Does Metformin Cause Blood Sugar To Rise Initially?

My husband started Metformin on Jan 29th evening dose. His last recorded blood sugar before starting new med was 145. Since starting, his blood sugars have running about 245, except yesterday it went up to 358, that was without eating his snacks & carbs. He refused to go to the hospital because he had no symptoms. This morning it was 199. He feels better than he has in weeks. Back on his diet & exercising. He had gotten off his diet and normal exercise routine while remodeling our kitchen. My question is: Can metformin cause your blood sugar to go up during the first weeks of dosing?