Measurement of magnesium absorption and retention in type 2 diabetic patients with the use of stable isotopes.
BACKGROUND
Magnesium deficiency has been associated with type 2 diabetes and may reduce insulin sensitivity and impair glucose tolerance. The etiology of magnesium depletion in diabetes is unclear. Animal studies suggest that diabetes may impair magnesium absorption; however, there are no published data on magnesium absorption in humans with diabetes.


OBJECTIVE
Magnesium absorption from a test meal and the excretion and retention of magnesium were compared between patients with type 2 diabetes and healthy control subjects.


METHODS
A meal labeled with 10 mg (26)Mg isotopic label was administered, and stool and urine samples were collected for 10 and 6 d, respectively. Apparent absorption was calculated as the difference between the oral dose of (26)Mg isotopic label and the total amount of the isotopic label excreted in the feces. Magnesium retention was calculated from the apparent absorption and urinary excretion of (26)Mg isotopic label in the 6 d after administration.


RESULTS
Mean (+/- SD) values for fractional magnesium absorption in the diabetic patients and the control subjects were 59.3 +/- 7.0% and 57.6 +/- 8.5%, respectively (NS). Mean (+/- SD) urinary magnesium excretion values in the diabetic patients and the control subjects were 11.2 +/- 2.6% and 11.7 +/- 3.8%, respectively (NS); retention values were 54.2 +/- 7.1% and 51.4 +/- 6.1%, respectively (NS).


CONCLUSIONS
Dietary magnesium absorption and retention are not impaired in patients with reasonably well-controlled type 2 diabetes.
Wälti
Monika K
MK
Laboratory for Human Nutrition, Institute of Food Science and Nutrition, Swiss Federal Institute of Technology Zurich, Rüschlikon, Switzerland. monika.waelti@ilw.agrl.ethz.ch
Zimmermann
Michael B
MB
Walczyk
Thomas
T
Spinas
Giatgen A
GA
Hurrell
Richard F
RF
D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism*; D005243:Feces / Q000737:chemistry; D006801:Humans; D007408:Intestinal Absorption; D007554:Isotopes / Q000378:metabolism / Q000652:urine; D008274:Magnesium / Q000378:metabolism* / Q000652:urine; D008275:Magnesium Deficiency / Q000209:etiology; D008875:Middle Aged
D007554:Isotopes; D008274:Magnesium