Why diabetes is linked to cognitive impairment in older adults

January, 2012
  • The link between diabetes and cognitive impairment in older adults seems to be mediated by the release of molecules that increase inflammation, leading to constricted blood vessels, thus reduced blood flow, and finally loss of gray matter.

Why is diabetes associated with cognitive impairment and even dementia in older adults? New research pinpoints two molecules that trigger a cascade of events that end in poor blood flow and brain atrophy.

The study involved 147 older adults (average age 65), of whom 71 had type 2 diabetes and had been taking medication to manage it for at least five years. Brain scans showed that the diabetic patients had greater blood vessel constriction than the age- and sex-matched controls, and more brain atrophy. The reduction in brain tissue was most marked in the grey matter in the parietal and occipital lobes and cerebellum. Research has found that, at this age, while the average brain shrinks by about 1% annually, a diabetic brain might shrink by as much as 15%. Diabetics also had more white matter hyperintensities in the temporal, parietal and occipital lobes.

Behaviorally, the diabetics also had greater depression, slower walking, and executive dysfunction.

The reduced performance of blood vessels (greater vasoconstriction, blunted vasodilatation), and increased brain atrophy in the frontal, temporal, and parietal lobes, was associated with two adhesion molecules – sVCAM and sICAM. White matter hyperintensities were not associated with the adhesion molecules, inflammatory markers, or blood vessel changes.

It seems that the release of these molecules, probably brought about by chronic hyperglycemia and insulin resistance, produces chronic inflammation, which in turn brings about constricted blood vessels, reduced blood flow, and finally loss of neurons. The blood vessel constriction and the brain atrophy were also linked to higher glucose levels.

The findings suggest that these adhesion molecules provide two biomarkers of vascular health that could enable clinicians to recognize impending brain damage, that could then perhaps be prevented.

The findings also add weight to the growing evidence that diabetes management is crucial in preventing cognitive decline.

Reference: 

Related News

A small UK study involving 28 healthy older adults (20 women with average age 70; 8 men with average age 67), has found that those with higher levels of aerobic fitness experienced fewer language failures such as 'tip-of-the-tongue' states.

Findings from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) Study, which followed 2,802 healthy older adults for 10 years, has found that those who participated in computer training designed to improve processing speed and visual attention had a 29% lower risk of dev

An Australian study involving 102 older adults (60-90) has concluded that physical fitness and arterial stiffness account for a great deal of age-related memory decline.

A long-running study involving 454 older adults who were given physical exams and cognitive tests every year for 20 years has found that those who moved more than average maintained more of their cognitive skills than people who were less active than average, even if they have brain lesions or b

Data from the English Longitudinal Study of Aging, in which nearly 4,000 older adults (60+) had their walking speed assessed on two occasions in 2002-2003 and in 2004-2005, those with a slower walking speed were more likely to develop dementia in the next 10 years.

Exercise activates brain networks in older adults

A study involving healthy older adults (55-85) found that recall was better after a session of moderately intense exercise, and several crucial brain regions showed greater activation.

Lowering blood pressure prevents worsening brain damage in elderly

A study involving 54 older adults (55-80), who possessed at least one risk factor for a stroke, found that those with

Perivascular spaces are fluid-filled spaces around the cerebral small vessels, commonly seen on brain scans in older adults. They have been thought to be harmless, but a new study challenges this belief.

Data from 3,105 older adults (65+) who had either heart surgery or cardiac catheterization has found that those who had heart surgery didn’t experience much greater cognitive decline compared with those who had the much less invasive, catheter-based procedure.

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health newsSubscribe to Latest news