A nurse is caring for a client who was prescribed metformin 6 months ago. Which of the following findings indicates a positive response to the medication?

A. The client's high-density lipoprotein level has increased: While metformin can have minor effects on lipid metabolism, an increase in HDL is not the primary therapeutic goal or a direct measure of the medication’s effectiveness in managing type 2 diabetes. B. The client's frequency of incontinence has decreased: Urinary incontinence is not a direct indicator of metformin effectiveness. Changes in incontinence may result from other conditions or medications and do not reflect glycemic control. C. The client's HbA1c has decreased: A decrease in HbA1c indicates improved long-term blood glucose control, which is the primary goal of metformin therapy. Monitoring HbA1c over 2–3 months helps determine how effectively the medication is managing type 2 diabetes. D. The client's iron level has increased: Iron levels are not affected by metformin and do not serve as a measure of its efficacy. Changes in iron would be related to dietary intake, absorption issues, or other medical conditions rather than glucose management.