Review Question - QID 216684

A 71-year-old man presents to his primary care physician with progressive memory loss over the past 2 years. His wife says that he woke up one morning and was not sure where he placed his keys, but she attributed it to him getting older. However, he continued to be forgetful about where he placed belongings. About 10 months later, he forgot the names of his grandchildren and still calls them the wrong names. Finally, about 3 months ago he started repeatedly getting lost while driving to work and made the decision to retire. In between these episodes, the patient's memory has been stable. His past medical history is significant for hypertension, type 2 diabetes, and hyperlipidemia. He has smoked 1 pack of cigarettes per day for the last 40 years. His temperature is 98.7°F (37.1°C), blood pressure is 155/95 mmHg, pulse is 88/min, respirations are 13/min, and O2 saturation on room air is 99%. Physical exam reveals a man who walks with a steady gait. He has 5/5 strength in his upper and lower extremities. Cranial nerves II-XII are intact. The patient has no sensory abnormalities detected. A recent hemoglobin A1c was 6.9%. Which of the following treatments would provide the greatest benefit for this patient's underlying condition?