Looking after a spouse with dementia greatly increases your own risk of dementia

Type 2 diabetes is known to increase the risk of cognitive impairment in old age. Now analysis of data from 41 older diabetics (aged 55-81) and 458 matched controls in the Victoria Longitudinal Study has revealed that several other factors make it more likely that an older diabetic will develop cognitive impairment. These factors are: having higher (though still normal) blood pressure, having gait and balance problems, and/or reporting yourself to be in bad health regardless of actual problems.

I have often spoken of the mantra: What’s good for your heart is good for your brain. The links between cardiovascular risk factors and cognitive decline gets more confirmation in this latest finding that people whose hearts pumped less blood had smaller brains than those whose hearts pumped more blood. The study involved 1,504 participants of the decades-long Framingham Offspring Cohort who did not have a history of stroke, transient ischemic attack or dementia. Participants were 34 to 84 years old.

Data from a 35-year study of women from Gothenburg in Sweden has revealed that the risk of dementia was about 65% higher in women who reported repeated periods of stress in middle age than in those who did not. The risk increased with number of periods of stress, with women who reported stress on all three occasions they were asked (1968, 1974 and 1980) having more than double the risk of dementia. Stress was defined as a sense of irritation, tension, nervousness, anxiety, fear or sleeping problems lasting a month or more due to work, health, family or other problems.

Following on from indications that gum disease might be a risk factor for dementia, analysis of data from 152 subjects in the Danish Glostrop Aging Study has revealed that periodontal inflammation at age 70 was strongly associated with lower cognitive scores (on the Digit Symbol Test). Those with periodontal inflammation were nine times more likely to test in the lower range compared to those with little or no periodontal inflammation. A larger follow-up study, among a more ethnically diverse range of subjects, is planned. I hope they also plan to extend the cognitive testing.

A study involving over 180,000 older veterans (average age 68.8 at study start), of whom 29% had PTSD, has revealed that those with PTSD had a significantly greater risk of developing dementia. Over the seven years of the study, 10.6% of the veterans with PTSD developed dementia compared to 6.6% of those without PTSD. When age was used as the time scale, the risk for those with PTSD was more than double. Results were similar when those with a history of head injury, substance abuse, or clinical depression, were excluded.

Another study has come out showing that older adults with low levels of vitamin D are more likely to have cognitive problems. The six-year study followed 858 adults who were age 65 or older at the beginning of the study. Those who were severely deficient in vitamin D were 60% more likely to have substantial cognitive decline, and 31% more likely to have specific declines in executive function, although there was no association with attention.

Anticholinergics are widely used for a variety of common medical conditions including insomnia, allergies, or incontinence, and many are sold over the counter. Now a large six-year study of older African-Americans has found that taking one anticholinergic significantly increased an individual's risk of developing mild cognitive impairment and taking two of these drugs doubled this risk. The risk was greater for those who didn’t have the ‘Alzheimer’s gene’, APOE-e4.

A comprehensive study reveals how the ‘Alzheimer's gene’ (APOE ε4) affects the nature of the disease. It is not simply that those with the gene variant tend to be more impaired (in terms of both memory loss and brain damage) than those without. Different parts of the brain (and thus different functions) tend to be differentially affected, depending on whether the individual is a carrier of the gene or not. Carriers displayed significantly greater impairment on tests of memory retention, while noncarriers were more impaired on tests of working memory, executive control, and lexical access.

A study involving 733 participants from the Framingham Heart Study Offspring Cohort (average age 60) provides more evidence that excess abdominal fat places otherwise healthy, middle-aged people at greater risk for dementia later in life. The study also confirms that a higher BMI (body mass index) is associated with lower brain volumes in both older and middle-aged adults. However the association between visceral fat and total brain volume was independent of BMI. Visceral fat differs from subcutaneous fat in that it is buried deeper, beneath the muscles, around the organs.

Another gene has been identified that appears to increase risk of Alzheimer’s. The gene, MTHFD1L, is located on chromosome six. Comparison of the genomes of 2,269 people with late-onset Alzheimer's disease and 3,107 people without the disease found those with a particular variation in this gene were almost twice as likely to develop Alzheimer's disease as those people without the variation. The gene is involved in influencing the body's levels of homocysteine (high levels are known to be a strong risk factor), and have also been implicated in coronary artery disease.