From the Guidelines
An A1C of 5.6% in a healthy 30-year-old is considered to be at the upper limit of normal and is associated with an increased risk of developing type 2 diabetes, although it falls just below the prediabetic range of 5.7-6.4%. According to the study by 1, an A1C level of 5.6% corresponds to an FPG of 100 mg/dL (5.6 mmol/L), which is considered to be at the threshold for impaired fasting glucose. The study also notes that individuals with an A1C level between 5.5 and 6.0% have a 5-year cumulative incidence of diabetes that ranges from 12 to 25%, which is appreciably higher than the incidence in the general population.
The American Diabetes Association (ADA) has endorsed the use of A1C as a diagnostic and screening tool for diabetes, with an A1C level of 5.7-6.4% considered to be in the prediabetic range 1. While an A1C of 5.6% is not yet in the official prediabetic range, it is still important to take preventive measures to reduce the risk of developing diabetes. Lifestyle modifications, such as maintaining a healthy weight, engaging in regular physical activity, and adopting a balanced diet, are strongly advised. Regular follow-up A1C tests every 1-2 years are also recommended to monitor the individual's risk of developing diabetes.
It is essential to note that the risk of diabetes is a continuum, and an A1C level of 5.6% indicates that blood glucose levels are occasionally elevated, potentially due to developing insulin resistance or decreased insulin production by the pancreas. Early intervention through lifestyle changes can effectively prevent progression to diabetes. As stated in the study by 1, preventive interventions, such as weight loss and physical activity, have been demonstrated to prevent or delay the development of diabetes in people with impaired glucose tolerance.
In terms of specific recommendations, the individual should aim to:
- Maintain a healthy weight or lose 5-7% of body weight if overweight
- Engage in at least 150 minutes of moderate-intensity physical activity weekly
- Adopt a balanced diet rich in vegetables, fruits, whole grains, and lean proteins while limiting processed foods and added sugars
- Have regular follow-up A1C tests every 1-2 years to monitor their risk of developing diabetes.
From the Research
Diagnosis of Diabetes using HbA1c
- The American Diabetes Association and the European Association for the Study of Diabetes recommend a HbA1c level of ≥ 6.5% for the diagnosis of diabetes mellitus 2.
- A HbA1c level of 5.6 is below the diagnostic threshold for diabetes.
- However, it is essential to note that HbA1c levels between 5.7 and 6.4 are considered prediabetic, indicating an increased risk of developing diabetes 2.
Risk of Diabetes with HbA1c 5.6
- Studies have shown that individuals with prediabetic HbA1c levels are at a higher risk of developing type 2 diabetes and cardiovascular disease 3, 4.
- Regular exercise, such as aerobic exercise training (AET) or resistance training (RT), has been shown to improve insulin sensitivity and reduce the risk of developing type 2 diabetes in individuals with prediabetes 4, 5, 6.
- A healthy 30-year-old with a HbA1c level of 5.6 may be considered at risk of developing diabetes, especially if they have other risk factors such as a family history of diabetes, obesity, or a sedentary lifestyle.
Exercise and Diabetes Prevention
- Exercise has been shown to be an effective way to prevent or delay the onset of type 2 diabetes in individuals with prediabetes 3, 4, 5, 6.
- Both AET and RT have been shown to improve glycemic control and reduce insulin resistance in individuals with prediabetes 4, 5, 6.
- A combination of AET and RT may be more effective than either type of exercise alone in improving glycemic control and reducing the risk of developing type 2 diabetes 4, 5, 6.