Sulfonylureas – association with low blood sugar in treatment of type 2 diabetes

This study aimed to compare the risk of low blood sugar associated with sulfonylureas (a class of drugs), in comparison with other drug types in type 2 diabetes. 

Sulfonylureas work by increasing insulin production by the pancreas, lowering blood glucose.  Examples include glimepiride (Amaryl), glipizide (GlipiZIDE XL, Glucotrol, Glucotrol XL) and glyburide (DiaBeta, Glynase PresTab, Micronase).

Hypoglycemia (dangerously low levels of glucose) is one of the most frequent negative side effects of diabetes treatments. Sulfonylureas have previously been associated with a greater risk of hypoglycemia than other drug types.

This study aimed to compare sulfonylureas with other drug types, in relation to the associated risk of hypoglycemia.

Results from over 60 studies with a total of over 40,000 participants were analyzed. The occurrence of hypoglycemia  was compared between patients treated with sulfonylureas and patients treated with other drug types or a placebo (a substance that has no therapeutic effect, used for control in testing new drugs). Patient characteristics such as body mass index (BMI, a measure of body fat that takes height and weight into account) and HbA1c (average blood glucose over 3 months) were examined.  

17.4%  of patients treated with sulfonylureas experienced hypoglycemia at least once during treatment. This risk was 3.69 times higher than it was for patients treated with other drugs or placebo.

The rate of severe hypoglycemia (resulting in unconsciousness or seizure) in patients treated with sulfonylureas was 1.2%. This was over three times higher than the risk of severe hypoglycemia in patients being treated with other drugs or a placebo.

Patients with a higher body mass index and a lower HbA1c before the study were at a higher risk of developing hypoglycemia.

The authors of this study concluded that treatment with sulfonylureas is associated with a higher risk of hypoglycemia than treatment with other drug types.  Patients with a higher BMI and a lower HbA1c level before treatment could be at a higher risk.

Further studies are required to identify indicators of risk for hypoglycemia in patients taking sulfonylureas.

Consult your doctor if you are taking a sulfonylurea drug and you are concerned about your risk of low blood sugar, especially if you have a high BMI and/or low HbA1c.