Risk of Hypoglycemia in Older Veterans with Dementia and Cognitive Impairment: Implications for Practice and Policy

Abstract

OBJECTIVES: To examine the relationship between management of diabetes mellitus and hypoglycemia in older adults with and without dementia and cognitive impairment. DESIGN: Cross-sectional database analysis of veterans aged 65 years and older stratified according to dementia, cognitive impairment, age, antiglycemic medications, and glycosylated hemoglobin (Hba1c) level. SETTING: Research database with linked clinical, laboratory, pharmacy, and International Classification of Diseases, Ninth Revision, Clinical Modification, codes. PARTICIPANTS: Four hundred ninety-seven thousand nine hundred veterans aged 65 and older with diabetes mellitus who obtained services from the Department of Veterans Affairs in fiscal years (FYs) 2002 and 2003. MEASUREMENTS: Hypoglycemia, the outcome variable, was identified from outpatient visits, emergency department and inpatient admission codes in FY2003. Independent variables (FY2002-03) included dementia and cognitive impairment, comorbid conditions, extended care and nursing home stays, demographics, antiglycemic medication, and HbA1c levels. RESULTS: Prevalence of combined dementia and cognitive impairment was 13.1% for individuals aged 65 to 74 and 24.2% for those aged 75 and older. Mean HbA1c levels were 7.0 ± 1.3% for all participants and 6.9 ± 1.3% for those with dementia. The proportion of participants taking insulin was higher in those with dementia or cognitive impairment (30%) than in those with neither condition (24%). Of all participants taking insulin, more with dementia (26.5%) and cognitive impairment (19.5%) were hypoglycemic than of those with neither condition (14.4%). For all participants, unadjusted odds ratios (ORs) for hypoglycemia were 2.42 (95% confidence interval (CI) = 2.36-2.48) for dementia and 1.72 (95% CI = 1.65-1.79) for cognitive impairment; adjusted ORs were 1.58 (95% CI = 1.53-1.62) for dementia and 1.13 (95% CI = 1.08-1.18) for cognitive impairment. CONCLUSION: Diabetes mellitus was managed more intensively in older veterans with dementia and cognitive impairment, and dementia and cognitive impairment were independently associated with greater risk of hypoglycemia.