Introduction

Older adults may experience a decrease in their ability to think clearly, plan, and organize for several reasons - increased age, lack of education, and physical changes, such as stroke or Parkinson's disease. However, this study showed that elderly with diabetes mellitus might be at risk for additional declines in mental functioning, which in turn could affect their day-to-day functioning, including the self-care that is needed to manage diabetes successfully. These findings point to the importance of routine mental status screening of older adults with diabetes. With regular screening and early detection of changes in a person's thinking and level of awareness, treatment can be tailored to better fit his or her needs, and thereby reduce the chances of developing complications due to inadequate self-care.

Researchers in Wales compared the mental status of 396 patients with diabetes mellitus with a similar group of 393 patients without diabetes. All patients were age 65 years or older, with most in their mid-70s. All were retired from paid work, and came from both the city and rural areas. Most were white, which reflects the general ethnicity of Wales. The majority of the diabetes patients (82%) managed their disease by changing their eating habits or by taking oral medication in addition to adjusting their diet. The remaining participants used both dietary changes and insulin to manage the disease.

Participants were evaluated to determine their awareness of time and place, attention, memory, language construction, planning, and organizational ability. (These abilities are sometimes collectively called "cognitive" functioning.)

Factors related to declines in thinking and planning

Researchers found that overall thinking ability declined somewhat in older adults regardless of whether they had diabetes or not. The lower mental status was associated with getting older and having less clear vision. Participants who had less education and who had worked primarily in manual labor jobs prior to retirement had greater losses in ability to think and plan. In contrast, individuals who completed high school, had some college, or worked in professional or skilled jobs showed fewer cognitive declines after age 65.

Many older adults with diabetes had deficits as pronounced as those seen in people with moderate to severe dementia. More complicated treatment regimens, such as taking insulin, were only loosely related to a decline in mental status. Contrary to what they expected, researchers in this study found no connection between impairment in the ability to reason and the length of time an older adult had diabetes. But overall, diabetes showed a significant influence on patients' ability to think clearly and plan, even after taking age and vision into account.

Older adults with lower mental status scores due to diabetes were more likely:

• to have been hospitalized in the previous year
• to require help with self care
• to be living in an institution
• to have significantly lower scores when tested on activities of daily living

They were less likely:

• to be the person primarily responsible for the management of their diabetes
• to attend a specialty clinic for diabetes

Which comes first - poor self-care that leads to changes in brain function? Or is it the other way around? Researchers in this study believed it is more likely that brain deterioration from diabetes leads to changes in elderly adults' ability to think clearly and plan, and to self-manage the disease.

Importance of screening and early detection

One of the most important conclusions of this study is that older adults with diabetes should be routinely screened for changes in brain function. This mental status screening should start when diabetes is first diagnosed, then repeated at least every 3 years. Mental status screening should also be done if the individual shows a noticeable decline in everyday functioning, (such as confusion about the dates, or forgetting to buy food for upcoming meals).

Why is early detection important? First, further complications caused by declines in brain function can be reduced. Problems with thinking and planning may change how the diabetes needs to be treated. Early detection gives the opportunity to match treatment with the individual's needs. If health care providers know about the older adult's changes in awareness and thinking, treatment might be tailored to make it easier for the individual to live with diabetes. For example, more in-home care or "meals on wheels" might be arranged to help patients maintain special diets. New drug treatments might be started earlier. Also, medication instructions can be reviewed for ease of patient understanding, and adjustments made if the elderly person requires simplified or more structured instructions (e.g. the use of timers as a reminder to take medication).

Early detection also provides an opportunity to address legal, financial, and end-of-life decisions while the individual has the awareness to plan and make these types of choices.

Comment

While there have been several prior studies to show a link between Type 2 diabetes and poor cognitive performance¹, ², this study made a stride forward by sorting through the many factors that may also contribute to problems in thinking and planning. As a result, the researchers identified the most salient risk factors and made recommendations for screening to increase early detection. This study also showed the importance of evaluating older diabetics' ability to take care of themselves - even if they are diagnosed with non-insulin dependent Type 2 diabetes. This is because cognitive declines might affect not only the ability to manage oral medications, but also the lifestyle aspects of disease management (such as proper eating and adequate exercise). It may also be important to educate caregivers and family members of older adults with diabetes to look more closely at changes in day-to-day functioning.

Another important finding of this study is that the people who most need to be in specialty clinics are the least likely to attend. Routine screening for changes in brain functioning would allow patients to be referred for specialty care and appropriate follow up, which could in turn, help reduce or slow down further complications of the disease.

Participants in the study described above were from Wales, so were predominantly white. Although the changes in cognitive functioning shown here seem related to the disease itself, further research would be helpful to find out if these changes are similar among other nationalities and ethnic groups.

Researchers acknowledged two specific factors that may influence self-management of diabetes that were not considered in this study - use of drugs that affect the central nervous system, and unrecognized depression. Both can cause some degree of change in thinking, awareness, and planning.

Despite some limitations, this study is compelling in bringing to attention the need for routine screening of diabetic elderly for changes in brain function. Patients and their families can start now by watching for changes in day-to-day functioning, asking providers to do baseline testing of mental status, and seeking out specialty clinics to be sure current treatments are tailored to the individual's needs. By being proactive, patients and family can stay smart about diabetes.