From the Guidelines
The current definition of Impaired Fasting Glucose (IFG) is a fasting plasma glucose level of 100 mg/dL to 125 mg/dL [ 1 ].
Key Points
- This intermediate category falls between normoglycemia, defined as a fasting plasma glucose level of less than 100 mg/dL, and diabetes, defined as a fasting plasma glucose level of 126 mg/dL or higher [ 1 ].
- The diagnosis of IFG is based on a single fasting plasma glucose measurement, and no specific medication or treatment duration is required for diagnosis, although lifestyle modifications and monitoring are typically recommended.
- It is worth noting that the World Health Organization and numerous other diabetes organizations define the IFG lower limit at 110 mg/dL [ 1 ].
Diagnosis and Recommendations
- The diagnosis of IFG is straightforward and relies on a simple blood test to measure fasting plasma glucose levels [ 1 ].
- Individuals with IFG are at increased risk of developing type 2 diabetes and cardiovascular disease, and therefore, lifestyle modifications such as dietary changes and increased physical activity are often recommended to prevent or delay the onset of these conditions [ 1 ].
From the Research
Definition of Impaired Fasting Glucose (IFG)
- The current definition of Impaired Fasting Glucose (IFG) is a fasting plasma glucose level of 100 to 125 mg/dL (5.6 to 6.9 mmol/L) 2.
- This definition has been supported by various studies, including one that found that a fasting plasma glucose level of ≥100 mg/dL is associated with an increased risk of developing type 2 diabetes 3.
- However, some studies have suggested that the optimal cut-off for IFG may be higher, such as ≥102 mg/dL 3.
- The International Diabetes Federation has also suggested that the 1-hour post-load plasma glucose level may be a useful diagnostic tool for identifying individuals with impaired glucose tolerance and type 2 diabetes 4.
Pathophysiology of IFG
- IFG and impaired glucose tolerance (IGT) share similar underlying pathophysiologies, including insulin resistance and metabolic syndrome 5.
- Factor analysis has shown that the risk factors for IFG and IGT, such as waist-to-hip ratio, triglycerides, and high-density lipoprotein cholesterol, are grouped into similar dimensions 5.
- This suggests that IFG and IGT may be part of a continuum of glucose intolerance, rather than distinct entities 6.
Diagnosis and Intervention
- The diagnosis of IFG is typically made using a fasting plasma glucose test 2.
- Individuals with IFG are at increased risk of developing type 2 diabetes and cardiovascular disease, and may benefit from lifestyle interventions such as weight loss and increased physical activity 6.
- Medications such as metformin and acarbose may also be effective in preventing or delaying the onset of type 2 diabetes in individuals with IFG 2, 6.