Oral Magnesium Supplementation Improves Insulin Sensitivity and Metabolic Control in Type 2 Diabetic Subjects

Abstract

OBJECTIVE -To determine whether oral magnesium supplementation (as magnesium chloride [MgCl 2 ] solution) improves both insulin sensitivity and metabolic control in type 2 diabetic subjects with decreased serum magnesium levels. RESEARCH DESIGN AND METHODS-This study was a clinical randomized double-blind placebo-controlled trial. A total of 63 subjects with type 2 diabetes and decreased serum magnesium (serum magnesium levels Յ0.74 mmol/l) treated by glibenclamide received either 50 ml MgCl 2 solution (containing 50 g MgCl 2 per 1,000 ml solution) or placebo daily for 16 weeks. Chronic diarrhea, alcoholism, use of diuretic and/or calcium antagonist drugs, and reduced renal function were exclusion criteria. Homeostasis model assessment for insulin resistance (HOMA-IR) was used as the parameter of insulin sensitivity and glucose and HbA 1c as parameters of metabolic control.RESULTS -At the end of the study, subjects who received magnesium supplementation showed significant higher serum magnesium concentration (0.74 Ϯ 0.10 vs. 0.65 Ϯ 0.07 mmol/l, P ϭ 0.02) and lower HOMA-IR index (3.8 Ϯ 1.1 vs. 5.0 Ϯ 1.3, P ϭ 0.005), fasting glucose levels (8.0 Ϯ 2.4 vs. 10.3 Ϯ 2.1 mmol/l, P ϭ 0.01), and HbA 1c (8.0 Ϯ 2.4 vs. 10.1 Ϯ 3.3%, P ϭ 0.04) than control subjects.CONCLUSIONS -Oral supplementation with MgCl 2 solution restores serum magnesium levels, improving insulin sensitivity and metabolic control in type 2 diabetic patients with decreased serum magnesium levels. Diabetes Care 26:1147-1152, 2003H ypomagnesemia, a frequent condition in patients with diabetes (1,2), could be involved in the development of poor metabolic control and chronic complications (3,4). A large body of evidence that shows a link between hypomagnesemia and reduction of tyrosinekinase activity at the insulin receptor level, which may result in the impairment of insulin action and development of insulin resistance, has been progressively accumulated in previous years (5-10). Although evidence suggests that magnesium supplementation could be useful in the treatment of diabetes and to prevent the development of its chronic complications (11-13), the possible benefits of magnesium administration as an adjuvant factor for the treatment of type 2 diabetes, based in a randomized controlled trial, are scarce (14 -19) and controversial (19).So, the aim of this study was to determine whether oral magnesium supplementation, as magnesium chloride (MgCl 2 ) solution, 2.5 g daily, improves insulin sensitivity and metabolic control in type 2 diabetic subjects with decreased serum magnesium levels. RESEARCH DESIGN AND METHODS -With approval of the protocol by the Mexican Social SecurityInstitute (MSSI) Research Committee and after obtaining informed consent from subjects, a randomized double-blind placebo-controlled trial was carried out.Type 2 diabetic subjects recruited from an outpatient Primary Level Medical Care Office in Durango, a city in Northern Mexico, were eligible to participate in the study if they had decreased serum magnesium levels. Based on previous...

Hypomagnesemia in Patients with Type 2 Diabetes

“…It is interesting that the induction of Mg deficiency has been shown to reduce insulin sensitivity in individuals without diabetes, whereas Mg supplementation during a 4-wk period has been shown to improve glucose handling in elderly individuals without diabetes (18,24). In patients with type 2 diabetes, oral Mg supplementation during a 16-wk period was suggested to improve insulin sensitivity and metabolic control (25). The mechanisms whereby hypomagnesemia may induce or worsen existing diabetes are not well understood.…”

Clinical Consequences and Management of Hypomagnesemia

“…30 -35 Although it has been suggested that Mg 2ϩ deficiency contributes to the induction of diabetes and its associated complica- , and variations in study population complicate these trials. 30,[37][38][39] …”

Magnesium intake and colorectal cancer risk in the Netherlands Cohort Study

“…(Mori et al, 1993). Magnesium plays a role in genomic stability and DNA repair (Hartwig, 2001;Larsson et al, 2005) and may reduce hyperinsulinaemia (Paolisso et al, 1992;Rodriguez-Moran and Guerrero-Romero, 2003), a risk factor for colorectal cancer (Giovannucci, 1995;Schoen et al, 1999). In the Netherlands Cohort Study (NLCS), we investigated colorectal cancer in both sexes in relation to magnesium intake, particularly in overweight subjects, given the suggested beneficial effects of magnesium on insulin resistance (Fung et al, 2003).…”