Type of insulin may affect hypoglycemia rates in older adults with type 2 diabetes, study finds

The risk of hospital visits for hypoglycemia was lower with long-acting insulin analogs versus neutral protamine Hagedorn (NPH) insulin in a retrospective study of Medicare patients.

Long-acting insulin analogs were associated with a lower risk of serious hypoglycemia than neutral protamine Hagedorn (NPH) insulin in patients ages 65 years or older with type 2 diabetes, a study found.

Researchers conducted a retrospective cohort study among Medicare beneficiaries who started insulin glargine (n=407,018), insulin detemir (n=141,588), or NPH insulin (n=26,402) from January 2007 to July 2019. The primary outcome was time to first ED visit or hospitalization for hypoglycemia. Results were published March 1 by JAMA Internal Medicine.

The study found 7,347 ED visits or hospitalizations for hypoglycemia, 5,194 among patients on insulin glargine, 1,693 for patients on insulin detemir, and 460 for NPH insulin. Insulin glargine and detemir were associated with a reduced risk for hypoglycemia compared with NPH insulin use (hazard ratios, 0.71 [95% CI, 0.63 to 0.80] for insulin glargine vs. NPH insulin and 0.72 [95% CI, 0.63 to 0.82] for detemir vs. NPH insulin). The decrease in hypoglycemia visits with long-acting insulin analogs varied by age, being strongest between the ages of 69 to 87 years. There was no significant difference in hypoglycemia by insulin type among patients who used prandial insulin.

“The inclusion of prandial insulin in type 2 diabetes treatment regimens may increase complexity, especially for older users, thereby increasing the possibility of using too much insulin, which might increase the likelihood of hypoglycemia to such an extent that the benefits from long-acting analogs compared with NPH insulin are lost,” the study authors noted. Limitations of the study include possible confounding due to its observational design.

An accompanying editorial noted that previous meta-analyses of randomized clinical trials have not found such differences between long-acting basal insulin analogs compared with insulin isophane suspension. The differences might be due to the age of patients in the studies or cost factors determining insulin choice in nonrandomized research, the editorial said.

The findings of this study do “suggest a need for caution for the use of insulin isophane suspension among Medicare beneficiaries, particularly those who may be at greatest risk for hypoglycemia,” the editorialists wrote. However, it's important to remember that basal insulin treatment choice is only one tool to reduce hypoglycemia among older adults, they noted.