Obesity, metabolic factors linked to faster cognitive decline

People who are obese and also have high blood pressure and other risk factors called metabolic abnormalities may experience a faster decline in their cognitive skills over time than others, according to a study published in the August 21, 2012, print issue of Neurology, the medical journal of the American Academy of Neurology.

25 aug 2012--Metabolic abnormality was defined as having two or more of the following risk factors: high blood pressure or taking medication for it; low HDL or "good" cholesterol; high blood sugar or taking diabetes medication; and high triglycerides (a type of fat found in the blood) or taking medication to lower cholesterol.

The study involved 6,401 people with an average age 50 at the start of the study. Information on body mass index (BMI) and the risk factors was gathered at the beginning of the study. The participants took tests on memory and other cognitive skills three times over the next 10 years.

A total of 31 percent of the participants had two or more metabolic abnormalities. Nine percent were obese and 38 percent were overweight. Of the 582 obese people, 350, or 60 percent, met the criteria for metabolic abnormality. The metabolically normal obese individuals also experienced more rapid decline.

Over the 10 years of the study, people who were both obese and metabolically abnormal experienced a 22.5 percent faster decline on their cognitive test scores than those who were of normal weight without metabolic abnormalities.

"More research is needed to look at the effects of genetic factors and also to take into account how long people have been obese and how long they have had these metabolic risk factors and also to look at cognitive test scores spanning adulthood to give us a better understanding of the link between obesity and cognitive function, such as thinking, reasoning and memory," said study author Archana Singh-Manoux, PhD, of INSERM, the French research institute in Paris and University College London in England.

Singh-Manoux said the study also provides evidence against the concept of "metabolically healthy obesity" that has suggested that obese people without metabolic risk factors do not show negative cardiac and cognitive results compared to obese people with metabolic risk factors.

Provided by American Academy of Neurology

New research shows the trajectory of cognitive decline can be altered in seniors at risk for dementia

Cognitive decline is a pressing global health care issue. Worldwide, one case of dementia is detected every seven seconds. Mild cognitive impairment is a well recognized risk factor for dementia, and represents a critical window of opportunity for intervening and altering the trajectory of cognitive decline in seniors.
25 april 2012--A new study by researchers at the Centre for Hip Health and Mobility at Vancouver Coastal Health and the University of British Columbia shows that implementing a seniors' exercise program, specifically one using resistance-training, can alter the trajectory of decline. Perhaps most importantly, the program improved the executive cognitive process of selective attention and conflict resolution as well as associative memory, which are robust predictors of conversion from mild cognitive impairment to dementia.
The research led by Teresa Liu-Ambrose, principal investigator with the Centre for Hip Health and Mobility and the Brain Research Centre at VCH and UBC, and co-investigators from the Department of Psychology and Division of Geriatric Medicine at UBC, and Department of Psychology, University of Iowa, was published today in the Archives of Internal Medicine.
Over the course of six months, the study team followed 86 senior women with probable mild cognitive impairment. The randomized controlled trial is the first to compare the efficacy of both resistance and aerobic training to improve executive cognitive functions - such as attention, memory, problem solving and decision making - necessary for independent living. The trial also assessed the effect of both types of exercise on associative memory performance and corresponding functional brain plasticity.
Both types of exercise were performed twice weekly for six months. Participants were measured with a series of cognitive tests and brain plasticity was assessed using functional MRI. The results showed resistance-training significantly improved executive cognitive functions, associative memory performance, and functional brain plasticity. In contrast to previous studies in healthy older adults, aerobic training did not demonstrate any significant effect for cognitive and brain plasticity.
"There is much debate as to whether cognitive function can be improved once there is noticeable impairment," says Liu-Ambrose, "What our results show is that resistance training can indeed improve both your cognitive performance and your brain function. What is key is that it will improve two processes that are highly sensitive to the effects of aging and neurodegeneration: executive function and associative memory -- often impaired in early stages of Alzheimer's disease."
This work builds on the same researcher team's Brain Power Study, published in the January 2010 issue of Archives of Internal Medicine and July 2011 issue of Neurobiology of Aging, which demonstrated that 12 months of once-weekly or twice-weekly progressive strength training improved executive cognitive function and functional brain plasticity in healthy women aged 65- to 75- years- old and provided lasting benefits.
Coinciding with the study, the team has developed and launched an informative video of the resistance training exercises used in the study.

"Exercise is attractive as an prevention strategy for dementia as it is universally accessible and cost-effective," says Liu-Ambrose, who is who is also an assistant professor, in the Department of Physical Therapy at UBC and a Michael Smith Foundation for Health Research and CIHR New Investigator scholar. "By developing this YouTube video we can help translate our findings directly to the senior population and fitness instructors who are working with them." Cognitive decline among seniors is a pressing health care issue for this province. The number of seniors in B.C. is expected to increase by 220 per cent by 2031, representing 23.5 per cent of B.C. population. Effective strategies to prevent cognitive decline are essential to improving quality of life for older British Columbians and to save the healthcare system millions in associated costs.
Provided by University of British Columbia

Cognitive decline can begin as early as age 45: study

The brain's capacity for memory, reasoning and comprehension skills (cognitive function) can start to deteriorate from age 45, finds research published in the British Medical Journal today.

06 jan 2012--Previous research suggests that cognitive decline does not begin before the age of 60, but this view is not universally accepted.

Researchers, led by Archana Singh-Manoux from the Centre for Research in Epidemiology and Population Health in France and University College London in the UK, argue that "understanding cognitive ageing will be one of the challenges of this century," especially as life expectancy continues to rise.

They add that it is important to investigate the age at which cognitive decline begins because medical interventions are more likely to work when individuals first start to experience mental impairment.

Therefore the authors observed 5,198 men and 2,192 women over a 10-year period from 1997. They were all civil servants aged between 45 and 70 and were part of the Whitehall II cohort study established in 1985.

Participants' cognitive functions were assessed three times over the study period. Individuals were tested for memory, vocabulary and aural and visual comprehension skills. The latter include recalling in writing as many words beginning with "S" (phonemic fluency) and as many animal names (semantic fluency) as possible.

Differences in education level were taken into account.

The results show that cognitive scores declined in all categories (memory, reasoning, phonemic and semantic fluency) except vocabulary and there was faster decline in older people.

The findings also reveal that over the 10-year study period there was a 3.6% decline in mental reasoning in men aged 45-49 and a 9.6% decline in those aged 65-70. The corresponding figures for women were 3.6% and 7.4%.

The authors argue that robust evidence showing cognitive decline before the age of 60 has important ramifications because it demonstrates the importance of promoting healthy lifestyles, particularly cardiovascular health, as there is emerging evidence that "what is good for our hearts is also good for our heads."

They add that targeting patients who suffer from one or more risk factors for heart disease (obesity, high blood pressure and high cholesterol levels) could not only protect their hearts but also safeguard them from dementia in later life.

In an accompanying editorial, Francine Grodstein, Associate Professor of Medicine at Brigham and Women's Hospital in Boston, says the study "has profound implications for prevention of dementia and public health."

She adds that more creative research, perhaps using telephone and computer cognitive assessments, needs to be undertaken.

Provided by British Medical Journal