Can Cortisone Injection Cause Elevated Blood Sugar Levels?

My husband is a Type II DM but off of Metformin for past 6 months. Sugars fasting never higher than 100. Been suffering for past several months with a "foot deformation". Was given a cortisone injection on 11/17 and again 2/2/15. No side effects other than increased urination through the night but tested blood sugar and it has been 400 to 444 twice and 239 fasting this AM. Could the shot be the cause and if so how long should we expect high sugars