‘Relaxed’ A1c OK for Mitigating Dementia Risk in Older Diabetes Patients

Even hitting more lenient glycemic targets was enough to keep dementia risk at bay in older adults with type 2 diabetes, researchers assured.

Based on over a quarter of a million patients, those who kept more than half of their hemoglobin A1c (HbA1c) measures under 9% saw a significantly lower risk for dementia compared with those who had the majority of measurements over this threshold, reported Chris Moran, PhD, of Monash University and the National Centre for Healthy Ageing in Melbourne, Australia, and colleagues.

More specifically, patients who had more than half of HbA1c measures between 9% to just under 10% saw a 31% increased risk for dementia than those with less than half of their measures in this range (adjusted HR 1.31, 95% CI 1.15-1.51), the group wrote in JAMA Neurology.

Likewise, those who had more than half of their HbA1c readings over 10% had a 74% higher risk for dementia than those with less than half of their measures in this category (adjusted HR 1.74, 95% CI 1.62-1.86). The highest incidence of dementia occurred among those with 75% or more of their HbA1c readings of 10% or higher over the average 5.9-year-long follow-up period.

“Importantly, we observed no significant change in hazard for individuals with HbA1c concentrations in the range of relaxed glycemic control recommended by the American Geriatrics Society and U.S. Department of Veterans Affairs for older patients with multiple comorbidities, poor health, or limited life expectancy,” the researchers pointed out.

The American Geriatrics Society’s clinical guidelines recommend a target HbA1c goal between 7.5% and 8% for older adults or a higher target between 8% and 9% for those with multiple comorbidities, poor health, and limited life expectancy.

Ideal glycemic targets for older patients with diabetes has long been at the forefront of clinical discussion. While it’s important to avoid any harms that come from hyperglycemia, intensive glucose control can put this population at jeopardy for the harmful effects of hypoglycemia, like falls.

“The harm associated with intensive glucose control has led the American Diabetes Association, American Geriatrics Society, Endocrine Society, and U.S. Department of Veterans Affairs to recommend that glycemic targets for people in middle to later life be individualized and to consider risk of hypoglycemia, number and severity of comorbidities, functional independence, cognitive impairment, and life expectancy,” Moran’s group explained. “Each of these organizations differs with regard to the exact therapeutic target recommended and encourages this to be developed based on a person’s individual circumstances.”

Beyond that, older patients in the study who had more than half of their HbA1c readings below 8% saw a modest, but significantly lower risk for developing dementia:

• Less than 6%: adjusted HR 0.92 (95% CI 0.88-0.97)
• 6% to less than 7%: adjusted HR 0.79 (95% CI 0.77-0.81)
• 7% to less than 8%: adjusted HR 0.93 (95% CI 0.89-0.97)

Patients with type 2 diabetes ages 50 and older (average age 62) were included in the analysis. All were members of the Kaiser Permanente Northern California integrated health care system. Dementia was defined using ICD-9 codes.

Half of the patients were white, while 18% were Asian, 15% Hispanic, and 10% were Black. There were, on average, 11.6 HbA1c measurements per person during the course of follow-up among the cohort.