It is often assumed that people with poorly controlled Type 2 diabetes are not at risk for severe hypoglycemia (low blood glucose), given that their blood glucose levels tend to be high, on average. But according to new research conducted by Kaiser Permanente and the Yale School of Medicine, those who take certain types of diabetes medicines are at risk of dangerous lows whether or not their condition is well controlled.
Hypoglycemia, which may cause symptoms such as shakiness, dizziness, confusion, and sweating, can usually be treated by consuming a fast-acting carbohydrate such as glucose gel or juice. In cases of severe hypoglycemia, however, blood glucose levels drop so low that a person needs assistance to recover, and in extreme cases, hypoglycemia can lead to coma or even death. Medicines including insulin, sulfonylureas (chlorpropamide, glyburide, glipizide, glimepiride, tolbutamide, tolazamide), and meglitinides (nateglinide, repaglinide) all have the potential to cause hypoglycemia.
To determine the association between A1C level (an indicator of glucose control over the previous 2–3 months) and a person’s risk of severe hypoglycemia, researchers surveyed over 9,000 people with Type 2 diabetes who were being treated with glucose-lowering medicines. Participants were placed into one of five A1C categories, ranging from lowest to highest, and asked how many times they had experienced severe hypoglycemia requiring assistance in the previous year.
The researchers found that almost 11% of the respondents had experienced severe hypoglycemia in the previous 12 months and that it had occurred across the entire spectrum of diabetes control. People with the lowest and the highest A1C levels tended to have a higher risk for severe hypoglycemia compared to people with A1C levels in the middle range, but the differences were small and hypoglycemia was common across all five groups. “Poor control is certainly not protective,” the researchers noted.
According to senior study author Andrew Karter, PhD, “Many clinicians may assume that hypoglycemia is not much of a problem in poorly controlled Type 2 diabetes given their high average blood sugar levels. This study suggests that we should pay much closer attention to hypoglycemia, even in poorly controlled patients. Providers should explain the symptoms of hypoglycemia, how to treat it, and how to avoid it — for example, by not skipping meals. Most of all, providers should ask all their diabetic patients whether they’ve experienced hypoglycemia, even those patients with very high average levels of blood sugar.”
The researchers also recommended that evaluations of the quality of diabetes care take into account side effects such as hypoglycemia that are associated with treatment. “While aggressive treatment of high blood sugar was once considered a hallmark of better care, recent clinical trials have raised concerns about the risks of tight control, particularly in the frail and elderly,” Karter stated.
For more information, read the article “Severe Low Blood Sugar Occurs Often in Patients With Type 2 Diabetes” or see the study’s abstract in the journal Diabetes Care. And to learn more cutting down on low blood glucose, read the article “Take a Bite Out of Hypoglycemia,” by certified diabetes educator Gary Scheiner.