Diabetes is a risk factor for dementia. It is unknown whether higher glucose levels increase the risk of dementia in people without diabetes mellitus.
Researchers used 35,264 clinical measurements of glucose levels and 10,208 measurements of glycated hemoglobin levels from 2067 participants without dementia to examine the relationship between glucose levels and the risk of dementia.
Participants were from the Adult Changes in Thought study and included 839 men and 1228 women whose mean age at baseline was 76 years; 232 participants had diabetes mellitus, and 1835 did not.
During a median follow-up of 6.8 years, dementia developed in 524 participants ( 74 with diabetes mellitus and 450 without ).
Among participants without diabetes, higher average glucose levels within the preceding 5 years were related to an increased risk of dementia ( P=0.01 ); with a glucose level of 115 mg per deciliter ( 6.4 mmol per liter ) as compared with 100 mg per deciliter ( 5.5 mmol per liter ), the adjusted hazard ratio for dementia was 1.18.
Among participants with diabetes mellitus, higher average glucose levels were also related to an increased risk of dementia ( P=0.002 ); with a glucose level of 190 mg per deciliter ( 10.5 mmol per liter ) as compared with 160 mg per deciliter ( 8.9 mmol per liter ), the adjusted hazard ratio was 1.40. ( Xagena )
Crane PK et al, N Engl J Med 2013; 369:540-548