Physician-authored summaries and commentary on the most important medical research, provided by the NEJM Group, a division of the Massachusetts Medical Society.
© Massachusetts Medical SocietyFebruary 2025
Among patients with insulin-treated diabetes, hypoglycaemia was common but usually asymptomatic.
Hypoglycaemic symptoms do not always correlate with hypoglycaemia documented by continuous glucose monitors (CGMs). To estimate the frequency of discordance between symptoms and CGM measurements, researchers recruited 600 people who used insulin to manage type 1 or 2 diabetes; participants wore CGMs and documented hypoglycaemic symptoms. Mean ages were 47 years for patients with type 1 diabetes and 63 years for patients with type 2 diabetes. Median glycosylated haemoglobin (HbA1c) was about 53 mmol/mol (7%), and about 25% of patients had poor hypoglycaemic awareness according to a standardised questionnaire.
Most patients (84%) had at least one episode of CGM-detected hypoglycaemia (glucose level below 3.0 mmol/L). Median weekly rates of CGM-detected hypoglycaemia were 1.3 episodes for patients with type 1 diabetes and 0.3 episodes for patients with type 2 diabetes. Nearly two-thirds of hypoglycaemia episodes were asymptomatic. Only 57% of patient-reported episodes of hypoglycaemia corresponded to low glucose measurements on CGMs.
Comment: The degree of mismatch between measured hypoglycaemia and symptoms of hypoglycaemia was surprising. About 25% of patients had poor hypoglycaemic awareness, which might explain the frequent asymptomatic hypoglycaemia. Although more research on the clinical significance of asymptomatic mild hypoglycaemia and symptomatic normoglycaemia would be welcome, this study is a good reminder that asymptomatic hypoglycaemia is common among patients who use insulin and likely signals a need to adjust the insulin regimen. Guidelines support use of CGMs to better identify and respond to hypoglycaemia in patients with insulin-treated diabetes (NEJM JW Gen Med Nov 1 2023 and Diabetes Care 2023; 46: e151-e199).
Christopher W. Goodman, MD, Clinical Assistant Professor of Internal Medicine, University of South Carolina School of Medicine, Columbia, USA.
Divilly P, et al. Relationship between sensor-detected hypoglycemia and patient-reported hypoglycemia in people with type 1 and insulin-treated type 2 diabetes: the Hypo-METRICS study. Diabetes Care 2024; 47: 1769-1777.
This summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine.