1Renal Division, Hippocration Hospital, Thessaloniki
2B Inside Drugs Division, Hippocration Hospital, Thessaloniki
2B Inside Drugs Division, Hippocration Hospital, Thessaloniki
Summary
Introduction
Magnesium is the second in abundance intracellular ion. The connection between magnesium and cardiovascular system, arterial hypertension, central nervous system, skeletal muscle groups and being pregnant, is an already established data.
The principle a part of complete physique magnesium is concentrated within the bones, only one% is within the serum whereas the 31% is within the intracellular area diluted within the cytoplasm or conjuncted to enzymes or ATP.
The same old every day magnesium consumption is 200-300 mg however only one/3 of this amount is absorbed by means of small gut. The magnesium renal excretion fee is roughly 100 mg per day. Regular values of serum magnesium are thought of these between 0.75 and 1.5 mmol/L. Values beneath the edge of 0.75 mmol/L are outlined as hypomagnesemia.
Extensive number of strategies have been used to measure magnesium in serum and intracellular area however none was dependable. Throughout final a long time by the use of new methods, the exact willpower of magnesium focus turned attainable. Magnesium depletion happens when intracellular magnesium shops are depleted. Since there isn’t a chance to find out the degrees of intracellular magnesium the doctor is obliged to estimate the magnesium shops utilizing the values of serum magnesium.
The principle downside in prognosis of intracellular magnesium depletion is that it may coexist even with regular serum values. This case was confirmed with muscle biopsy in sufferers with regular serum magnesium values and proof of magnesium shops depletion. Nevertheless, nearly all of sufferers with decreased complete magnesium have low serum Mg as effectively. Thus, in medical observe, sufferers with hypomagnesemia are thought of as having intracellular magnesium depletion. The measurement of serum Mg is straightforward and thought of as the principle methodology of estimation the Mg shops. An different methodology for intracellular Mg estimation is measurement of Mg focus in purple blood cells or in monocytes or the 24 hour Mg renal excretion. Roughly 1/3 of serum Mg is in conjuction with albumin and through hypoalbuminemia false decreased values of Mg are encountered. Moreover though the serum Mg degree is regular there could possibly be intracellular depletion of Mg that may trigger signs. Sadly there isn’t a fast and direct methodology of measuring the whole Mg ranges in the mean time.
Probably the most dependable methodology in prognosis of Mg intracellular depletion is by measuring the Mg excretion by means of renal system following Mg loading. This methodology is indicated in sufferers exhibiting signs of hypomagnesemia from the cardiovascular and nervous techniques whereas having regular serum values. Step one is the measurement of every day Mg excretion in 24hour urine assortment. Whether it is low (for instance 1.1.mmol/d), sulphur magnesium is run intravenously (0.1mmol/kg of physique weight). Sufferers with intracellular Mg depletion excrete lower than 50% of the administered drug, whereas sufferers with regular values excrete greater than 60%. The process is recomended with warning in sufferers with renal insufficiency. Intravenous Mg administration is effectively tolerated whereas per os administration causes unwanted side effects similar to diarrhoea. The issue has been overcome through the use of magnesium chloride in skinny capsules. The principle indication for administering magnesium remedy is the presence of predisposing components for hypomagnesemia.
Causes of hypomagnesemia
Hypomagnesemia as a aspect impact of diuretics is the most typical explanation for this disturbance. Loop diuretics and thiazides are concerned in elevated Mg excretion. An different widespread explanation for hypomagnesemia is the decreased Mg consumption within the aged and sufferers with disturbances within the intestinal absorption. Within the creating international locations Mg consumption is insufficient. Greens and fish are thought of wealthy in Mg, whereas consumption of fatty meals, salt, vitamin D, proteins and calcium will increase the necessity for Mg. Sufferers with acute or continual use of alcohol have Mg depletion as a result of osmotic diuresis by the alcohol. The identical mechanism have to be implicated within the growth of Mg depletion within the diabetic sufferers.
Indicators of Mg depletion
The principle indicators of Mg depletion concern neuromuscular and central nervous system, in addition to electrolyte disturbances (Desk 1).
Pathophysiology – “magnesium bradycardia”
Cardiovascular manifastations of Mg depletion
Hypomagnesemia in congestive coronary heart failure(CHF)
In experimental fashions with out natural cardiac illness hypomagnesemia brought on indicators of cardiac failure which was improved after Mg administration8, 9.
The principle causes of hypomagnesemia in CHF embody: administration of medicine similar to furosemide, thiazides, digoxin, in addition to activation of renin-aldosterone system or the arginine-vasopressin system and oedema of intestinal villi10. Though the prevalence of hypomagnesemia is dependent upon dietary Mg consumption in addition to the usual values of every laboratory, it’s estimated that it’s about 7% amongst sufferers in coronary unit and 37% in sufferers utilizing diuretics.