Seven new genetic regions linked to type 2 diabetes

A study involving 65 older adults (average age 66), of whom 35 had type 2 diabetes, has found that after two years, those with diabetes had decreases in their ability to regulate blood flow in the brain, and a reduced ability to regulate blood flow was associated with lower cognitive scores.

Specifically, at the start of the study those with diabetes scored an average 46 points on a cognitive test, compared with 55 in the control group. After two years, the diabetics' scores had fallen to an average of 41, while the scores of the control group hadn't fallen at all.

A German study involving 1,936 older adults (50+) has found that mild cognitive impairment (MCI) occurred twice as often in those diagnosed with type 2 diabetes.

I’ve reported before on the growing evidence that metabolic syndrome in middle and old age is linked to greater risk of cognitive impairment in old age and faster decline. A new study shows at least part of the reason.

Damage to the retina (retinopathy) doesn’t produce noticeable symptoms in the early stages, but a new study indicates it may be a symptom of more widespread damage. In the ten-year study, involving 511 older women (average age 69), 7.6% (39) were found to have retinopathy. These women tended to have lower cognitive performance, and brain scans revealed that they had more areas of small vascular damage within the brain — 47% more overall, and 68% more in the parietal lobe specifically. They also had more white matter damage. They did not have any more brain atrophy.

Older adults who sleep poorly react to stress with increased inflammation

A study involving 83 older adults (average age 61) has found that poor sleepers reacted to a stressful situation with a significantly greater inflammatory response than good sleepers. High levels of inflammation increase the risk of several disorders, including cardiovascular disease and diabetes, and have been implicated in Alzheimer’s.

A study involving 130 HIV-positive people has found that memory impairment was associated with a significantly larger waistline.

Some 40% of participants (average age 46) had impaired cognition. This group had an average waist circumference of 39 inches, compared to 35 inches for those without such problems. Memory impairment was also linked to diabetes in those older than 55 (15% of those with memory problems had diabetes compared to only 3% of those without memory problems).

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.

In the last five years, three studies have linked lower neighborhood socioeconomic status to lower cognitive function in older adults. Neighborhood has also been linked to self-rated health, cardiovascular disease, and mortality. Such links between health and neighborhood may come about through exposure to pollutants or other environmental stressors, access to alcohol and cigarettes, barriers to physical activity, reduced social support, and reduced access to good health and social services.

Following several recent studies pointing to the negative effect of air pollution on children’s cognitive performance (see this April 2010 news report and this May 2011 report), a study of public schools in Michigan has found that 62.5% of the 3660 schools in the state are located in areas with high levels of industrial pollution, and those in areas with the highest industrial air pollution levels had the lo

Growing evidence links obesity and poorer cognitive performance. Many factors associated with obesity, such as high blood pressure, type 2 diabetes and sleep apnea, damage the brain.