Hypoglycemia and Cognitive Decline: Which Comes First?
Thomas L. Schwenk, MD reviewing Yaffe K et al. JAMA Intern Med 2013 Jun 10.
Each increases risk for developing the other.
In older adults with diabetes, a comorbid association exists between hypoglycemia and cognitive decline, but their temporal relation is less clear. Researchers evaluated the bidirectional nature of the association in retrospective data from a U.S. multisite health and aging study.
Frequency of hypoglycemic episodes and development of dementia were assessed in 783 older adults (mean age, 74) with diabetes and normal cognitive function at study entry. During 12 years of follow-up, 61 participants (8%) reported at least one hypoglycemic episode severe enough to require hospitalization, and 148 participants (19%) developed dementia. In analyses adjusted for many demographic and cardiovascular factors, participants who experienced severe hypoglycemic episodes were roughly twice as likely to subsequently develop dementia (crude incidence, 34% vs. 18%). Similarly, those who were diagnosed with dementia were about three times more likely to experience subsequent hypoglycemic episodes resulting in hospitalization (14% vs. 6%).
That each of these conditions might increase risk for the other, especially in older adults, is biologically plausible. These findings emphasize the importance of looking more aggressively for both of these conditions, which probably are underdiagnosed in many patients. They also provide further reason to set less-stringent glycemic targets in older adults, and to select treatment regimens with less risk for inadvertent hypoglycemia.
Yaffe K et al. Association between hypoglycemia and dementia in a biracial cohort of older adults with diabetes mellitus. JAMA Intern Med 2013 Jun 10; [e-pub ahead of print]. [PubMed ® abstract]
NEJM Journal Watch is produced by NEJM Group, a division of the Massachusetts Medical Society.
Copyright ©2013 Massachusetts Medical Society. All rights reserved.