Serum total and ionized magnesium concentrations and urinary fractional excretion of magnesium in cats with diabetes mellitus and diabetic ketoacidosis.
OBJECTIVE
To determine magnesium (Mg) status in cats with naturally acquired diabetes mellitus (DM) and diabetic ketoacidosis (DKA), evaluate changes in Mg status after treatment for DKA, and correlate Mg status with systemic blood pressure and degree of glycemic control.


METHODS
Case series and cohort study.


METHODS
12 healthy cats (controls), 21 cats with DM, and 7 cats with DKA.


METHODS
Serum total magnesium (tMg) and ionized magnesium (iMg) concentrations and spot urinary fractional excretion of magnesium (FEmg) were determined, using serum and urine samples obtained from all cats when they were entered in the study and from cats with DKA 12, 24, and 48 hours after initiating treatment. Indirect blood pressure and degree of glycemic control were determined in 10 and 21 cats with DM, respectively.


RESULTS
Initially, 2 and 13 cats with DM and 1 and 4 cats with DKA had serum tMg and iMg concentrations, respectively, less than the low reference limit (mean-2 SD) determined for controls. In cats with DKA, serum tMg concentration decreased significantly over time after initiating treatment. Urinary FEmg was significantly higher in cats with DM or DKA, compared with controls. Systemic hypertension was not detected nor was there a correlation between Mg status and degree of glycemic control in cats with DM.


CONCLUSIONS
Hypomagnesemia was a common finding in cats with DM and DKA and was more readily identified by measuring serum iMg concentration than tMg concentration. The clinical ramifications of hypomagnesemia in such cats remain to be determined.
Norris
C R
CR
Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616-8734, USA.
Nelson
R W
RW
Christopher
M M
MM
D000818:Animals; D001794:Blood Pressure; D016022:Case-Control Studies; D002371:Cat Diseases / Q000097:blood* / Q000503:physiopathology / Q000652:urine*; D002415:Cats; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000097:blood / Q000652:urine / Q000662:veterinary*; D016883:Diabetic Ketoacidosis / Q000097:blood / Q000652:urine / Q000662:veterinary*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D008274:Magnesium / Q000097:blood* / Q000652:urine*; D008297:Male; D012016:Reference Values; D013047:Specific Pathogen-Free Organisms
D006442:Glycated Hemoglobin; D008274:Magnesium