What is the first line treatment for a patient newly diagnosed with diabetes mellitus, with a Hemoglobin A1C (HbA1C) of 7.9 and a Body Mass Index (BMI) of 34?

First-Line Treatment for Newly Diagnosed Type 2 Diabetes with HbA1c 7.9% and BMI 34

C - Metformin is the correct first-line treatment for this patient, combined with lifestyle modifications including physical activity and weight loss counseling. 1

Rationale for Metformin as First-Line Therapy

Metformin is the preferred initial glucose-lowering medication for most people with type 2 diabetes and should be added to lifestyle measures in newly diagnosed patients. 1 This recommendation is based on:

• Efficacy and safety profile: Metformin effectively lowers HbA1c by approximately 1-1.5%, which would bring this patient's HbA1c from 7.9% toward the target range of 7-8% 1

• Weight considerations: Metformin is weight-neutral or associated with modest weight loss (mean -8.4 lbs in clinical trials), making it particularly appropriate for this patient with BMI 34 2

• Cardiovascular benefits: A UKPDS substudy showed benefits of initial treatment with metformin on clinical outcomes related to diabetes in overweight/obese adults, with less hypoglycemia and weight gain than insulin or sulfonylureas 1

• Cost-effectiveness: Metformin is inexpensive with extensive clinical experience 1

• Low hypoglycemia risk: Metformin does not increase the risk of hypoglycemia when used as monotherapy 1

Why Other Options Are Incorrect

DPP-4 inhibitors (Option A) are not first-line therapy. They are reserved for combination therapy when metformin monotherapy fails to achieve glycemic targets after 3 months 1

Liraglutide (Option B), a GLP-1 receptor agonist, is not recommended as initial monotherapy. While GLP-1 agonists offer weight loss benefits and cardiovascular protection, guidelines specify they should be added as second-line therapy or considered for specific comorbidities (established ASCVD, heart failure, or CKD) 1

Sulfonylureas (Option D) are not preferred first-line agents due to:

• Weight gain risk 1
• Higher hypoglycemia risk 1
• Higher secondary failure rates compared to metformin 1
• Less favorable long-term outcomes in overweight/obese patients 1

Initial Management Algorithm

Step 1: Initiate lifestyle modifications immediately 1

• Counsel patient to lose at least 5% of body weight 1
• Prescribe at least 150 minutes/week of moderate physical activity 1
• Limit non-academic screen time to less than 2 hours daily 1

Step 2: Start metformin at or soon after diagnosis 1

• Initial dosing can be titrated up to 2000-2500 mg daily as tolerated 2
• Monitor for gastrointestinal side effects, which are typically transient 1

Step 3: Monitor HbA1c every 3 months 1

• If HbA1c target (7-8%) is not achieved after 3 months, add a second agent 1
• Given this patient's obesity (BMI 34), a GLP-1 receptor agonist would be the preferred second agent for additional weight loss and cardiovascular benefits 1

Critical Caveats

Contraindications to metformin: Avoid in patients with advanced renal insufficiency (though can be used with dose reduction down to GFR 30-45 mL/min), alcoholism, or conditions predisposing to lactic acidosis 1

When to consider insulin instead: Insulin therapy should be initiated if the patient presents with random glucose ≥250 mg/dL, HbA1c >9%, ketosis, or diabetic ketoacidosis 1. This patient's HbA1c of 7.9% does not meet these criteria 1

Monitoring during treatment: Assess adherence and re-emphasize lifestyle measures at follow-up visits every 3-6 months 1