Oral Calcium in Pregnant Women With Hypertension
Study Details
Study Description
Brief Summary
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 or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Phase 2 |
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.
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
Outcome Measures
Primary Outcome Measures
Eligibility Criteria
Criteria
Pregnant women with chronic hypertension.
Contacts and Locations
Locations
No locations specified.Sponsors and Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
- Curnow KM, Pham T, August P. The L10F mutation of angiotensinogen is rare in pre-eclampsia. J Hypertens. 2000 Feb;18(2):173-8.
- Hojo M, August P. Calcium metabolism in normal and hypertensive pregnancy. Semin Nephrol. 1995 Nov;15(6):504-11. Review.
- 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.
- 86
- R01HL048846