title: Intracellular free magnesium in hypertension: relation to peripheral insulin resistance.
abstract: In order to study the importance of altered intracellular ion metabolism in hypertension, we used 31P nuclear magnetic resonance (NMR) spectroscopy to measure intracellular free magnesium levels in normotensive (n = 19), essential hypertensive (n = 17) and diet-controlled diabetic (n = 6) subjects given a standard 100-g oral glucose load. The intracellular Mg level was significantly lower in hypertensives compared with normotensives (183 +/- 7 versus 232 +/- 10 mumol/l, P less than 0.001), and for all subjects was closely linked to both systolic (r = -0.84, P less than 0.001) and diastolic (r = -0.76, P less than 0.001) pressure. Hypertensives also showed a significantly greater insulinaemic response to glucose loading (P less than 0.001), and intracellular Mg was also closely and inversely linked to the integrated insulin response (r = -0.78, P less than 0.001). Despite the absence of hyperinsulinaemia, diabetics had the lowest intracellular Mg levels (156 +/- 8 mumol/l). Thus, suppressed intracellular Mg is linked to hypertension and to decreased tissue insulin sensitivity, and is not consequent to the hyperinsulinaemia itself. We suggest that intracellular Mg may provide a common pathophysiological basis for understanding the clinical association of hypertension and diabetes mellitus.
authors.affiliation: Cardiovascular Center, Cornell University Medical Center, New York, New York 10021.
authors.forename: L M
authors.initials: LM
authors.lastname: Resnick
authors.forename: R K
authors.initials: RK
authors.lastname: Gupta
authors.forename: H
authors.initials: H
authors.lastname: Gruenspan
authors.forename: J H
authors.initials: JH
authors.lastname: Laragh
mesh_terms: D001794:Blood Pressure; D003593:Cytoplasm / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology; D005951:Glucose Tolerance Test; D006801:Humans; D006973:Hypertension / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism
chemical_list: D008274:Magnesium; D005947:Glucose