From the Guidelines
Prediabetes is diagnosed when blood glucose levels are higher than normal but not high enough to be classified as diabetes, with a range of a fasting blood glucose level between 100 and 125 mg/dL (5.6 to 6.9 mmol/L), or a hemoglobin A1C level between 5.7% and 6.4%, or a 2-hour plasma glucose level between 140 and 199 mg/dL (7.8 to 11.0 mmol/L) during an oral glucose tolerance test, as defined by the most recent guidelines 1. The diagnosis of prediabetes is crucial for early intervention to prevent the progression to type 2 diabetes.
- The criteria for prediabetes include:
- Fasting plasma glucose (FPG) between 100 and 125 mg/dL (5.6 to 6.9 mmol/L)
- 2-hour plasma glucose (2-h PG) during an oral glucose tolerance test (OGTT) between 140 and 199 mg/dL (7.8 to 11.0 mmol/L)
- Hemoglobin A1C (A1C) between 5.7% and 6.4% These values indicate that the body is having difficulty properly processing glucose, often due to developing insulin resistance 1. If an individual falls within these ranges, lifestyle modifications are recommended, including:
- Losing 5-7% of body weight if overweight
- Engaging in at least 150 minutes of moderate physical activity weekly
- Following a balanced diet low in refined carbohydrates and added sugars Regular monitoring of blood glucose levels is essential, as prediabetes can progress to type 2 diabetes if left unaddressed, but with proper intervention, it's often reversible 1.
From the Research
Definition of Prediabetes
The definition of prediabetes is an intermediate stage between normal glucose regulation and diabetes, characterized by:
- A fasting glucose level of 100 to 125 mg/dL 2, 3
- A glucose level of 140 to 199 mg/dL measured 2 hours after a 75-g oral glucose load 2, 3
- A glycated hemoglobin level (HbA1C) of 5.7% to 6.4% or 6.0% to 6.4% 2, 3
Diagnostic Criteria
The diagnostic criteria for prediabetes include:
- Fasting plasma glucose (FPG) between 100 and 125 mg/dL 3
- 2-h plasma glucose during an oral glucose tolerance test (OGTT) between 140 and 199 mg/dL 3
- HbA1C level between 5.7% and 6.4% 3
- 1-h plasma glucose concentration (1hPG) during an OGTT may also be used as an alternative to 2-h plasma glucose concentration (2hPG) 4, 5
Relationship with Glucose and Cardiometabolic Parameters
The relationship between 1hPG and 2hPG with other glucose parameters and cardiometabolic risk markers has been investigated, showing:
- Positive correlation between 1hPG and homeostatic model assessment for insulin resistance (HOMA-IR), fasting plasma glucose (FPG), and glycated haemoglobin (Hb1AC) 5
- Negative correlation between 1hPG and homeostatic model assessment for cell-β function (HOMA-β) 5
- Fair agreement between 1 and 2hPG for prediabetes diagnosis 5
Screening and Diagnostic Recommendations
Screening and diagnostic recommendations for prediabetes include:
- Using the oral glucose tolerance test (OGTT) as a cornerstone for detecting prediabetes and type 2 diabetes (T2DM) 4
- Considering the use of 1-h PG level as an alternative to 2-h PG level for identifying high-risk individuals 4
- Using HbA1C level as a screening tool for newly diagnosed diabetes and pre-diabetes, which may perform better than FPG and 2-h OGTT in certain populations 6