A 27-year-old woman is evaluated for management of her type 1 diabetes mellitus. She was diagnosed 10 years ago. She has no known complications from her diabetes. She eats a healthy diet and exercises an average of 60 minutes per day in the evening. She takes insulin glargine and insulin aspart. She is adherent with her insulin regimen and checks her blood glucose level three to five times per day. Her average blood glucose value is 125 mg/dL (6.9 mmol/L), with fasting glucose values ranging from 80 to 150 mg/dL (4.4-8.3 mmol/L). She routinely measures her 2-hour postprandial glucose values, and they are consistently less than 150 mg/dL (8.3 mmol/L). She has several overnight blood glucose values ranging from 90 to 140 mg/dL (5.0-7.8 mmol/L). Her hemoglobin A1c values over the last 6 months have been 7.3% to 7.5%. She is discouraged that her hemoglobin A1c values remain above 7.0%.
Laboratory studies, including creatinine and complete blood count, are normal.
Which of the following is the most appropriate management of her elevated hemoglobin A1c level?