Patient Letter: Starting Metformin for Prediabetes
Dear Patient,
Based on your A1C of 6.7%, you have prediabetes, not diabetes, and I do not recommend starting metformin at this time. Instead, I strongly recommend focusing on intensive lifestyle modifications as your first-line treatment, which has been proven more effective than medication for preventing diabetes 1.
Understanding Your A1C Result
- Your A1C of 6.7% falls in the prediabetes range (5.7-6.4% or 6.0-6.4% depending on the definition used) 1
- This means your blood sugar is higher than normal but not yet in the diabetes range (which would be ≥6.5%) 2
- Importantly, approximately two-thirds of people with prediabetes never develop diabetes, and about one-third return to normal glucose levels without medication 3
Why Lifestyle Changes Come First
Intensive lifestyle modification is more effective than metformin for preventing diabetes progression 1. The evidence shows:
- Lifestyle changes (calorie restriction, ≥150 minutes/week of physical activity, self-monitoring, and motivational support) reduced diabetes incidence by 6.2 cases per 100 person-years over 3 years 1
- Metformin reduced diabetes incidence by only 3.2 cases per 100 person-years over the same period 1
- This means lifestyle modification is nearly twice as effective as metformin 1
Your Lifestyle Action Plan
You should focus on these specific interventions:
- Exercise: Engage in at least 150 minutes per week of moderate-to-vigorous physical activity 1
- Weight loss: Aim for a 7-10% reduction in body weight if you are overweight 2
- Diet: Focus on nutrient-dense, high-quality foods and decrease consumption of calorie-dense, nutrient-poor foods, particularly sugar-added beverages 2
- Self-monitoring: Track your food intake, physical activity, and weight regularly 1
When Would Metformin Be Considered?
Metformin would be most appropriate for you if you have specific high-risk features 1:
- You are younger than 60 years old AND have a BMI ≥35 kg/m²
- Your fasting blood glucose is ≥110 mg/dL (not just A1C)
- Your A1C is ≥6.0% AND you have a history of gestational diabetes
- You have tried intensive lifestyle modification for 3-6 months without improvement
Even in these high-risk groups, lifestyle modification should still be the foundation of your treatment 1.
Important Considerations
- You are not at risk for diabetes complications at this stage 3
- Starting medication now would mean potentially taking it for the rest of your life with no immediate benefit except lowering already sub-diabetes glucose levels 3
- Recent evidence shows that adding metformin to lifestyle changes provides only modest additional benefit in reducing A1C (a small 0.10% reduction) 4
Follow-Up Plan
- Recheck your A1C in 3 months to assess your response to lifestyle changes 5
- If your A1C remains elevated or increases despite intensive lifestyle efforts, we will reassess whether metformin is appropriate 3
- We will also monitor other cardiovascular risk factors (blood pressure, cholesterol, smoking status), which may be more important than your glucose level at this stage 2
The Bottom Line
Your prediabetes diagnosis is a wake-up call to make important lifestyle changes now, not necessarily to start medication 1. The evidence strongly supports that you have the best chance of preventing diabetes and improving your long-term health through diet, exercise, and weight management rather than medication alone.
Please schedule a follow-up appointment in 3 months so we can reassess your progress and A1C level. If you have questions about implementing these lifestyle changes or need additional support, please contact our office.
Sincerely,
Your Healthcare Provider