Cognitive decline can accelerate, making patients especially vulnerable to mental impairment and dementia as they age.
Patients with diabetes face a number of challenges as they work with their physicians to manage their disease—adopting healthy lifestyles, finding the best treatment regimens, and dealing with comorbidities and drug-related adverse effects. And while modern medicine is prolonging the lives of these patients, it is becoming apparent that these individuals face additional mental challenges as they age. Diabetes can accelerate age-related cognitive decline, making patients especially vulnerable to impairment and dementia over time.
Katherine Samaras, MBBS, PhD, FRACP, who is Head of the Diabetes and Obesity Clinical Group at the Garvan Institute of Medical Research, in Sydney, Australia stated that, “We tend not to routinely consider cognitive decline in our patients with diabetes, though the older our patients are, the greater the risk is.”
A number of scientific facts have determined that diabetes detrimentally affects brain structure and function. Its effects on cognition are due at least in part to macrovascular disease, microvascular changes, hyperlipidemia, alterations in insulin homeostasis, and inflammation. Also, the relationship between hypoglycemia and dementia may be bidirectional. And we also know that patients with diabetes and cognitive impairment may be able to continue with self-care but might benefit from receiving additional ‘one-to-one’ support services, written instructions, or visual supports. Medication regimens might also need to be simplified to minimize medication-related risks.
A known fact is that diabetes is thought to account for 6% to 8% of all cases of dementia. The other side of the coin is that self-reported history of severe hypoglycemia has been linked with poorer late-life cognitive ability in people with type 2 diabetes.
Many other diabetes-related conditions are also likely to play a role in cognitive decline. For example, results from a recent sibling study of cardiovascular disease in individuals with a high prevalence of type 2 diabetes show that additional cardiovascular factors—especially calcified plaque and vascular status—and not diabetes status alone are major contributors to diabetes-related cognitive decline.
Cognitive impairment or decline can be dangerous in any situation, but it is especially worrisome in patients with diabetes. Their health relies on informed and independent self-care to achieve glycemic targets and minimize vascular risks. Unfortunately, annual screenings performed in patients with diabetes do not include an evaluation of cognition. “Clinicians can identify cognitive decline by performing a standard mini-mental state exam as part of annual screenings,” said Dr. Samaras. “This is very quick and simple, requires no tools, and has no cost. It can help identify patients at risk where a downward trend is noted,” she explained. “Our suspicion of declining cognitive function might also be raised by medication errors and confusion about performing some of the complex tasks of diabetes self-care, where none have been apparent previously.”
When cognitive problems are detected in patients with diabetes, it is often unclear how to intervene. Some patients may be able to continue with self-care but will benefit from receiving additional “one-to-one” support services, written instructions, or visual aids. Medication regimens might also need to be simplified to minimize medication-related risks.
In the Action to Control Cardiovascular Risk in Diabetes—Memory in Diabetes (ACCORD-MIND) randomized trial, intensive therapy to maintain glycemic control was associated with greater total brain volume after 40 months, but there was no improvement in cognition.
More research is warranted to determine whether diabetes’ negative effects on brain structure and function are explained by direct toxic effects of glucose or are mediated by other metabolic, lipid, or inflammatory alterations. “Additional longitudinal studies are needed that track cognitive changes over time in healthy elderly populations,” says Dr. Samaras.
The researchers added in a statement that, until more is known about the causes of diabetes-related cognitive decline and how to treat it, clinicians involved in the care of people with diabetes must do their very best to detect it and to make appropriate treatment changes that will safeguard their patients’ health. This is one more complication from diabetes that most likely can be prevented by controlling blood sugars.
- Diabetes can accelerate age-related cognitive decline.
- Diabetes detrimentally affects brain structure and function.
- Cognitive decline is especially worrisome in patients with diabetes.