MKSAP quiz: first-line medication for type 2 diabetes
This month's quiz asks readers to choose a medication for a patient who has been managing her type 2 diabetes with lifestyle modifications.
A 52-year-old woman presents for follow-up evaluation after being diagnosed with type 2 diabetes mellitus 6 weeks ago. Her initial HbA1c level was 8.0%. Management at this time is with lifestyle modifications. She has worked closely with a diabetes educator and a nutritionist since her diagnosis. She has lost 3.2 kg (7 lb) by making changes to her diet and activity level. Review of her blood glucose log for the past 2 weeks shows preprandial blood glucose values in the 150 to 160 mg/dL (8.3-8.9 mmol/L) range and several 2-hour postprandial blood glucose values of 190 to 200 mg/dL (10.5-11.1 mmol/L). Her only other medical problem is hypertension for which she takes lisinopril.
On physical examination, blood pressure is 125/70 mm Hg and pulse rate is 74/min. BMI is 28. There is no evidence of diabetic retinopathy. She has normal monofilament and vibratory sensation in her extremities.
Except for her blood glucose parameters, basic laboratory studies obtained at the time of her initial diagnosis were normal.
In addition to continuing lifestyle modifications, which of the following is the most appropriate management for this patient's diabetes?
A. Initiate dapagliflozin
B. Initiate glipizide
C. Initiate metformin
D. Initiate sitagliptin
MKSAP Answer and Critique
The correct answer is C. Initiate metformin. This item is available to MKSAP 17 subscribers as item 29 in the Endocrinology section. More information about MKSAP 17 is available online.
The most appropriate management for this patient is to initiate metformin. The patient is early in her diabetes disease course without evidence of microvascular disease. For otherwise healthy adults meeting these criteria, the American Diabetes Association recommends a HbA1c level of less than 7.0%, preprandial glucose values of 70 to 130 mg/dL (3.9-7.2 mmol/L), and 1- to 2-hour postprandial glucose values of less than 180 mg/dL (10 mmol/L). Because the patient has not met these goals, a pharmacologic agent should be added at this time. Lifestyle recommendations consisting of increased physical activity, dietary modifications, and weight loss (if BMI is elevated) are the initial first step in treating diabetes. When lifestyle modifications fail to meet glycemic goals within 6 weeks, metformin is the recommended first-line therapy to be started in conjunction with continued lifestyle modifications. If glycemic goals are not met after 3 months of lifestyle modifications and metformin use, additional agents should be added to the regimen every 3 months until glucose goals are met.
Dapagliflozin, a sodium-glucose transporter-2 (SGLT-2) inhibitor, increases excretion of glucose through the kidney. It is a second-line agent that should be used after lifestyle modifications and metformin fail to reach glycemic goals.
The sulfonylurea glipizide stimulates insulin secretion from the pancreatic beta cells. This agent could improve the patient's postprandial hyperglycemia, but it may also induce weight gain in a patient actively working on weight loss. Glipizide is a second-line agent that should be used after lifestyle modifications and metformin fail to reach glycemic goals.
Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, improves glycemic control by slowing gastric emptying and suppressing glucagon secretion. It is also considered a second-line agent that might be considered if lifestyle modifications and metformin fail to reach glycemic goals.
Key Point
- For most patients with type 2 diabetes mellitus, lifestyle modifications and metformin therapy are the most appropriate initial treatments.