Determining risk factors for dementia

A Dalhousie University study focusing on risk factors for dementia could change our overall approach to health and aging, says Dr. Kenneth Rockwood.

The Kathryn Allen Weldon Professor of Alzheimer Research applied an index of health variables —from abdominal pain, to denture fracture, to urinary tract infections—none of which independently had any connection to dementia, to comprehensive data from the Canadian Study on Health and Aging.

“We measured 19 variables and after people had five or more – any five – the risk of dementia increased,” says Dr. Rockwood. “And the the risk was strong enough that it defeated all of the traditional risk factors.”

The 7,000 older adults in the original study, on which Rockwood also worked, had no cognitive impairment at baseline.

“The hypothesis worked out as planned but it is quite amazing to stand there and look at it play out that way,” he admits.

The study was prompted chiefly by Dr. Rockwood's observations in his daily work as a Nova Scotia geriatrician.

“We don't look after people who have one thing wrong,” he notes. “We specialize in people with multiple, interacting social and medical problems. And we see that any single illness, when it takes place in people with many other things wrong, does not look a lot like that single illness when it takes place in people who don't have anything else wrong.”

Reconsidering medical care for seniors

The report could impact the way in which the health system approaches ill seniors.

“There's a different way to do our work when people have multiple things wrong. The traditional model assumes away many other things that people have wrong. Our model embraces it,” says Dr. Rockwood.

“This doesn't have anything to do with dementia per se. It's about increasing recognition that as people get older—particularly in the 9th and 10th decades—the line between disease and age is an artificial one.”

But Dr. Rockwood admits he's already encountered resistance to that notion: “Sociologists hate this – they say 'You are medicalizing old age.' But the approach we have right now is focused too much on single illnesses and not on the people in whom many illnesses occur. We need to step back and look at the big picture.”

The next step is producing a data set in which the illness of interest is not dementia – perhaps focusing on heart disease to test the same theory.