Impaired Awareness of Hypoglycemia in Older Adults With Type 1 Diabetes: A Post Hoc Analysis of the WISDM Study

OBJECTIVE Up to one-third of older adults with type 1 diabetes experience impaired awareness of hypoglycemia (IAH), yet the factors associated with IAH remain underexplored in older adults. RESEARCH DESIGN AND METHODS This post hoc analysis evaluated the clinical and glycemic correlates of IAH in adults >= 60 years old with type 1 diabetes in the WISDM study. IAH and normal awareness of hypoglycemia (NAH) were defined by a Clarke score of >= 4 or <4, respectively. Demographic, clinical, and glycemic metrics were compared in those with IAH and NAH at baseline and in whom IAH did or did not improve over 26 weeks, using descriptive statistics and a multiple logistic regression variable selection procedure. RESULTS Of the 199 participants (age 68.1 +/- 5.7 years, 52% female), 30.6% had IAH. At baseline, participants with IAH had a longer diabetes duration and greater daytime hypoglycemia and glycemic variability, and more participants had nondetectable C-peptide levels than those with NAH. Logistic regression associated longer diabetes duration (odds ratio [OR] 1.03, 95% CI 1.01-1.05; P = 0.008) and greater daytime hypoglycemia (OR 1.31, 95% CI, 1.15-1.51; P < 0.0001) with a greater odds of IAH. A similar modeling procedure identified less daytime hypoglycemia (OR per additional percentage point 0.55, 95% CI 0.32-0.94; P = 0.029) and shorter diabetes duration (OR per additional year 0.96, 95% CI 0.91-1.004; P = 0.07) as predictors of restored awareness at 26 weeks, although the effect size for diabetes duration was not statistically significant. CONCLUSIONS In older adults with type 1 diabetes, longer diabetes duration and greater daytime hypoglycemia are drivers of IAH. Dedicated research can personalize IAH management.