PHOENIX — Is serious hypoglycemia associated with progression of atherosclerosis in veterans?

An investigation published recently in the journal Diabetes Care sought to answer that question and came up with a mixed answer.1

Researchers from the Phoenix VA Health Care System and the Cooperative Studies Program Coordinating Center at the Hines, IL, VAMC, used a substudy of the Veterans Affairs Diabetes Trial (VADT) to determine whether a link exists and whether glycemic control during the VADT modified the association between serious hypoglycemia and coronary artery calcium (CAC) progression.

For the study, serious hypoglycemia was defined as severe episodes with loss of consciousness/requiring assistance or documented glucose of less than 50 mg/dL. Baseline and follow-up computed tomography scans were used to determine progression of CAC in 197 participants.

During an average follow-up of 4.5 years between scans, 97 participants reported severe hypoglycemia or glucose levels less than 50 mg/dL. Results indicate that serious hypoglycemia occurred more frequently in the intensive therapy group than in the standard treatment group — 74% vs. 21%.

Yet, study authors report that serious hypoglycemia was not associated with progression of CAC in the entire cohort, although the interaction between serious hypoglycemia and treatment was significant.

Results indicate that participants with serious hypoglycemia in the standard therapy group, but not those in the intensive therapy group, had about a 50% greater progression of CAC than those without serious hypoglycemia. That held true even after adjusting for baseline differences, including CAC, or time-varying risk factors during the trial.

When researchers examined the effect of serious hypoglycemia by on-trial HbA1c levels with a cutoff of 7.5%, similar results occurred. A dose-response relationship between serious hypoglycemia and CAC progression was found but only in the standard therapy group.

“Despite a higher frequency of serious hypoglycemia in the intensive therapy group, serious hypoglycemia was associated with progression of CAC in only the standard therapy group,” study authors conclude.

1 Saremi A, Bahn GD, Reaven PD; Veterans Affairs Diabetes Trial (VADT). A Link Between Hypoglycemia and Progression of Atherosclerosis in the Veterans Affairs Diabetes Trial (VADT). Diabetes Care. 2016 Jan 19. pii: dc152107. [Epub ahead of print] PubMed PMID: 26786575.