Magnesium supplementation to prevent high blood pressure in pregnancy: a randomised placebo control trial.

PURPOSE: To assess if hypertension during the last part of pregnancy could be prevented by magnesium supplementation. METHODS: Pregnant primagravida women from a local antenatal care unit were given an oral supply of 300 mg magnesium as citrate or placebo from pregnancy week 25 in a randomised double-blind setup. Blood pressure was recorded during pregnancy as well as pregnancy outcome. RESULTS: In the magnesium-supplemented group, the average diastolic blood pressure at week 37 was significantly lower than in the placebo group (72/1.4 mean/SEM vs 77/1.4, p = 0.031). The number of women with an increase in diastolic blood pressure of ≥15 mmHg was significantly lower in the magnesium group compared with the women who received placebo (p = 0.011). There was an inverse relation between the urinary excretion of magnesium during pregnancy and the diastolic blood pressure (p = 0.005). CONCLUSIONS: Magnesium supplementation prevented an increase in diastolic blood pressure during the last weeks of pregnancy. The relation between diastolic blood pressure and urinary excretion of magnesium suggests that magnesium is involved in the regulation of blood pressure and that the increase in diastolic blood pressure in pregnancy could be due to a lack of magnesium.

Magnesium Supplementation and Blood Pressure in Pregnancy: A Double-Blind Randomized Multicenter Study.

OBJECTIVE: To investigate the effect of magnesium (Mg) supplementation in healthy pregnant women for prevention of blood pressure increase. Secondary outcomes were comparison of biomarkers for hypertensive disorders and labour and fetal outcomes between the groups. METHODS: Two hundred nulliparous healthy pregnant women were double-blind randomized to receive Mg daily or placebo. RESULTS: There were no differences in blood pressure increase. However, among the Mg-treated women, there was a significant negative correlation between increase in blood levels of magnesium and increase in systolic blood pressure (p = 0.042). Magnesium supplementation seems to be safe for both mother and infant. CONCLUSION: Magnesium supplementation in healthy first-time pregnant women is not to be recommended for prevention of blood pressure increase. Supplementation in risk pregnancies needs to be further investigated. The study is listed on the ISRCTN registry with study ID 13890849.

A study of different fabrics to increase radar cross section of humans.

This purpose of the study was to increase the visibility on radar for unprotected pedestrians with the aid of conducting fabric. The experiment comprised measurements of four types of fabric to determine the radio frequency properties, such as radar cross section (RCS) for the vehicle radar frequency 77 GHz and transmission (shielding) in the frequency range 3-18 GHz. Two different thicknesses of polypyrrole (PPy) nonvowen fabric were tested and one thickness for 30 % and 40 % stainless steel fabrics respectively. A jacket with the thinner nonvowen material and one with 40 % steel were tested and compared to an unmodified jacket in the RCS measurement. The measurement showed an increase in RCS of 4 dB for the jacket with the 40 % steel lining compared to the unmodified jacket. The transmission measurement was aimed at determining the fabric with the highest transmission of an incoming radio wave. The 30 % steel fabric and the two thicknesses of the nonvowen fabrics were tested. One practical application is for example the use of radar reflective material in search and rescue (SAR) clothes. The study showed that the 30 % steel fabric was the best candidate for further RCS measurements.

Blood pressure in pregnancy and magnesium sensitive genes.

OBJECTIVES: High blood pressure during the last part of pregnancy is a risk indicator of pre-eclampsia and eclampsia which augment infant and maternal morbidity and mortality. Magnesium deficiency has been related to the risk of hypertension. A study was performed to assess the relation between pregnancy induced hypertension, excretion of urinary magnesium and expression of magnesium sensitive genes (MgSG). METHODS: A cohort of healthy, nulliparous women with singleton pregnancies was recruited. Blood pressure was recorded throughout pregnancy. Urinary magnesium excretion and expression of MgSGs in leukocytes were determined. RESULTS: The expression of the gene TRPM6 was higher among pregnant women compared to non-pregnant controls at week 12. All other genes had lower expressions in pregnant women. At week 37 the expressions of all genes were lower than at week 12. The expressions of SLC41A1, SLC41A3, and TRPM7 were related to the systolic and diastolic blood pressures. Furthermore, the expression of TRPM6 was related to the urinary excretion of magnesium and the change in diastolic blood pressure weeks 12-37 was inversely related to the change in magnesium excretion. CONCLUSIONS: Systolic and diastolic blood pressure and the excretion of magnesium during pregnancy were related to the expression of different MgSGs. The results suggest that magnesium is involved in the regulation of blood pressure during pregnancy.