Prediabetes tied to a faster cognitive decline among elderly: Study

Finland: A recent study in the journal Diabetes Research and Clinical Practice has pointed out that prediabetes is associated with cognitive decline during aging.

"Because there is an increased worldwide prevalence of both dementia and type 2 diabetes, this finding should be incorporated into prevention strategies," the researchers wrote. 

Dysglycemia is a broad term that refers to an abnormality in blood sugar stability that includes low blood sugar or high blood sugar.

A total of 88 million people are estimated to be prediabetic. Previous studies have shown pre-diabetes and diabetes to be associated with minor deficits in global cognitive function, processing speed, and executive functioning. Sanna Papunen, Centre for Life Course Health Research, Faculty of Medicine, University of Oulu, Finland, and colleagues aimed to evaluate associations between glucose metabolism and cognitive performance during a 12-year follow-up in a longitudinal study. 

The study included 714 subjects, which were followed from the age 55 to 70 years. Using oral glucose tolerance tests the population was classified as normoglycemic (NGT) and based on WHO diagnostic criteria for diabetes and prediabetes. Cognitive performance was assessed with a verbal fluency (category) test and wordlist learning tests of CERAD-nb, a verbal fluency (letter) test, and trail-making tests A and B.

The results of the study were found to be:

• Compared to the normal group subjects with long-lasting prediabetes showed a significantly greater decline (4.6 versus 2.9 words) on the verbal fluency (category) test.

• Subjects with long-lasting type 2 diabetes showed a significantly greater decline (13 versus 6 s) on the trail-making A test and on the wordlist learning test (3.3 versus 1.7 words).

• combined group of subjects with prediabetes or incident type 2 diabetes showed significantly greater cognitive decline (3.8 versus 2.9 words) in the verbal fluency (category) test.

Papunen and team concluded that "Prediabetes was associated with cognitive decline during aging. This finding should be incorporated into prevention strategies because both type 2 diabetes and dementia are increasing worldwide." Studies have been inconclusive, about prediabetes and cognition but these aren't to be overlooked in the future.

Reference:

The study titled, "Long-term dysglycemia as a risk factor for faster cognitive decline during aging: a 12–year follow-up study," is published in the journal Diabetes Research and Clinical Practice.

DOI: https://www.diabetesresearchclinicalpractice.com/article/S0168-8227(21)00404-6/fulltext