Urinary magnesium in normotensive and hypertensive adolescents

Abstract

Deficiency of magnesium (Mg) may predispose to arterial hypertension, which is more frequent in males. Investigation of the physiological mechanisms of arterial blood pressure (BP) regulation in both sexes might explain this gender-related difference. Essential hypertension usually manifests in adulthood, but it may have a latent onset in childhood, so investigations of Mg turnover in adolescents might help explain the mechanisms of this disease. This paper presents data on urinary Mg. We monitored urinary Mg (both during day and night) concomitantly with BP (hourly) in normotensive adolescents including girls during different phases of their menstrual cycle. We also monitored urinary Mg in hypertensive boys. The 24-h Mg urinary excretion was significantly higher in normotensive boys than in girls. It exhibited a significant positive (direct) correlation with BP in boys, especially overnight. Mean BP exhibited a significant positive correlation with height in boys. Girls exhibited a significant negative (inverse) correlation between nocturnal urinary Mg excretion and BP during the luteal phase of their menstrual cycle, as well as a significant negative correlation between magnesium urinary excretion and height. 24-h Mg urinary excretion was found to be significantly higher in hypertensive than compared with normotensive boys. Mg excretion was directly related to body weight and BMI in hypertensive boys. Higher urinary excretion of Mg may predispose to Mg deficiency in hypertensive boys.