High HbA1c levels linked to increased dementia risk in adults with type 2 diabetes: 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.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.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