 10.1097/00004872-200018020-00007.

Reference Type BACKGROUND
PMID: 10694185 (View on PubMed)

Other Identifiers

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R01HL048846

Identifier Type: NIH

Identifier Source: secondary_id

View Link

86

Identifier Type: -

Identifier Source: org_study_id

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