Amuse it or lose it

Could taking early action against high blood pressure prevent impaired brain function? Or perhaps more time hugging or being hugged by a loved one, a good night’s sleep and some relaxation can ensure healthy cognitive function later in life. UTS Faculty of Science honours student Mariam Chaalan is researching how the way we live our lives affects our chances of developing cognitive medical conditions.

Cognitive function is how the brain’s process of awareness or thought occurs and includes a range of mental practices which are active when we access, process or store information. How we think, feel and sense things all feed into our cognitive functioning and influence our responses to problem solving, reasoning, creativity, memory and speech.

Chaalan’s research is focussed on how lifestyle influences cognitive ability. Mild cognitive impairment is not only associated with medical and health-related problems, but also increasingly recognised as a social and economic issue impacting individuals and the wider community.

“Research shows that people who have mild cognitive impairment may go on to develop serious illnesses, such as dementia and more notably, Alzheimer’s disease,” Chaalan says. Treating serious cognitive diseases – like Alzheimer’s – impacts dramatically on the Australian healthcare system. Treatment, residential and carer payments cost the Australian public up to $3.6 billion a year. With an ageing population, the number of people with dementia and serious cognitive disabilities is on the rise.

“It would be of great benefit to society if we could intervene before serious cognitive conditions develop,” says Chaalan. To help combat the problem, she is conducting tests to look for biomarkers which could lead to the early identification of mild cognitive impairment.

Senior Lecturer in the Department of Medical and Molecular Biosciences, Dr Sara Lal is Chaalan’s principal supervisor who proposed the initial study concept of investigating physiology and brain activity association to cognitive function. Dr Craig McLachlan, co-supervisor, introduced to the project ideas on blood pressure associations, and medical sciences officer Budi Jap is advising on some technical aspects of the research.

Much of Chaalan’s testing focuses on the link between blood pressure and a decline in cognitive function. So far she has tested 61 people for up to two hours each using a series of information processing exercises, including neuropsychological testing which is commonly used to measure patients’ cognitive functions in hospitals.

Chaalan’s tests are structured to measure cognitive awareness and function in a number of areas, including constructional ability, memory and calculations. Exercises include spatiality testing using geometric puzzles and recall memory tests where the subject is shown a picture and asked to re-draw shapes from memory.

Language ability is measured through a number of variables, including speech, comprehension, repetition and naming exercises. A person’s ability to use reason is also tested through a process of citing scenarios and requesting responses to hypothetical situations.

“The testing shows that high diastolic blood pressure (the lowest pressure during the resting phase of the cardiac cycle) was related to decline in cognitive function,” Chaalan says.

“It is not just high blood pressure that could be a biomarker to identify impaired cognitive function, our results also reveal that a greater difference in inter-arm blood pressure – where one arm has a different blood pressure reading to the other – has an association with cognitive impairment. We also see that an unhealthy lifestyle factors such as poor diet, smoking and excessive alcohol intake are related to impaired cognitive function.

“On the other side of the equation, the giving and receiving of affection appears to be associated with greater cognitive function. So lifestyle factors appear to influence cognitive function.”

This means a happier individual could be a healthier individual cognitively. Those who participate in regular physical activity, exercise or have a lower body mass index, are less likely to have reduced cognitive function.

During testing, brain activity revealed itself as another potential marker of cognitive function in Chaalan’s study.

“Our results show that those with impaired cognitive function have higher delta activity. Your delta brain function – which is the brain’s activity when it is in a sleepy, drowsy state or a lowered state of alertness – may be a biomarker in the future.”

Further studies could develop screening tools which show that any of these biomarkers, including differences between inter-arm blood pressure readings, could show early cognitive decline and hypertension.

Lal says the study is unique with novel findings for lifestyle and physiological associations with impaired cognitive function in its early stages.

“What we are hoping for here is for Mariam’s study to provide some physiological markers for impaired cognitive function,” Lal says. “If intervention can prevent the development of impaired cognitive function later on, Mariam’s studies can lead to identifying when these treatments need to begin.”

Chaalan plans to present a paper at this year’s two-day Scientific Research Meeting at the Royal North Shore Hospital. The conference is a collaborative effort between UTS, University of Sydney, Kolling Institute of Medical Research and Royal North Shore Hospital and aims to foster the research connections between education and industry.

(Source: University of Technology Sydney: November 2008)