Oral Calcium in Pregnant Women With Hypertension

This study has been completed.
Sponsor:
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
ClinicalTrials.gov Identifier:
NCT00000543
First received: October 27, 1999
Last updated: June 23, 2005
Last verified: April 2002
  Purpose

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.


Condition Intervention Phase
Cardiovascular Diseases
Heart Diseases
Hypertension
Pre-Eclampsia
Pregnancy Toxemias
Vascular Diseases
Behavioral: dietary supplements
Drug: calcium
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Masking: Double-Blind
Primary Purpose: Prevention

Resource links provided by NLM:


Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: August 1993
Estimated Study Completion Date: July 1999
Detailed Description:

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.

  Eligibility

Ages Eligible for Study:   18 Years to 40 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Criteria

Pregnant women with chronic hypertension.

  Contacts and Locations
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No Contacts or Locations Provided
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00000543     History of Changes
Other Study ID Numbers: 86
Study First Received: October 27, 1999
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Cardiovascular Diseases
Eclampsia
Heart Diseases
Hypertension
Pre-Eclampsia
Toxemia
Vascular Diseases
Hypertension, Pregnancy-Induced
Pregnancy Complications
Infection

ClinicalTrials.gov processed this record on August 19, 2014