Low magnesium risks arrhythmia in diabetes patients
MedWire News: Patients with Type 2 diabetes with low serum magnesium (sMg) concentrations are at significant risk for premature ventricular complexes (PVC), research shows.
"Here, we provide the first supporting evidence that Type 2 diabetes is an important effect modifier of the association between sMg and PVC, with reductions in PVC prevalence across the sMg gradient in Type 2 diabetes only, driving the significant associations observed in the entire population," Liana Del Gobbo (McGill University, Montreal, Quebec, Canada) and colleagues comment.
PVCs are a relatively common electrocardiographic abnormality presenting in individuals with and without overt cardiovascular disease.
In the Framingham Offspring cohort, sMg was significantly inversely associated with prevalence of complex or frequent PVC in adults free from clinically apparent heart disease.
Since Type 2 diabetes is the most common condition associated with low sMg, and Type 2 diabetes significantly increases risk for PVC and sudden cardiac death, the association between sMg and PVC may be modified by diabetes status.
To test this hypothesis the researchers recruited 750 adults of Cree descent from the James Bay region of Quebec.
Holter electrocardiograms recorded heart rate variability and cardiac arrhythmias for 2 consecutive hours.
The researchers found that in those with hypomagnesemia (sMg ≤0.70 mmol/L), the prevalence of PVC was more than twice that of individuals without hypomagnesemia (50 vs 21%).
Of all the hypomagnesemic individuals, 76% had Type 2 diabetes rising to 100% of hypomagnesemic adults with PVC.
There was a significant linear trend for a declining prevalence of PVC with increasing sMg concentration gradient in individuals with Type 2 diabetes only, but not for the wider population.
In multivariate logistic regression analysis the odds ratio for PVC among Type 2 diabetes patients with sMg above 0.70 mmol/L was 0.24 compared with hypomagnesemic individuals, after adjustment for age, gender, community, body mass index, smoking, physical activity, alcohol consumption, kidney disease, antihypertensive and cholesterol-lowering drug use, and blood docosahexaenoic acid concentrations.
"Future interventions to increase sMg concentrations among adults with Type 2 diabetes may confer protection against ventricular arrhythmias," the team comments in Cardiovascular Diabetology.
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By Andrew Czyzewski