JAMA Netw Open

Maintaining blood sugar levels may reduce dementia risk

August 8, 2024

Older adults with diabetes who maintained stable blood sugar levels within personalized target ranges had a reduced risk of Alzheimer's disease and related dementias (ADRD). These findings, published in JAMA Network Open, suggest that lower HbA1c TIR may help identify individuals at increased risk of ADRD.

The study

• Researchers analyzed data from the Veterans Health Administration and Medicare to explore the association between HbA1C TIR and incidence of ADRD in veterans ≥65 years with diabetes (n=374,021; mean age, 73.2 years; 99% male).
• Participants had ≥4 HbA1c tests during the 3-year baseline period. HbA1C TIR was calculated as the percentage of days during baseline in which HbA1c was in individualized target ranges based on clinical characteristics and life expectancy, with higher HbA1c TIR viewed as more favorable. Investigators created 4 categories of HbA1c time in and out of range (ie, HbA1c TIR of ≥60%; time below range [TBR] of ≥60%; time above range [TAR] of ≥60%; and a mixed group [above or below target ranges most of the time]) and estimated the association with incident ADRD.

Key findings

• Adults who spent <20% of time in their HbA1c range during the outcome period had a higher risk for ADRD than those who spent ≥80% of time in their HbA1c target range (adjusted hazard ratio [aHR], 1.19; 95% CI, 1.16-1.23).
• Adults who spent ≥60% of their time below their HbA1c target range also had a higher risk for ADRD than those who spent ≥60% of their time in HbA1c range (aHR, 1.23; 95% CI, 1.16-1.27). No difference in risk was observed for adults with a time above HbA1c range of ≥60% and those with a time in HbA1c range of ≥60%.
• Findings remained significant after excluding individuals with baseline use of medications associated with hypoglycemia risk (ie, insulin and sulfonylureas) or with hypoglycemia events.

Source:

Underwood PC, et al. (2024, August 1). JAMA Netw Open. Glycated Hemoglobin A1c Time in Range and Dementia in Older Adults With Diabetes. https://pubmed.ncbi.nlm.nih.gov/39093563/