From the Guidelines
High fasting insulin, known as hyperinsulinemia, should be treated with lifestyle modifications and metformin as the first line of treatment, as it improves insulin sensitivity and reduces the risk of cardiovascular events and death 1. The primary cause of high fasting insulin is insulin resistance, where cells don't respond properly to insulin. This condition often develops from excess body weight, physical inactivity, poor diet high in refined carbohydrates and sugars, genetic factors, or certain medications.
Key Factors to Consider
- Excess body weight
- Physical inactivity
- Poor diet
- Genetic factors
- Certain medications Treatment focuses on lifestyle modifications including:
- Weight loss through a balanced diet low in refined carbohydrates and sugars
- Regular exercise (aim for 150 minutes of moderate activity weekly)
- Stress management
- Adequate sleep Medications may be prescribed if lifestyle changes aren't sufficient, including:
- Metformin (starting at 500mg once daily, potentially increasing to 1000mg twice daily)
- GLP-1 receptor agonists like semaglutide (Ozempic, Wegovy) or liraglutide (Victoza, Saxenda) that can help with weight loss and insulin regulation Regular monitoring of blood glucose levels is important, as hyperinsulinemia often precedes type 2 diabetes. The underlying mechanism involves the pancreas overproducing insulin to compensate for cells' resistance, which eventually leads to pancreatic fatigue and potentially diabetes if left untreated 1.
Additional Considerations
- Basal insulin may be initiated at 10 units or 0.1 to 0.2 units/kg of body weight, typically used with metformin and perhaps 1 additional noninsulin agent 1
- Combination injectable therapy should be considered to reduce postprandial glucose excursions, including a GLP-1 receptor agonist or prandial insulin 1
From the Research
Causes of High Fasting Insulin
- High fasting insulin can be caused by insulin resistance, which is often associated with obesity and physical inactivity 2, 3
- Insulin resistance can lead to an increase in fasting serum insulin levels, as the body tries to compensate for the reduced sensitivity to insulin 2
- Other factors, such as genetic predisposition, can also contribute to insulin resistance and high fasting insulin levels 4
Treatment of High Fasting Insulin
- Lifestyle modifications, including a balanced diet and increased physical activity, can help improve insulin sensitivity and reduce fasting insulin levels 2, 3
- Metformin, a medication commonly used to treat type 2 diabetes, has been shown to improve insulin sensitivity and reduce fasting insulin levels in individuals with insulin resistance 5, 6, 4
- A combination of lifestyle modifications and metformin therapy may be an effective approach to improving insulin sensitivity and reducing fasting insulin levels, regardless of genetic predisposition 4
Monitoring and Assessment
- The homeostasis model of insulin resistance (HOMA-IR) index can be used to assess insulin sensitivity and monitor the effectiveness of lifestyle interventions 2
- Fasting serum insulin concentrations and glucose infusion rates can also be used to assess insulin sensitivity and monitor the effectiveness of treatment 2, 5