Elderly patients most likely to land in ED, get admitted for insulin-related hypoglycemia

Elderly patients are more likely than younger patients to land in the ED and be hospitalized for insulin-related hypoglycemia and errors, a new study found.

Researchers used data on insulin-related hypoglycemia and errors (IHE) from the 63 U.S. hospitals that participated in the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project. They also estimated the number of patients with diabetes who used insulin or oral medication from the National Health Interview Survey. Outcomes included annual numbers and annual rates of ED visits and hospitalizations for IHEs among insulin-treated patients with diabetes from January 2007 through December 2011. Results were published online March 10 by JAMA Internal Medicine.

An estimated 97,648 annual ED visits occurred for IHEs, 29% of which resulted in hospitalization. Patients who were at least 80 years old and treated with insulin were 2.5 times as likely to visit the ED (rate ratio [RR], 2.5; 95% CI, 1.5 to 4.3) and almost 5 times as likely to be hospitalized (RR, 4.9; 95% CI, 2.6 to 9.1) for IHEs as patients aged 45 to 64 years. The estimated median age of those who came to the ED for IHEs was 60 years for patients treated with insulin alone and 67 years for those treated with insulin and at least 1 oral antidiabetic medication. Indeed, across all age groups, patients who took only insulin were more likely than those taking insulin with oral glucose-lowering medications to have an ED visit.

In about 61% of the ED visits, severe neurologic sequelae were documented, such as hypoglycemia-associated shock, loss of consciousness or seizure. In 53% of ED visits, blood glucose levels of 50 mg/dL (2.8 mmol/L) or below were documented. Twenty-nine percent of ED visits for IHEs required admission, transfer to another facility, or observation. The most commonly reported precipitating factors for ED visits for IHEs were reduced food intake and having taken the wrong insulin product—often, having confused long- and short-acting products.

The risks of hypoglycemic sequelae in patients aged 80 years and older ought to be considered in decisions about prescribing and intensifying insulin, the authors wrote. An editorialist noted that, while occasional episodes are bound to occur, this study indicates insulin-related hypoglycemia is “far too common.” To reduce insulin-related hypoglycemia, the editorialist recommended specifically targeting an HbA1c of 6.5% to 7% (as opposed to under 7%), developing glycemic-overtreatment quality indicators, and avoiding insulin in most adults older than 80 years.