Diabetes Talking

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Low serum magnesium level linked to type 2 diabetes in white adults WESTPORT, Oct 22 (Reuters Health) – Among whites, but not blacks, a low serum magnesium level directly and significantly predicts incident type 2

diabetes,         L. Resnick found that faulty magnesium metabolism was characteristic of all of the manifestations of Syndrome X, including hyperinsulinemia. Russ Farris Prog Cardiovasc Dis 1999 Jul-Aug;42(1):1-22 The cellular ionic basis of hypertension and allied clinical conditions. Resnick L University Vascular Center, Wayne State University Medical Center, Detroit, MI, USA. Two central concepts of human hypertensive disease remain poorly understood: (1) elevated blood pressure as merely one component of an underlying systemic condition, characterized by multiple defects in diverse tissues (eg, "Syndrome X"), and (2) the heterogeneity of hypertension, in which different and even opposite clinical responses to different dietary and drug therapies are routinely observed among equally hypertensive subjects. To help explain these clinical phenomena, a unifying "ionic hypothesis" is proposed, in which steady-state elevations of cytosolic free calcium and suppressed intracellular free magnesium levels, characteristic features of all hypertension, concomitantly alter the function of many tissues. In blood vessels this causes vasoconstriction, arterial stiffness, and/or hypertension; in the heart, cardiac hypertrophy; in platelets, increased aggregation and thrombosis; in fat and skeletal muscle, insulin resistance; in pancreatic beta cells, other endocrine tissues, and sympathetic neurons, potentiated stimulus-secretion coupling resulting in hyperinsulinemia, increased sympathetic nerve activity, and so on. Furthermore, an analysis of cellular biochemical, dietary-nutrient, and hormonal factors that normally regulate steady-state levels of these intracellular ions suggests an ionic equivalent to Laragh’s volume-vasoconstriction analysis of hypertension. This provides a cellular-based explanation for the heterogeneity of hypertension and a rational basis for individualizing dietary and drug recommendations among different hypertensive subjects.

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Low serum magnesium level linked to type 2 diabetes in white adults WESTPORT, Oct 22 (Reuters Health) – Among whites, but not blacks, a low serum magnesium level directly and significantly predicts incident type 2 diabetes, according to a multicenter US team. But there does not appear to be a relationship between dietary intake of magnesium and the incidence of type 2 diabetes. Dr. Frederick L. Brancati, of Johns Hopkins University in Baltimore, and others followed for 6 years 12,128 adults, 45 to 64 years of age, who were enrolled in the Atherosclerosis Risk in Communities Study (ARIC). They recorded fasting serum magnesium level and dietary magnesium intake at baseline. The researchers used four criteria to define incident type 2 diabetes: self-reported diagnosis, use of medication to treat diabetes, fasting glucose level of 7.0 mmol/L or nonfasting glucose of 11.1 mmol/L or higher. In white subjects, the researchers detected "…a strong, graded, inverse relationship between incidence rates of type 2 diabetes and serum magnesium levels." They did not observe any such association in blacks. Dr. Brancati and his associates speculate that a relationship might have been observed if more blacks had been enrolled in the study. In an interview with Reuters Health, one of Dr. Brancati’s colleagues, W.H. Linda Kao, a postdoctoral fellow at Johns Hopkins, said that the lack of association between serum magnesium and type 2 diabetes in blacks suggests that not all cases of type 2 diabetes have the same cause. "It’s not impossible to hypothesize that there are different types of diabetes…" that cause the same symptoms, she said. The researchers also found that "…there was no association between dietary magnesium intake and incident type 2 diabetes in black or white participants," the researchers write. This is in contrast to previous findings from the Nurses’ Health study, according to Kao. Both studies relied on food frequency questionnaires, but the ARIC participants, since they were not all healthcare professionals, may not have been as accurate, she said. This may have hidden any relationship between magnesium intake and type 2 diabetes, according to Kao. "We can’t make any recommendations on magnesium intake…" based on this study, she said. "[W]hether pharmacological doses of magnesium used as dietary supplements can reduce the long-term risk for type 2 diabetes remains to be investigated," the researchers conclude. According to Dr. Trevor J. Orchard, of the Rangos Research Center in Pittsburgh, Pennsylvania, there is a "…fairly sound physiological basis for suspecting that serum magnesium may be related to the development of type 2 diabetes mellitus." However, the balance of evidence suggests that "…serum or dietary magnesium is unlikely to be a major factor in the pathogenesis of all cases of type 2 diabetes mellitus," he writes in an editorial that accompanies the study. While the role of magnesium in type 2 diabetes deserves further study, "…no change is needed in the guidelines of the American Diabetes Association, which call for magnesium supplementation only in cases of frank deficiency," Dr. Orchard concludes.

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