cardiovascular-agents and Magnesium-Deficiency

There are many reasons to expect magnesium deficiency in patients with chronic congestive heart failure. Medical therapy, neurohormonal activation and decreased dietary intake could all contribute to low concentrations of serum and muscle magnesium. Although the ideal serum level of this electrolyte is not known, multiple studies have documented lower magnesium concentrations in patients with heart failure than in normal persons. Magnesium deficiency could theoretically produce hemodynamic deterioration and ventricular arrhythmias. These complications have been observed in animals and in patients without heart failure, and magnesium repletion has reversed the adverse effects of hypomagnesemia in some patients. However, the consequences of chronic depletion of the electrolyte have not been adequately evaluated. Because of the high incidence of sudden death in patients with severe congestive heart failure, well designed investigations to determine the importance of magnesium are needed.

Topics: Arrhythmias, Cardiac; Cardiovascular Agents; Heart Ventricles; Hemodynamics; Humans; Magnesium; Magnesium Deficiency

Dietary magnesium (Mg) deficiency is more prevalent than generally suspected and can cause cardiovascular lesions leading to disease at all stages of life. The average American diet is deficient in Mg, especially in the young, in alcoholic persons, and in those under stress or with diseases or receiving certain drug therapies, who have increased Mg needs. Otherwise normal, Mg-deficient diets cause arterial and myocardial lesions in all animals studied, and diets that are atherogenic, thrombogenic and cardiovasopathic, as well as Mg-deficient, intensify the cardiovascular lesions, whereas Mg supplementation prevents them. Diuretics and digitalis can intensify an underlying Mg deficiency, leading to cardiac arrhythmias that are refractory unless Mg is added to the regimen. Potassium (K) depletion in diuretic-treated hypertensive patients has been linked to an increased incidence of ventricular ectopy and sudden death. K supplementation alone is not the answer. Mg has been found to be necessary to intracellular K repletion in these patients. Because patients with congestive heart failure and others receiving diuretic therapy are also prone to chloride loss leading to metabolic alkalosis that also interferes with K repletion, the addition of Mg and chloride supplements in addition to the K seems prudent.

Topics: Cardiovascular Agents; Cardiovascular Diseases; Chlorides; Diet; Female; Heart Diseases; Humans; Hypertension; Magnesium; Magnesium Deficiency; Potassium; Pregnancy; Stress, Physiological

Hypomagnesemia has been associated with diabetes, cardiovascular disease, and other disorders. Drug use has been suggested as one of the risk factors for low magnesium (Mg) levels. In the elderly population, prone to polypharmacy and inadequate Mg intake, hypomagnesemia might be relevant. Therefore, we aimed to investigate associations between drug use and plasma Mg.. Cross-sectional data of 343 Dutch geriatric outpatients were analysed by Cox and linear regression, while adjusting for covariates. Drug groups were coded according to the Anatomical Therapeutic Chemical classification system; use was compared to non-use. Hypomagnesemia was defined as plasma Mg < 0.75 mmol/l and <0.70 mmol/l.. Prevalence of hypomagnesemia was 22.2% (Mg < 0.75 mmol/l) or 12.2% (Mg < 0.70 mmol/l); 67.6% of the patients used ≥5 medications (polypharmacy). The number of different drugs used was inversely linearly associated with Mg level (beta -0.01; p < 0.01). Fully adjusted Cox regression showed significant associations of polypharmacy with hypomagnesemia (Mg < 0.75 mmol/l) (prevalence ratio (PR) 1.81; 95%CI 1.08-3.14), proton pump inhibitors (PR 1.80; 95%CI 1.20-2.72), and metformin (PR 2.34; 95%CI 1.56-3.50). Moreover, stratified analyses pointed towards associations with calcium supplements (PR 2.26; 95%CI 1.20-4.26), insulins (PR 3.88; 95%CI 2.19-6.86), vitamin K antagonists (PR 2.01; 95%CI 1.05-3.85), statins (PR 2.44; 95%CI 1.31-4.56), and bisphosphonates (PR 2.97; 95%CI 1.65-5.36) in patients <80 years; selective beta blockers (PR 2.01; 95%CI 1.19-3.40) if BMI <27.0 kg/m. As polypharmacy and several medications are associated with hypomagnesemia, Mg merits more attention, particularly in diabetes, cardiovascular disease, and in side-effects of proton pump inhibitors and calcium supplements.

Topics: Aged; Aged, 80 and over; Ambulatory Care; Cardiovascular Agents; Cross-Sectional Studies; Drug Interactions; Drug-Related Side Effects and Adverse Reactions; Female; Humans; Hypoglycemic Agents; Magnesium; Magnesium Deficiency; Male; Polypharmacy; Prevalence; Risk Factors

Topics: Cardiovascular Agents; Heart Failure; Humans; Magnesium; Magnesium Deficiency

It has been demonstrated that audiogenic stress (AS) can induce elevation of arterial blood pressure (ABP) in animals and humans and that noise-induced hearing loss may be associated with alterations in Mg metabolism. Experiments were designed to determine whether 1) there is a causal relationship among environmental noise stress, serum and vascular tissue (aortas and portal veins) Mg contents, and development of hypertension and 2) such noise-induced hypertension has a microcirculatory basis and what the mechanism may be. Rats maintained on normal Mg-containing diets for 12 wk (plasma [Mg] = 0.96 +/- 0.02 mM) and subjected to AS (85 dB(A), 12 h/day for 8 wk; 95 dB(A), 16 h/day for 4 wk) demonstrated significant elevation in systolic and diastolic ABP; plasma [Mg] showed a 15% deficit, whereas aortic and portal vein muscle exhibited slight reductions in Mg content and elevation in Ca. Moderate and more severely Mg-deficient animals not subjected to AS also exhibited significant elevations in systolic and diastolic ABP; vascular tissue Mg content decreased, whereas Ca content rose. Animals subjected to combined Mg deficiency and AS for 12 wk exhibited the greatest deficits in plasma and vascular muscle Mg and the greatest elevations in systolic and diastolic ABP; vascular tissue Ca contents also showed the greatest increases. In situ measurements of mesenteric arterioles, venules, and precapillary sphincters in the various subgroups revealed that the lower the plasma [Mg], the more constricted the microvessels, and the higher the ABP, the lower the plasma [Mg]. Capillary blood flow velocities were decreased in relation to the degree of plasma Mg deficit.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Calcium; Cardiovascular Agents; Diet; Hypertension; Magnesium; Magnesium Deficiency; Male; Microcirculation; Muscle, Smooth, Vascular; Noise; Rats; Rats, Inbred Strains; Stress, Physiological