Can metformin (metformin hydrochloride) be prescribed for prediabetes?

From the Guidelines

Yes, metformin can be prescribed for prediabetes, especially for individuals with a high risk of developing type 2 diabetes, such as those with a BMI ≥35 kg/m², aged 25-59 years, or with a history of gestational diabetes mellitus. Typically, healthcare providers may prescribe metformin at a starting dose of 500 mg once daily, gradually increasing to 500-850 mg twice daily as tolerated 1. This medication helps improve insulin sensitivity and reduces glucose production by the liver, which can help prevent progression to type 2 diabetes. Metformin is most commonly recommended for individuals with prediabetes who have additional risk factors such as a BMI over 35, age under 60, or a history of gestational diabetes. Lifestyle modifications including diet changes and increased physical activity remain the first-line approach, with metformin serving as an adjunct therapy.

Some key points to consider when prescribing metformin for prediabetes include:

• The medication should be considered for individuals with a high risk of developing type 2 diabetes, as identified by factors such as BMI, age, and history of gestational diabetes mellitus 1.
• The starting dose of metformin is typically 500 mg once daily, with gradual increases to 500-850 mg twice daily as tolerated 1.
• Metformin can help improve insulin sensitivity and reduce glucose production by the liver, which can help prevent progression to type 2 diabetes 1.
• Lifestyle modifications, including diet changes and increased physical activity, remain the first-line approach for preventing type 2 diabetes, with metformin serving as an adjunct therapy 1.
• Potential side effects of metformin include gastrointestinal issues like diarrhea and nausea, which often improve over time, and regular monitoring of kidney function and vitamin B12 levels is necessary while on this medication 1.

It's also important to note that metformin has been shown to be effective in preventing type 2 diabetes in certain populations, such as those with a history of gestational diabetes mellitus, and may be cost-saving over a 10-year period 1. However, the medication should be used with caution in individuals with certain health conditions, such as kidney disease, and regular monitoring of kidney function and vitamin B12 levels is necessary while on this medication 1.

Overall, metformin can be a useful medication for preventing type 2 diabetes in individuals with prediabetes, especially those with a high risk of developing the disease. However, lifestyle modifications, including diet changes and increased physical activity, remain the first-line approach, and metformin should be used as an adjunct therapy.

From the Research

Metformin Prescription for Prediabetes

• Metformin can be prescribed for patients with prediabetes, particularly those with a BMI ≥ 35 kg/m2, aged < 60 years, or women with a history of gestational diabetes 2, 3.
• The American Diabetes Association recommends metformin therapy as a consideration for individuals with these characteristics 2.
• Studies have shown that metformin can decrease the likelihood of progression to diabetes in high-risk individuals, with greater beneficial effects in people with higher baseline Body Mass Index (BMI) and higher Fasting Plasma Glucose (FPG) 4.
• Metformin has also been shown to be cancer and cardio-protective, and has a long-standing safety and tolerability profile 4, 5.

Prescription Rates and Guidelines

• Despite the potential benefits, few patients with prediabetes receive a metformin prescription, with overall prescription rates ranging from 2.4% to 8.1% in different studies 2, 3.
• The National Institute for Clinical Excellence, UK has recommended the use of metformin in prevention of type 2 diabetes in adults at high risk who fail to adhere to lifestyle changes 4.
• The American Diabetes Association and European Association for the Study of Diabetes consensus guidelines recommend metformin as first-line foundation therapy, in addition to lifestyle interventions, for the management of hyperglycaemia in type 2 diabetes 5.

Therapeutic Use of Metformin

• Metformin enhances the action of insulin in liver and skeletal muscle, and its efficacy for delaying or preventing the onset of diabetes has been proven in large, well-designed, randomised trials 6.
• Decades of clinical use have demonstrated that metformin is generally well-tolerated and safe, with a low risk of lactic acidosis and no significant weight gain 5, 6.
• Metformin can be used as a therapeutic option for prediabetes and diabetes prevention, particularly in individuals who are unable to comply with lifestyle advice or have a high risk of progressing to type 2 diabetes 4, 6.