It is massive in scope, logistically challenging and runs until 2033, but the Canadian Longitudinal Study on Aging is already providing insights into the process of aging, says its lead investigator.
“More people are living longer worldwide, yet we have very little data that allows us to advance the science of aging or to inform policies and programs at the federal, provincial and municipal level,” said Parminder Raina, a geriatric epidemiologist and holder of the Canada Research Chair in Geroscience at McMaster University. “There is a great need for longitudinal data so we can understand what triggers sudden trajectories that people take as they age and what influences those trajectories.”
Dr. Raina said he first became interested in how we age from observing his own grandparents. “My mother’s parents didn’t live so long and they didn’t have a particularly healthy aging process,” he said. “My mom’s side was a lot wealthier than my dad’s, but everyone on my dad’s side seemed to live forever. That always stayed in the back of my mind. Is it the environment, social factors, nutrition or genetics that created this differentiation?”
looking at aging through an aging lens
The CLSA, which Dr. Raina said is the most comprehensive study on aging ever undertaken in Canada, will help to answer those questions. What makes this study different from other initiatives around the world is that “we are looking at aging through an aging lens, not a disease lens,” he said. “It is a person-centred approach, and the question is: Why do some people age in a healthy fashion and some don’t?”
Between 2010 and 2015, investigators recruited more than 50,000 men and women aged 45 to 85 and collected baseline biological, medical, psychological, social, lifestyle and economic information. The study has now entered its next phase where participants are being contacted for their first follow-up, a process that will take until 2018.
Twenty-thousand participants are being monitored through in-depth phone interviews, while the remaining 30,000 are assessed through home interviews and visits to 11 CLSA data collection sites across Canada. There they undergo physical examinations, cognitive exercises, bone density, blood and urine analyses as well as interviews on topics ranging from nutrition to elder abuse. Information will be collected every three years until 2033, or death.
Bruyère Continuing Care, in partnership with the University of Ottawa, is one of the CLSA data collection sites. “Investigators are salivating to get their hands on this data,” said site coordinator Helen Niezgoda. “It’s going to answer some really important questions on aging. This will be a data library for decades to come.”
Data from the participants will be kept and used for research for 25 years after 2033. After that, an ethics board will be consulted to determine the future of remaining samples and data.
data will be immediately accessible
Olive Bryanton is one of the study participants, although she may not be typical of her cohort. At age 79, she is currently doing her PhD in education at the University of Prince Edward Island, studying women 85 and older. Ms. Bryanton said she likes the fact that the CSLA data will be immediately accessible. “It will be there for future generations but the research is also going to be available throughout the study. So researchers will be using it to learn from as the study goes on.”
Even though it is still relatively early days, dozens of investigators have filed applications to use the data. “We created a frailty index using data from the CLSA and were able to conduct a preliminary assessment of its validity by examining the association between our index and other variables that we know are associated with frailty,” said Lauren Griffith, an associate scientific director of the CLSA and an associate professor in the department of clinical epidemiology and biostatistics at McMaster. The next step, she said, is to see how this measure predicts health outcomes over time.
“Aging is a developmental process”
Partners in the study include more than 160 researchers and experts in areas such as biology, genetics, economics, psychology and epidemiology at 26 Canadian universities. The co-principal investigators are Susan Kirkland, associate director of the geriatric medicine research unit at Dalhousie University, and Christina Wolfson, senior scientist in the brain repair and integrative neuroscience program at McGill University. The Canadian Institute for Health Research is contributing $65.1 million in funding for the study, with an additional $10 million coming from the Canada Foundation for Innovation.
In 2015, Statistics Canada reported that, for the first time, there were more people over the age of 65 than under the age of 15 in this country. It also predicts that, by 2030, one in five Canadians will be over the age of 65.
For his part, Dr. Raina, age 54, doesn’t think of himself as “getting older.” Rather, “I think aging is something that starts the day we are born. The only difference is that in the early years there are a lot of developmental gains and in later years there are a lot more developmental losses. I see it as a developmental process. That’s why it interests me.”