J. Jap. Soc. for Mg Res. 2001  20 (1 and 2)

ARTICLE

The correlation between serum and cerebrospinal fluid magnesium levels. A study in infant with hydrocephalus

Kenji Hoshino, Kiyoshi Ogawa, Takashi Hishitani

Department of Pediatric Cardiology, Saitama Children's Medical Center

Object: The correlation between cerebrospinal fluid (CSF) magnesium level and brain damage is recently becoming recognized. In this study, we discussed the correlation between serum magnesium levels and CSF magnesium levels.
Methods: We examined magnesium levels in serum and CSF in pediatric patient with coarctation of aorta and hydrocephalus. Intravenous magnesium sulfate was given for hypomagnesemia. Serum total magnesium (StMg) level and cerebrospinal fluid total magnesium (CtMg) level were measured by enzyme assay. Serum ionized magnesium (SiMg) level and cerebrospinal fluid ionized magnesium (CiMg) level were measured using NOVA CRT8 (NOVA biomedical).
Results: The mean levels of StMg and CtMg were 1.93 mg/dl (range, 0.9-3.0 mg/dl) and 3.05 mg/dl (range, 2.7-3.4 mg/dl), and were not correlated (λ = 0.26). The mean levels of SiMg and CiMg were 1.26 mg/dl (range, 0.77-1.76 mg/dl) and 2.12 mg/dl (range, 1.78-2.35 mg/dl), and were not correlated (λ = 0.23). Although CSF magnesium levels were maintained within narrow limits, their changes resembled that of SiMg level. There was a positive correlation between CtMg level and CiMg level (λ =  0.69, P < 0.01), and the level of CSF percent ionized magnesium (CiMg/CtMg) was maintained within a narrow limits (52-61 %).
Conclusion: The CSF magnesium levels were maintained within a narrow limits and the extent of change was small. There were no significant correlations between serum magnesium levels and CSF magnesium levels. It was supposed that magnesium's CSF passage was depenent on SiMg level.

Key words: cerebrospinal fluid, magnesium, ionized magnesium, blood brain barrier

The probable role of inadequate maternal magnesium in low birth weight infants and the predisposition of such infants to early onset cardiovascular disease

Mildred S. Seelig, M.D.

M.P.H., Master of the American College of Nutrition Adjunct Professor, North Carolina University Medical Center, Chapel Hill

There is long accepted experimental, clinical, and epidemiologic evidence, that cardiovascular disease (CVD) is linked to magnesium(Mg) inadequacy, and that Mg has therapeutic value. Another disease in which low Mg levels and good response to parenteral Mg treatment have long been accepted is eclampsia, but poor Mg intake has rarely been considered as contributory. Data are accumulating that provide a direct link between the Mg findings in toxemia of pregnancy, and those in CVD. Clinical data show that poor maternal and fetal outcomes: spontaneous abortions, and low birth weight (LBW) are common with eclampsia; surveys have disclosed greater prevalence of unsuccessful pregnancies and of LBW infants with low maternal Mg intakes than with high. A series of epidemiologic studies implicate fetal malnutrition in programming for adult CVD, because ischemic heart disease and strokes occurred far more often in adults who had been of LBW than in those who had been normal in size at birth. Not explored in these studies was maternal Mg deficiency, which is a likely predisposing condition because: 1) eclamptic women have low Mg levels and their convulsions and hypertension are controlled by parenteral Mg; 2) Mg protects against thrombotic impairment of the placental circulation and thus of nutrient supply to the fetus, that is responsible for intrauterine growth retardation (IUGR), as well as for preterm birth; and 3) addition of high dose oral Mg to tocolytic drugs has been found the best protection against threatened premature delivery. Most fetal Mg is accumulated in the last trimester, so infants born before the normal Mg complement is reached are subject to infantile Mg deficiency, that increases risk of arterial damage, since Mg deficiency has been shown, in numerous studies of the young of many animal species, to cause cardiovascular lesions.

The influences of serum albumin levels on serum magnesium and zinc in elderly inpatients

O Noboru Saito, Naoto Tabata, Shinya Ootani, Hideo Nagatomo, Hiroki Kushihashi, Toshiaki Setoguchi, Saburou Saito, Ichirou Nakazima, Tasuku Murata, Kensuke Hori¹, Katuko Uchino²

Department of Internal Medicine and Adult Disease Research, ¹Dentist, ²Nutrition, Miyazaki Aiwa Hospital, Miyazaki

Purpose: Serum albumin is an appropriate index of protein nutrition. Elderly patients are often accompanied with hypoalbuminemia. Therefore, it was investigated how serum albumin levels influence on serum magnesium (Mg), zinc (Zn) and so on in elderly inpatients.
Method: In this study 378 inpatients (152 males, 226 females) were recruited, who were suffered from cerebral infarction, cerebral hemorrhage, ischemic heart disease, hypertension, diabetes mellitus or chronic renal failure, and were aged mean 80 years. They have ingested the prescribed diets of 1 200 to 1 600 kcal/day. They were divided into 12 groups according to the levels of serum albumin (Alb) and BUN, furthermore with or without magnesium oxide (MgO) administration. Concerning inpatients with below 30 mg/dl of BUN and without MgO, group Ia: less than 3.2 mg/dl of Alb, IIa: 3.3 to 3.7 mg/dl of Alb, IIIa: more than 3.8 mg/dl. About inpatients with MgO, Iam, IIam and IIIam were settled. In inpatients with more than 30 mg/dl of BUN and without MgO, Ib, IIb and IIIb were settled. In inpatients with MgO, Ibm, IIbm and IIIbm were also settled. Blood samples were obtained early in the morning for measuring serum biochemical parameters. Mg and Copper (Cu) were measured by colorimetry, and Zn was by atomic absorption method.

Results: Serum Mg levels were comparatively high when albumin levels increased in inpatients with below 30 mg/dl and without MgO (Table). By administration of MgO in doses of 1 to 3 g/day, serum Mg became higher (Table). Hemoglobin, serum total protein, Zn and iron (Fe) were higher when serum albumin increased, while serum potassium (K) and Cu did not change.

Table I. The changes of serum Mg levels in 12 groups.

mean, (): standard deviation, p < 0.01: IIa to IIIa, p < 0.005: Ia to IIIa, Ia to Iam, IIa to Iiam, IIIa to IIIam, Iam to Ibm

Conclusion: Serum Mg, Zn and Fe were comparatively higher when hemoglobin, serum albumin and total protein increased, that was when protein nutrition was improved.

Key words: ageing, Mg, Zn serum albumin

The relationships between dietary magnesium intake and magnesium intakes  of food groups, and nutrients intake among middle-aged women in Hokuriku area

Katsushi Yoshita¹, Masayuki Takahashi¹, Ritsuko Kimura², Kazuko Toda², Michiyo Kawahara², Akihiko Nakagawa², Etsuko Takase³, Yoko Kadoshima³, Masaji Tabata⁴, Katsuyuki Miura⁴, Muneko Nishijo⁴, Yuko Morikawa⁴, Hideaki Nakagawa⁴

¹ Department of Foods and Human Nutrition, Faculty of Human Life Sciences, Notre Dame Seishin University; ² Department of Nutrition, Kanazawa Medical University Hospital; ³ Department of Health Care, Kanazawa Medical University Hospital; ⁴ Department of Public Health, Kanazawa Medical University

A nutrition survey was conducted in 177 middle-aged Japanese women living in Hokuriku area aged 35 to 64 years based on dietary records, and total magnesium intake, nutrients intake, and magnesium intake by food groups were investigated.
The daily mean of magnesium intake was 229.9 mg the main sources of magnesium intake were pulses, cereals, fishes and shellfishes, green yellow vegetables and vegetables others. These foods intake were related strongly to total magnesium intake. The group with higher magnesium intake showed a higher intake of all nutrients. Magnesium intake showed positive correlation with all nutrients and energy. Percent of recommended dietary allowance (RDA) in Japan for magnesium intake was 21.7%. About 30 to 40 mg more magnesium intake per day would be necessary to accomplish the RDA through Japanese traditional dietary pattern which is rich fishes and shellfishes, pulses and vegetables.

Key words: magnesium, total magnesium intake, nutrients, food groups, recommended dietary allowances

Effect of calcium – Carbonate excess on some mineral metabolisms in young rats

Itsuhiko Koba, Tohru Matsui, Hideo Yano

Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University

The effects of excess calcium carbonate on mineral metabolism were studied in young rats. Fifteen 3-weeks-old rats were given one of 3 diets (1C: containing 5 g/kg calcium as calcium carbonate, 5C: containing 25 g/kg calcium as calcium carbonate, and GC: containing 25 g/kg calcium as calcium carbonate and calcium gluconate). After 10 weeks, mineral concentrations (calcium (Ca), magnesium (Mg), phosphorus (P), zinc (Zn), copper (Cu) and iron (Fe)) in various tissues were measured. Weight gain was significantly lower in 5C group than 1C group but weight gain in GC group did not significantly differ from those in the other groups. The rats given either high-Ca diet showed significantly lower feed efficiency than those fed on 1C diet. Plasma and femoral Mg concentrations were significantly lower in the 5C and GC groups than in 1C group. Although GC group showed similar plasma Mg level to 5C group, femoral Mg was significantly higher in GC group than in 5C group. Femoral P level was significantly lower in 5C group than in 1C group, but GC group did not showed the significant difference from the other groups. Both high-Ca diets significantly decreased renal Cu and Zn concentrations and plasma Cu but these diets increased hepatic Cu and Zn concentrations and femoral Zn. These results show that calcium excess depresses Mg, P and Fe availabilities and affects distributions of Mg, Zn and Cu, irrespective of Ca source. The partial substitution of carbonate to gluconate is likely to improve Mg availability.

Key words: calcium excess, calcium source, tissue mineral, rat