Relationship between calcium intake, serum ionized calcium and elevated blood pressure in primigravida after 24 weeks of Gestation

Abstract

Data from the 1992 National Household Survey revealed that Matemal Mortality Rate (MMR) in Indonesia was still high, 425 per 100,000 live births. One of the major cause of this high MMR is Eclampsia. Research has shown an inversed relationship betvveen calcium (Ca) intake and the incidence of Preeclampsia. Preeclampsia it self can be followed by Eclampsia. This study involving 86 primigravidas observedfrom 24 weeks to 36 weeks of gestation. The result showed Ca intake on 24th, 32nd and 36thweeks of gestation were 63 Vo, 67 Vo and 63 Vo of the Recommended Dietary Allowances (RDA) respectively. Serum ionized Ca bn 24th and 36th weeks of gestation were L06 and 1.05 mmol/L The incidence of Preeclampsia was 8,1 Vo, I diagnosed at 32 weeks of gestation and the other at 36 weeks of gestation. Statistical analysis showed no significant relationship between Ca intake, serum ionized Ca and the incidence of P re eklamp sia (p> 0.0 5 ). Keyw ords : calcium, preeclampsia, primipravida INTRODUCTION It was noted that Indonesia had the highest Maternal Mortality Rate (MMR) among the Asean Countries. Data from The 1992 National Household Survey showed that MMR decreased from 450 per 100,000 live births to 425 per 100,000 live births in 1992. One of the major cause of this high MMR is Eclampsia. It was revealed that Preeclampsia, a Pregnancy-induced hypertension with proteinuria and or edema could be a serious complication to Eclampsia.l From several studies in Indonesia, the incidence of Preeclampsia * Department of Nutrition, Facuby of Medicine, Trisakti University, J akarta, Indonesia ** Department of Nutrition, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia *** Department of Obstetics and Gynaecology, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia was known to be betwee n 4 to l7 .5Eo.''3'4's Pr.gnuny represent a very special and demanding period for calciurn (Ca) needs and requirements. Furthermore, pregnancy is a period of high Ca demands due to fetal requirements. At the end of pregnancy, fetal Ca accumulation totals approximately 30 grams. The transport of ionized Ca from the mother to the fetus increases from about 50 grams per 24 hours at 20 weeks of gestation to a maximum of about 330 grams per 24hours at 35 weeks of gestation.6 Epidemiologic investi gations, I aboratory ev aluations and clinic al trials all confirmed that the relationship between Ca and blood pressure extends to include the pregnant state. On the basis of current information it was clear the Ca supplementation during pregnancy lowers blood pressure. Additionally the effect of Ca on blood pressure may influence the incidence of preeclampsia.T Although the mechanism for these effects has not been entirely elucidated, Ca supplementation appears to afVol 6, No 4, October December 1997 fect circulating concentration of parathyroid hormone and renin, which may modulated intracellular ionized Ca, resulting in its observed effect on smooth-muscle relaxation.o The purpose of this study was to deter_ mine the relationship between Ca intake, serum ionized Ca and the incidence of preeclampsia in primigravida after 24 weeks of gestation. METHODS The design of this study is a cross sectional, followed by follow-up study ftom 24 weeks to 36 weeks of gestation involving 110 pregnant women. Fourty eight women were out patients of Department of Obstetrics and Gyn e, University of Indonesi Cipto Mangun_ kusumo from Maternity Hospital in Jakarta. The study was conducted from March 1996 until August 1996. The inclusion criteria for subjects of this study were primigravida without any serious illness, none of sub_ jects had a history of hypertension, cardiac and gastrointestinal tract diseases, blood pressure within a normal limits, no edema, normal blood urea and and negative urine protein. tt, ere interviewed to identify th of and level of income. Body od pressure, dietary evaluation using 2 days recall method for calorie, protein and Ca intakes and blood examina_ tion for serum ionized Ca were also measured. Follow up study consisted of three observations, on 28th,32nd and 36th weeks of gestation. On 2gth weeks o 3 b d Ca. was determined using ,'Kertu Men il. Statistic analysis ddne using chi s RESULT Eleven of the 48 subjects from RSUpNCM and l3 of tbe 62 subjects from RSBBK were excluded from this (Table l). Calcium and Blood pressure in pimigravida Zl7 Table l. Characteristic of subjects Characteristic Sum (n=86) Age Education Low Middle High Activity Work Not work Income Low Middle Nutritional status Under Good 39 38 9