Hypoglycemia and the kidneys in type 2 diabetes

This study examined the association between hypoglycemia (dangerously low blood glucose [sugar]) and kidney function in type 2 diabetes.

High blood glucose levels can lead to nerve, blood vessel, and kidney damage in patients with type 2 diabetes. Controlling blood glucose levels is thought to reduce the risk of developing these complications. However, intense blood glucose control can increase the risk of hypoglycemia by up to 30%. Severe hypoglycemia (needing the help of another person) increases the risk of blood vessel damage and death. Therefore, it is important to understand the association between episodes of severe hypoglycemia and diabetic complications such as kidney damage.

Creatinine is a chemical substance produced by the muscles. Measuring serum creatinine (creatinine in blood samples) is a simple test and is the most commonly used indicator of kidney function. Generally a rise in blood creatinine level indicates that the kidneys are not functioning properly.

This study examined the records of 101 type 2 diabetes patients who experienced severe hypoglycemia. These patients were compared to 101 type 2 diabetes patients who did not experience hypoglycemia. Kidney function was measured by comparing blood creatinine levels and filtration rates (the speed at which the blood is filtered by the kidneys) from before (baseline), just after, and roughly one year after severe hypoglycemia (follow-up).

In patients who experienced severe hypoglycemia, average blood creatinine levels increased by 0.35 mg/dL just after the episode, and had increased by a further 0.17 mg/dL by the follow-up visit. Creatinine levels did not change in patients who did not experience severe hypoglycemia.

Filtration rates decreased by 3.09 ml/min/1.73 m² following severe hypoglycemia, and decreased another 3.64 ml/min/1.73 m² by the follow-up visit. These rates did not change in patients who did not experience severe hypoglycemia.

This study concluded that severe hypoglycemia is associated with a decline in kidney function in patients with type 2 diabetes.