Question

why are some patients of diabetes treated by giving injections of insulin?

Answer 1

Some patients of diabetes are treated by giving injections of insulin because in diabetes insulin level gets down. So to make the insulin level as usual, injections of insulin are used

Hope that helps

Answer 2

Some diabetic patients are given injections of insulin to regulate sugar levels.  

EXPLANATION:

Insulin is a hormone that is secreted by the pancreas and regulates the sugar level in the blood stream. For a diabetic patient, the insulin is not synthesized in the required quantity by the pancreas and so the sugar levels are not regulated and usually high.

For such patients, insulin injections help in bringing sugar levels to normal level and controlling the sugar levels for the proper functioning of the body.