Uri Eylath

The effects of chromium supplementation on serum glucose and lipids in patients with and without non-insulin-dependent diabetes

Seventy-six patients with established atherosclerotic disease were treated daily with either 250 micrograms of chromium orally as chromium chloride or a placebo for a period of 7 to 16 months (mean, 11.1 months). Serum chromium increased from 2.69 +/- 0.09 to 12.12 +/- 0.77 nmol/L (mean +/- SE, P less than .005). Serum triglycerides were lower (1.68 +/- 0.11 and 2.10 +/- 0.14 nmol/L, respectively; P less than .02) in the chromium-treated patients than in the patients who received placebo, and serum high-density lipoprotein (HDL) increased (from 0.94 +/- 0.05 to 1.14 +/- 0.07 mmol/L, P less than .005) in the patients who received chromium. There was no change in serum cholesterol or blood glucose during the study.

Serum, lymphocyte, and erythrocyte potassium, magnesium, and calcium concentrations and their relation to tachyarrhythmias in patients with acute myocardial infarction

Serum, lymphocyte, and erythrocyte potassium, magnesium, and calcium levels were measured in 215 patients during the five days following acute myocardial infarction. Serum potassium fell from 4.25 +/- 0.05 to 4.08 +/- 0.06 mmol/liter (p less than 0.001), magnesium from 0.93 +/- 0.01 to 0.85 +/- 0.01 mmol/liter (p less than 0.001), and calcium from 2.4 +/- 0.02 to 2.2 +/- 0.08 mmol/liter (p less than 0.001). Lymphocyte potassium increased from 18.1 +/- 1.5 to 51.6 +/- 4.3 pmol/100 cells (p less than 0.001) and magnesium from 2.0 +/- 0.1 to 8.2 +/- 0.8 pmol/100 cells (p less than 0.001), whereas calcium decreased from 2.9 +/- 0.27 to 1.4 +/- 0.25 pmol/100 cells (p less than 0.001). Erythrocyte cations remained constant. There was a larger increase in lymphocyte potassium in patients with tachyarrhythmias than in patients without (70.4 and 46.9 pmol/100 cells, respectively, p less than 0.001), whereas the presence of a high lymphocyte magnesium level was associated with a significant decrease in the development of tachyarrhythmias, despite high potassium concentrations. It is suggested that lymphocyte cation concentrations mirror myocardial interstitial concentrations and that a high interstitial magnesium level has a protective effect on the increased cell excitability due to, and despite, a high interstitial potassium level.

Chromium and Cholesterol-Induced Atherosclerosis in Rabbits

Thirty-three rabbits on a cholesterol-enriched diet were randomized into 6 groups and treated with daily injections of either water, 20 micrograms of potassium chromate or 1, 5, 10 or 20 micrograms of chromium chloride, respectively, for 135 days with a 2- to 10-fold increase in serum chromium. There was a marked reduction in the percentage of aortic intimal surface covered by plaque, in aortic weight and cholesterol content in the treated animals. Rabbits treated with 20 micrograms of chromium chloride showed a better response than those treated with either 10 or 20 micrograms of potassium chromate.

Correlation between manifestations of digoxin toxicity and serum digoxin, calcium, potassium, and magnesium concentrations and arterial pH.

In 18 patients with gastrointestinal manifestations of digoxin toxicity the mean serum digoxin concentration (+/- SEM) was 3.16 micrograms/l (+/- 0.25), the calcium to potassium ratio 0.31 (+/- 0.01), and the mean arterial pH 7.406 (+/- 0.017). In contrast 19 patients with digoxin induced automaticity had a mean serum digoxin concentration of 1.24 micrograms/l (+/- 0.15; p less than 0.001), a calcium to potassium ratio of 0.38 (+/- 0.01; p less than 0.01), and an arterial pH of 7.498 (+/- 0.008; p less than 0.001). Eight out of 13 patients with digoxin induced cardiotoxicity had serum concentrations of the drug within the therapeutic range (0.8-2.0 micrograms/l). The calcium to potassium ratio, however, was lower than in the patients with automaticity (0.31 +/- 0.02; p less than 0.01) and the arterial pH was 7.370 (+/- 0.033; p less than 0.05). Serum magnesium concentrations were similar in all groups. In this study patients with digoxin induced gastrointestinal symptoms had high serum concentrations of the drug, whereas those with drug induced automaticity had therapeutic concentrations. This second group, however, was identified by their higher calcium to potassium ratios and higher pH values.

Serum magnesium levels in acute medical and surgical conditions

Abstract Serum magnesium was measured in a series of acute medical and surgical patients and before and during childbirth. In all cases there was a significant fall in serum magnesium only if there was associated pain whereas in acute medical patients without pain and patients undergoing elective surgery there was no change.

Influence of Chronic Diuretic Therapy on Serum, Lymphocyte and Erythrocyte Potassium, Magnesium and Calcium Concentrations

Serum, lymphocyte and erythrocyte potassium, magnesium and calcium concentrations were measured in 31 patients with congestive cardiac failure and 14 patients with mild noncomplicated hypertension, who had been receiving either furosemide or chlorothiazide (with or without potassium supplementation) or a combination of hydrochlorothiazide and amiloride for more than 6 months. Lymphocyte potassium concentrations (pmol/100 cells +/- SE) were as follows: controls 18.1 +/- 1.5, furosemide 14.1 +/- 0.9 (p less than 0.001), furosemide + potassium 12.3 +/- 0.7 (p less than 0.001), chlorothiazide 13.1 +/- 1.0 (p less than 0.001) and hydrochlorothiazide + amiloride 18.6 +/- 0.7 (p = NS). There was a statistically significant relationship between the number of months the patients had been on diuretics and their lymphocyte potassium concentrations. Serum electrolytes, apart from the group receiving chlorothiazide who showed a significant fall in serum K, were unchanged.

Lymphocyte Potassium and Magnesium Concentrations as Prognostic Factors after Acute Myocardial Infarction

215 patients admitted with acute myocardial infarction were prospectively evaluated for prognostic factors. When lymphocyte potassium concentration increased by up to twofold of normal, a high lymphocyte magnesium concentration was associated with a good prognosis. However, when the increase in lymphocyte potassium concentration was greater than twofold, the presence of a high lymphocyte magnesium made no difference to mortality. Age, the female sex, anterior wall infarction, high serum enzymes, heart failure, diabetes mellitus in females and serious arrhythmias were all bad prognostic signs.

Effects of hydrochlorothiazide, diltiazem and enalapril on mononuclear cell sodium and magnesium levels in systemic hypertension☆

Sixteen patients (mean age 68 years) with mild to moderate hypertension were treated with either diltiazem or hydrochlorothiazide for 6 weeks, followed by enalapril for a further 6 weeks. A second group of 40 patients (mean age 71 years) was treated with either hydrochlorothiazide or enalapril for 12 weeks; nonresponders received both drugs for 8 weeks. Treatment with hydrochlorothiazide or enalapril resulted in a lowering of systolic and diastolic blood pressures, but diastolic pressure was lower in patients treated with enalapril (89 +/- 2 and 82 +/- 2 mm Hg, respectively; p less than 0.05). Treatment with diltiazem resulted in a decrease in diastolic pressure only. Treatment with hydrochlorothiazide resulted in a 17% decrease in serum potassium (p less than 0.05), which returned to normal when enalapril was substituted. Hydrochlorothiazide also produced a 23% decrease in mononuclear cell sodium content at 4 weeks (p less than 0.01), with a further 15% decrease at 12 weeks (p less than 0.05). Mononuclear cell potassium and magnesium also decreased at 12 weeks by 18 and 16%, respectively (p less than 0.05). All these effects were reversed when enalapril was substituted. A similar pattern of events was seen with diltiazem, which was again reversed with enalapril. Finally, there was no relation between changes in mononuclear cell sodium or other cation content and changes in blood pressure.

A routine method for the measurement of the sodium, potassium, magnesium and calcium content of human lymphocytes

We describe a rapid, single-step procedure for the isolation of human lymphocytes from whole blood, suitable for a routine clinical laboratory. Lymphocyte content of sodium, potassium, magnesium and calcium were measured simultaneously in a group of controls and found to fall within expected ranges. Expression of results per mg protein produced less inter-individual variation than per unit cell. In order to examine another, physiologically different but normal population, women during pregnancy were also studied. The cation content of lymphocytes expressed per mg protein was significantly lower than for controls due to a 44% increase in protein content per cell.

Effects of Enalapril on Lymphocyte Sodium, Potassium, Magnesium and Calcium Levels in Patients with Severe Congestive Heart Failure

Fifteen patients (median age 73 years) with severe congestive heart failure were treated with Enalapril for a total of 12 weeks with a significant improvement in their right atrial pressures and in their functional state. Renal function, serum potassium, magnesium and calcium levels were unchanged. Lymphocyte sodium, potassium and calcium levels were generally lower than control values throughout the study but these differences were only statistically significant early in the study. Lymphocyte magnesium levels were unchanged. These findings are in contrast to those previously reported in the literature for such patients treated with conventional diuretics.