High HbA1c levels may increase dementia risk in type 2 diabetes patients: JAMA

Australia: Dementia is a growing concern, especially in older populations. New research published in JAMA: Neurology suggests that adults with type 2 diabetes may have a higher risk of developing dementia if their HbA1c levels are 9% or higher.

Previous research has shown a strong association between type 2 diabetes and cognitive impairment, including dementia. The study aimed to identify the levels of glycemic control associated with the lowest risk of dementia, which is important for setting patient-centered glycemic targets. The study also included dementia risk across demographic factors such as sex, race, and ethnic groups along with the association of current therapeutic glycemic targets.

The cohort study included over 253,211 participants of the Kaiser Permanente Northern California integrated healthcare system with type 2 diabetes who were aged 50 years or older during the study period from January 1, 1996, to September 30, 2015.

Individuals with prevalent dementia at baseline, fewer than 2 HbA1c measurements during the study period, or less than 3 years of follow-up were excluded. More than half of the participants were men, and the mean follow-up duration was 5.9 years.

The study concluded with the following clinical findings:

1. 1.Participants with more than 50% of HbA1c measurements at 9% to less than 10% or 10% or more had a greater risk of dementia compared to those with fewer measurements in those categories.
2. 2.Participants with more than 50% of HbA1c concentrations less than 6%, 6% to less than 7%, or 7% to less than 8% had a lower risk of dementia.

The study also found that current therapeutic glycemic targets for older people with type 2 diabetes are appropriately relaxed. The results support current guidelines recommending a less stringent glycemic target for older adults with diabetes.

The study's lead author, Dr. Chris Moran, stated, "We found that moderate glycemic control is optimal for dementia prevention in people with type 2 diabetes. We hope these results can inform guidelines for individualized glycemic targets for older adults with diabetes, with an eye towards protecting cognitive health in addition to overall physical health."

Reference:

Moran C, Lacy ME, Whitmer RA, et al. Glycemic Control Over Multiple Decades and Dementia Risk in People with Type 2 Diabetes. JAMA Neurol. Published online April 17, 2023. doi:10.1001/jamaneurol.2023.0697