From the Guidelines
Stopping metformin without consulting a healthcare provider is not recommended, even with an A1C of 5.5, as it may lead to increased blood sugar levels and decreased insulin sensitivity. While an A1C of 5.5 is within the normal range (below 5.7%), prediabetes management often involves both lifestyle modifications and medication, as suggested by the Diabetes Prevention Program 1. Metformin may be contributing to the improved A1C level, and stopping it could potentially lead to blood sugar increases.
The American Diabetes Association recommends considering metformin therapy for prevention of type 2 diabetes in adults with prediabetes, especially those with higher fasting plasma glucose and A1C levels 1. The decision to stop metformin should be based on individual factors, including overall health, weight, diet, exercise habits, family history, and how long blood sugar has been well-controlled.
If the provider does approve stopping metformin, they will likely recommend continued lifestyle modifications (healthy eating, regular physical activity, weight management) and more frequent blood sugar monitoring to ensure levels remain stable 1. Metformin works by reducing glucose production in the liver and improving insulin sensitivity in the body's tissues, so removing this support requires careful consideration and monitoring.
Some key points to consider when deciding whether to stop metformin include:
- The patient's individual risk factors for developing type 2 diabetes, such as family history and BMI 1
- The potential benefits of continued metformin therapy, including reduced risk of cardiovascular disease and improved insulin sensitivity 1
- The importance of lifestyle modifications, including healthy eating and regular physical activity, in maintaining stable blood sugar levels 1
- The need for regular blood sugar monitoring to ensure levels remain stable after stopping metformin 1
From the Research
Stopping Metformin for Prediabetes with A1C 5.5
- The decision to stop metformin for a prediabetic individual with an A1C of 5.5 should be based on various factors, including the individual's risk of progressing to diabetes and their response to lifestyle modifications 2, 3.
- According to a study published in JAMA, metformin is most effective for women with prior gestational diabetes and for individuals younger than 60 years with a body mass index of 35 or greater, fasting plasma glucose level of 110 mg/dL or higher, or HbA1c level of 6.0% or higher 2.
- However, another study published in Diabetes Care suggests that metformin should not be used to treat prediabetes, as approximately two-thirds of people with prediabetes do not develop diabetes, and metformin treatment will not affect the microvascular complications of diabetes 3.
- Lifestyle modifications, such as calorie restriction, increased physical activity, self-monitoring, and motivational support, have been shown to be effective in decreasing the incidence of diabetes and improving glycemic control in individuals with prediabetes 2, 4, 5, 6.
- A meta-analysis of randomized controlled trials found that adding metformin to lifestyle interventions significantly reduced HbA1c levels and the incidence of type 2 diabetes, compared to lifestyle interventions alone 5.
- Another systematic review and meta-analysis found that lifestyle intervention was an efficacious, safe, and cost-effective measure to reduce the risk of progression to type 2 diabetes in people diagnosed with prediabetes 6.
Considerations for Stopping Metformin
- The individual's A1C level of 5.5 is below the threshold for prediabetes, which is defined as an HbA1c level of 5.7% to 6.4% or 6.0% to 6.4% 2.
- The individual's response to lifestyle modifications and their risk of progressing to diabetes should be taken into account when deciding whether to stop metformin 2, 3.
- Regular monitoring of the individual's glycemic control and cardiovascular risk factors is necessary to determine the best course of treatment 2, 3, 5, 6.