How High Plasma Glucose Impacts Risk of Unspecified Dementia

Observational and genetical analysis revealed high plasma glucose has a causal effect on risk of unspecified dementia, according to a study published online in Diabetologia. 

The study used a Mendelian randomization method to analyze data from 115,875 people from the Copenhagen General Population Study and the Copenhagen City Heart Study.  

Observational multifactorial-adjusted analyses revealed hazard ratios of 1.15 for unspecified dementia, 0.91 for Alzheimer disease, and 1.16 for vascular dementia in people with a glucose level higher than 7 mmol/l compared with 5–6 mmol/l, according to the study. Hazard ratios were 1.42 for unspecified dementia, 1.11 for Alzheimer disease, and 1.73 for vascular dementia in people with type 2 diabetes compared with people without type 2 diabetes. 

Meanwhile, genetic causal analyses showed a 1 mmol/l higher plasma glucose level had a relative risk of 2.40 for unspecified dementia, 1.41 for Alzheimer disease, and 1.20 for vascular dementia. 

When researchers validated their Alzheimer disease findings in a two-sample Mendelian design with 455,258 people, including 71,880 people with Alzheimer disease or a parent with Alzheimer disease, they found a relative risk of 1.03 for Alzheimer disease. 

“Observational and genetically high plasma glucose are causally related to the risk of unspecified dementia,” researchers concluded, “but not to Alzheimer disease or vascular dementia.” 

—Jolynn Tumolo

Reference:

Benn M, Nordestgaard BG, Tybjærg-Hansen A, Frikke-Schmidt R. Impact of glucose on risk of dementia: Mendelian randomisation studies in 115,875 individuals. Diabetologia. 2020;63(6):1151‐1161. doi:10.1007/s00125-020-05124-5