Elevated late-night salivary cortisol levels in elderly male type 2 diabetic veterans.

Objective: Late-night salivary cortisol (LNSC) is reportedly highly accurate for the diagnosis of Cushing's syndrome (CS). However, diagnostic thresholds for abnormal results are based on healthy, young populations and limited data are available on its use in elderly populations with chronic medical conditions. The purpose of this study was to evaluate LNSC levels in elderly male veterans with and without diabetes.

Effect of experimental human magnesium depletion on parathyroid hormone secretion and 1,25-dihydroxyvitamin D metabolism.

Magnesium (Mg) deficiency in man may result in hypocalcemia, impaired PTH secretion, and low serum concentrations of 1,25-dihydroxyvitamin D [1,25-(OH)2D]. To determine whether these changes are due to selective Mg depletion, we studied 26 normal subjects before and after a 3-week low Mg (less than 1 meq/day) diet. This diet induced Mg deficiency, as demonstrated by a fall in pre- to postdiet serum Mg levels from 0.

Treatment of hypercalcemia of malignancy with intravenous etidronate. A controlled, multicenter study. The Hypercalcemia Study Group.

In a prospective, randomized, double-blind, multicenter study, 202 patients with cancer from 19 medical centers were treated for hypercalcemia of malignancy with daily intravenous infusions of etidronate disodium (136 patients) or saline alone (66 patients) for 3 consecutive days. Patients also received up to 3.25 L of saline daily during the treatment period.

Effect of intravenous epinephrine on serum magnesium and free intracellular red blood cell magnesium concentrations measured by nuclear magnetic resonance.

Hypomagnesemia is a common clinical finding in hospitalized patients and can cause hypocalcemia, cardiac arrhythmias, muscular weakness, and hypokalemia. Hypomagnesemia usually implies cellular magnesium (Mg) depletion, but stress and some clinical conditions which raise serum catecholamine concentrations may lower serum Mg (sMg) concentrations. To help investigate the mechanism and degree of the effect of catecholamines on sMg concentration, we gave intravenous epinephrine (0.

Low intracellular magnesium in patients with acute pancreatitis and hypocalcemia.

To determine the role of magnesium deficiency in the pathogenesis of hypocalcemia in acute pancreatitis, we measured magnesium levels in serum and in peripheral blood mononuclear cells in 29 patients with acute pancreatitis, 14 of whom had hypocalcemia and 15 of whom had normal calcium levels. Only six patients had overt hypomagnesemia (serum magnesium less than 0.70 mmol per liter [1.

Prospective evaluation of parenteral magnesium sulfate in the treatment of patients with reentrant AV supraventricular tachycardia.

This study prospectively assessed the electrophysiologic effects of parenteral magnesium sulfate administration on paroxysmal atrioventricular (AV) reentrant supraventricular tachycardia and the efficacy of magnesium to terminate these arrhythmias. Eleven normomagnesemic patients, seven with orthodromic reentrant supraventricular tachycardia that used an accessory AV pathway, and four with typical AV nodal reentry were examined. All patients had a history of sustained supraventricular tachycardia requiring pharmacologic therapy or electrical cardioversion for termination of tachycardia.

Determination of intracellular free magnesium by nuclear magnetic resonance in human magnesium deficiency.

Magnesium (Mg) deficiency is a common clinical problem. As Mg is predominantly an intracellular cation and Mg deficiency may exist despite normal serum Mg (sMg) concentrations, we have utilized nuclear magnetic resonance (NMR) techniques in an attempt to measure intracellular free Mg (Mg2+) in red blood cells (RBC). Twenty normal subjects, 22 hypomagnesemic patients, and 17 normomagnesemic alcoholic patients were studied.

Magnesium homeostasis in critically ill patients.

Magnesium (Mg) deficiency is a common finding in critically ill patients. Mg deficiency results primarily from gastrointestinal or urinary Mg losses, but malnutrition and decreased dietary Mg intake may hasten the development of Mg depletion. In our medical intensive-care unit, we have found hypomagnesemia in 65% of patients with normal serum creatinine concentrations.

Mechanisms of blood pressure regulation by magnesium in man.

In order to determine the effect and mechanism of Mg on vascular tone, a 3-hour infusion of Mg (200 mg/h) was administered to normal subjects. The Mg infusion resulted in a drop in blood pressure (BP), a rise in renal blood flow, and an increase in urinary 6-keto-PGF1 alpha excretion. Cyclooxygenase inhibition with indomethacin and the calcium channel blocker, nifedipine, prevented these vascular effects of Mg.

Electrophysiologic effects of intravenous magnesium in patients with normal conduction systems and no clinical evidence of significant cardiac disease.

Parenteral magnesium has been used for several decades in the empiric treatment of various arrhythmias, but the data on its electrophysiologic effects in man are limited. We evaluated the electrophysiologic effects of magnesium sulfate (MgSO4) administration in eight normomagnesemic patients with normal mononuclear cell magnesium content, who had no clinically significant heart disease and had normal baseline electrophysiologic properties. After administration of intravenous MgSO4, serum magnesium rose significantly from 1.

Hypercalcemia and abnormal 1,25-dihydroxyvitamin D concentrations in leprosy.

Two patients with lepromatous leprosy and hypercalcemia are presented. Serum immunoreactive parathyroid hormone and urinary cyclic adenosine monophosphate concentrations were suppressed. Serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] concentrations were elevated in one patient and normal in the other.

Low blood mononuclear cell magnesium content and hypocalcemia in normomagnesemic patients.

Hypomagnesemia can cause hypocalcemia. Because less than 1% of the total body magnesium (Mg) is in extracellular fluids, however, patients may be Mg-deficient despite normal serum Mg concentrations. To determine if hypocalcemia can be seen in patients who have normal serum Mg concentrations but low intracellular Mg, we studied the serum and mononuclear cell Mg contents in 82 alcoholic subjects, 30 of whom had hypocalcemia that could not be explained by other known causes of hypocalcemia.

Blood mononuclear cell magnesium in normal pregnancy and preeclampsia.

Magnesium (Mg) is effective in the treatment of pregnancy-induced hypertension (PIH). In order to determine if patients with PIH are Mg deficient, we assessed mononuclear cell magnesium content (mMg) and serum Mg concentrations (sMg) in 23 normal pregnant women and in 12 women with PIH admitted in active labor. The sMg concentration in women with PIH was 1.

Assessment of the free fraction of 25-hydroxyvitamin D in serum and its regulation by albumin and the vitamin D-binding protein.

We measured the free fraction of 25-hydroxyvitamin D (25OHD) in human serum and determined that 25OHD bound to a component with an affinity constant of 7 X 10(8) M-1 and a concentration of 4.5 X 10(-6) M. This concentration was equal to that of the vitamin D-binding protein (DBP) in the same serum sample.

Free 25-hydroxyvitamin D levels are normal in subjects with liver disease and reduced total 25-hydroxyvitamin D levels.

We determined the free fraction of 25-dihydroxyvitamin D (25OHD) in the serum of subjects with clinical evidence of liver disease and correlated these measurements to the levels of vitamin D binding protein and albumin. These subjects when compared to normal individuals had lower total 25OHD levels, higher percent free 25OHD levels, but equivalent free 25OHD levels. These subjects also had reduced vitamin D binding protein and albumin concentrations.

Low blood mononuclear cell magnesium in intensive cardiac care unit patients.

Magnesium deficiency may play a role in the pathogenesis of atherosclerosis, cardiac arrhythmias, and coronary spasm. Because less than 1% of magnesium (Mg) is extracellular, the serum magnesium (sMg) does not always accurately reflect intracellular Mg stores. To determine the frequency of Mg deficiency in patients with cardiovascular disease, we measured blood mononuclear cell Mg content (mMg) and sMg concentrations in 104 unselected patients admitted to our intensive cardiac care unit (CCU).

TmMg and renal Mg threshold in normal man and in certain pathophysiologic conditions.

The TmMg and renal Mg threshold were assessed in normal subjects and in a number of pathological conditions. The TmMg in normal subjects was 1.4 mg/100 ml glomerular filtrate (GF) 1.

Serum protein binding of 1,25-dihydroxyvitamin D: a reevaluation by direct measurement of free metabolite levels.

Using the technique of centrifugal ultrafiltration isodialysis to measure the free concentration of 1,25-dihydroxyvitamin D [1,25-(OH)2D], we determined the affinity of serum proteins for 1,25-(OH)2D both by Scatchard analysis (increasing ligand concentration at fixed binding site concentrations) and by a novel analysis in which the binding site concentrations were varied (serial dilution) at fixed ligand concentrations. The high affinity binding constant in serum for 1,25-(OH)2D was 3.7 X 10(7) M-1 by Scatchard analysis and 4.

Low serum concentrations of 1,25-dihydroxyvitamin D in human magnesium deficiency.

The effect of magnesium deficiency on vitamin D metabolism was assessed in 23 hypocalcemic magnesium-deficient patients by measuring the serum concentrations of 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D [1,25-(OH)2D] before, during, and after 5-13 days of parenteral magnesium therapy. Magnesium therapy raised mean basal serum magnesium [1.0 +/- 0.

Hypercalcemia in leprosy.

We report a case of hypercalcemia in a patient with leprosy. Aminoterminal parathyroid hormone and 25-hydroxy-cholecalciferol concentrations were suppressed. Urinary hydroxyproline concentrations were elevated.

Intravenous etidronate in the management of malignant hypercalcemia.

The treatment of hypercalcemia remains a common problem in the management of many patients with cancer. We have used intravenously administered etidronate disodium as a therapy for hypercalcemia in 26 patients with malignant disease. Patients with persistent hypercalcemia despite adequate hydration and a serum creatinine level less than or equal to 1.

Parenteral magnesium tolerance testing in the evaluation of magnesium deficiency.

Magnesium deficiency is a common clinical condition, frequently present even with normal serum magnesium (S-Mg) concentrations. We have studied retention of a low-dose (0.2 mEq/kg lean body weight), intravenously administered magnesium load in 6 hypomagnesemic patients and 18 normomagnesemic alcoholics as compared with 16 normal subjects.