HYPERTENSION AND PERIPHERAL INSULIN RESISTANCE POSSIBLE MEDIATING ROLE OF INTRACELLULAR FREE MAGNESIUM

To investigate the association of hypertension and insulin resistance, we utilized 31P-NMR speetros-copy to noninvasively assess intracellular free magnesium levels (Mgif) in erythrocytes of normotensive (n = 20) and essential hypertensive (n = 20) subjects given an oral 100 g glucose load. In hypertensive compared with normotensive subjects, fasting glucose and insulin levels were similar, but the integrated insulinemic responses to glucose were 45% greater (312 ± 13.4 v 215 ± 7.5?U/mL, P <. 001). In hypertension, Mgiflevels were significantly reduced (183 ± 9 v 251 ± 9?mol/L, P <. 001), and for all subjects were closely and inversely related to systolic (r = –0.77, P <. 001) and diastolic (r = -0.81, P <. 001) blood pressures, and to the integrated insulin response (r = –0.72, P <. 001). Furthermore, while insulin responses were also related to the underlying systolic (r = 0.69, P <. 001) and diastolic (r =. 73, P <. 001) pressures, these relations were no longer significant when adjusted for Mgiflevels. We hypothesize that hypertension and peripheral insulin resistance may be different clinical expressions of a common abnormal intracellular ionic environment, characterized at least in part by suppressed levels of intracellular free magnesium. © 1990 by the American Journal of Hypertension, Ltd.