As there are no obvious symptoms for prediabetes, there’s often no reason to suspect you might be prediabetic. However, there are a number of factors that increase your risk of prediabetes. If you recognise any of these risk factors in yourself, you may want to talk to your doctor about your concerns and about testing your blood glucose levels.
Risk Factors
Being Overweight
Being Overweight
If you are overweight or obese (i.e. with a body mass index (BMI) over 25 kg/m2 (or over 23 kg/m2 in Asians) there is more pressure on the body’s ability to use insulin to properly control blood glucose levels.
Lack of Exercise
Lack of Exercise
Physical inactivity can impair glucose control.
Age
Age
You are at a greater risk of prediabetes if you are aged 45 years and over.
Family History
Family History
If your close relatives have diabetes, it is more likely that you will also be at risk of developing diabetes or prediabetes, as both genetic and environmental factors are important.
History of Gestational Diabetes
History of Gestational Diabetes
If you’ve had diabetes during pregnancy or have given birth to a child weighing more than 9 pounds (approximately 4 kg).
Race and Ethnicity
Race and Ethnicity
There is a higher prevalence of type 2 diabetes in certain ethnic groups, including African, Native American, Latin American or Asian/Pacific Islanders.
Hypertension
Hypertension
If you have high blood pressure (i.e. above 140/90 mmHg) you are at an increased risk of developing diabetes.
Cholesterol Level
Cholesterol Level
You are at increased risk if you have high-density lipoprotein (HDL) cholesterol (good cholesterol) below 35 mg/dL (0.90mmol/L) and/or a triglyceride level above 250 mg/dL (2.82 mmol/L).
Polycystic Ovary Syndrome (PCOS)
Polycystic Ovary Syndrome (PCOS)
PCOS occurs when a woman’s hormones are out of balance and has also been linked to increased risk of diabetes.
What tests can tell me if I am prediabetic?
If you think you are at risk of prediabetes, there are tests that can be performed to find out whether you are prediabetic. Your doctor will decide which tests are appropriate. The most common tests are:
Fasting Plasma Glucose
This test checks how your blood glucose levels are maintained after fasting (not having anything to eat or drink except water) for at least 8 hours. This is generally done in the morning after an overnight fast, and your blood is tested to assess the level of glucose present.
Oral Glucose Tolerance Test (OGTT)
This test measures your body’s ability to respond to glucose. After an 8-hour fast, you will be asked to drink a sweet liquid containing a measured amount of glucose (usually 75g). Your blood glucose levels before and 2 hours after this drink (the glucose load) are then measured to understand how your body reacts to the glucose following the fast.
Hemoglobin A1c (HbA1c)
When glucose is in the bloodstream, it naturally attaches to red blood cells, which contain a protein called haemoglobin. These red blood cells are then said to be ‘glycated’. The HbA1c test measures this level of glycated haemoglobin. Red blood cells tend to survive for approximately 4 months before renewal; because of this, the HbA1c test can be used to accurately estimate your average blood glucose levels over the past 2–3 months. This provides a useful longer-term measurement of blood glucose control. There is no need to fast when this test is performed.
What are the criteria for identifying prediabetes?
If you are prediabetic, your blood glucose is raised above normal levels, but is not high enough to be diagnosed with diabetes.1, 9 The exact amount it needs to be raised by to be identified as prediabetic varies slightly in the criteria published by the World Health Organization (WHO) and the American Diabetes Association (ADA).1, 10 The raised blood glucose seen in prediabetes increases the risk of type 2 diabetes.1 Identifying prediabetes now can be your chance to make positive changes and give yourself a second chance.
During the development of diabetes, fasting blood glucose, oral glucose tolerance and HbA1c levels increase.10, 11 Once levels rise into the prediabetic ranges, you are at a greater risk of developing diabetes. If you think you may be prediabetic, your doctor can perform tests to measure your blood glucose levels.
Criteria differences for detecting prediabetes
Criteria for identifying prediabetes |
World Health Organization (WHO) |
American Diabetes Association (ADA) |
| Impaired fasting glucose (IFG) | 6.1 – 6.9 mmol/L (110 – 125 mg/dL) | 5.6 – 6.9 mmol/L (100 – 125 mg/dL) |
| Oral glucose tolerance test (OGTT; blood glucose 2h after of 75g oral glucose) | 7.8 – 11.1 mmol/L (140 – 200 mg/dL) | 7.8 – 11.0 mmol/L (140 – 199mg/dL) |
| HbA1c | Not considered a suitable test for prediabetes | 5.7 – 6.4% |