From the Guidelines
An HbA1c level above 10% carries a high risk of diabetic ketoacidosis (DKA). This elevated level indicates poor glycemic control over the previous 2-3 months, with average blood glucose levels exceeding 240 mg/dL. When blood glucose remains consistently high, the body cannot properly use glucose for energy and begins breaking down fat for fuel instead, producing ketones as a byproduct. As ketones accumulate in the bloodstream, they make the blood acidic, leading to ketoacidosis. Patients with type 1 diabetes are particularly vulnerable to DKA, though it can occur in type 2 diabetes during severe illness or stress.
Key Points to Consider
- Warning signs of impending ketoacidosis include excessive thirst, frequent urination, nausea, vomiting, abdominal pain, fruity-scented breath, confusion, and fatigue.
- Regular blood glucose monitoring, adherence to insulin therapy, and periodic ketone testing when glucose levels exceed 240 mg/dL are essential preventive measures for those with high HbA1c levels.
- The American Diabetes Association recommends considering starting insulin therapy when HbA1c levels are 10% to 12%, especially if symptomatic or catabolic features are present 1.
- Recent evidence from cardiovascular outcomes trials has shown that certain medications, such as empagliflozin and liraglutide, may reduce the risk of major cardiovascular events in patients with type 2 diabetes and established cardiovascular disease 1.
- However, the U.S. Food and Drug Administration has issued a warning that SGLT-2 inhibitors may lead to ketoacidosis in the absence of significant hyperglycemia, termed “euglycemic diabetic ketoacidosis” 1.
From the Research
HbA1c Levels and Risk of Ketoacidosis
- The risk of ketoacidosis is associated with high HbA1c levels, although the exact threshold is not clearly defined in the provided studies 2, 3, 4, 5, 6.
- A study published in the Journal of Diabetes suggests that HbA1c levels exceeding 9.0% and 10% are associated with a high risk of ketoacidosis, particularly in symptomatic patients 2.
- Another study published in Diabetic Medicine found that patients with HbA1c levels ≥ 58 mmol/mol (≥ 7.5%) had a higher risk of ketoacidosis, and that switching from once-daily to twice-daily basal insulin reduced the risk of ketoacidosis by 63% 3.
- The American Diabetes Association recommends using HbA1c as a diagnostic criterion for diabetes, with levels ≥ 48 mmol/mol (≥ 6.5%) indicating diabetes 5, 6.
- A cohort study published in BMC Medicine found that HbA1c levels ≥ 44 mmol/mol (≥ 6.2%) were associated with a higher risk of developing type 2 diabetes, with a 5-year risk of 26.4% 6.
Implications for Diabetes Management
- The choice of HbA1c threshold for identifying individuals at high risk of type 2 diabetes and ketoacidosis has implications for diabetes prevention programs and treatment strategies 6.
- Increasing the HbA1c threshold for identifying high-risk individuals may reduce the number of people classified as high-risk, but may also miss cases of diabetes and ketoacidosis 6.
- Further research is needed to determine the optimal HbA1c threshold for identifying individuals at high risk of ketoacidosis and to develop effective prevention and treatment strategies 2, 3, 4, 5, 6.