The Effect of Pair-feeding or Magnesium and Calcium Deficiency on Insulin Sensitivity in Rats

Abstract

Magnesium deficiency enhances insulin sensitivity in rats whereas it reduces insulin sensitivity in humans. Magnesium deficiency causes hypocalcemia in humans while the hypocalcemia is not observed in magnesium-deficient rats. In the present study, we examined the effect of pair-feeding or magnesium deficiency with calcium deficiency on insulin sensitivity in rats. Rats were pair-fed control diets or magnesium and/or calcium deficient diets for three weeks before intravenous insulin tolerance test (IVITT).

Magnesium deficiency significantly (P<0.05) increased glucose disappearance rate (Kitt) from plasma and decreased area under the curve (AUC) of plasma glucose in IVITT. Pair-feeding did not affect Kitt and AUC. Magnesium and calcium deficiency enhanced insulin sensitivity as well as magnesium deficiency alone. These results suggest that magnesium deficiency enhances insulin sensitivity not via the reduction of feed intake and the disturbance of calcium metabolism.