The age composition of Australia’s population is projected to change considerably over the coming decades, with elderly Australians the fastest growing proportion of the population. This is particularly true of the centenarians, the exceptional group of individuals who reach the age of 100 and beyond. According to the Australian Bureau of Statistics, in June 2015, there were 29,612 individuals in Australia aged 95-99 years old, and 4,279 who were aged 100 or more. It is estimated that there will be 12,000 centenarians in Australia by 2020 and 50,000 by 2050. The number of centenarians worldwide is estimated to increase 15-fold, to 2.2 million by 2050.
Despite the rapid ageing of our population there have been only a few population-based studies of centenarians and near-centenarians internationally, and none in Australia. The study of exceptionally long-living individuals may shed light on the determinants of successful aging, both environmental and genetic. It will also help us understand the health care requirements of this group and enable us to better plan for the future. This was the rationale for starting the Sydney Centenarian Study in 2008.
Individuals 95 years and older have been recruited from seven electoral districts in Sydney using the electoral roll, Medicare registers and multiple other strategies to obtain a representative sample. Physical health, mental health and cognitive status are assessed using standard instruments over multiple sessions in our participants’ places of residence, with assessments adapted to each individual as needed. An ‘informant’ (i.e. someone who knows the participant well) is also interviewed, and participants are invited to provide a blood sample, undergo an MRI scan and enrol in our brain donation program.
To date the study has included 369 participants from within our catchment area as well as 56 from other areas of Sydney. The mean age of our participants is 97.4 years, ranging from 95-106. Males have comprised 28.1% of the cohort and 58.3% of participants were living in private accommodation. Rates of heart disease and diabetes were lower than in octogenarians, but hearing and visual deficits were common. The mean mini-mental state examination (MMSE) score was 22.5. Rates of psychological distress have been low and satisfaction with life high. Approximately 35% of participants demonstrated impairment in cognition and function to a degree suggestive of dementia.
We also know that genetics plays a role in determining exceptional longevity, with the importance of genetic factors becoming stronger at the upper limits of the lifespan. Many of our SCS participants have kindly donated samples for genetics and epigenetics testing. Epigenetics refers to mechanisms that alter gene expression that are not due to alterations in the DNA coding sequence such as DNA methylation. We have a number of ongoing genetic and epigenetic studies. Currently we have two PhD students examining the roles of genetic and epigenetic variation (DNA methylation) in exceptional longevity. We are also profiling the expression of genes using the latest methodologies, including RNA sequencing that provides a snapshot of what genes are active or inactive at a particular point in time.
In summary, the Sydney Centenarian Study is an ongoing project that has established a representative cohort of very elderly Australians. It has provided evidence that dementia is not inevitable at this age and that independent living is common. The data collected to date provides an excellent resource to explore the genetic and environmental factors that contribute to long life and successful cognitive aging. The study is ongoing and actively recruiting, with numerous publications in preparation.
The Sydney Centenarian Study has the following aims;
· To determine the cognitive profile of exceptionally old individuals
· To relate cognition in this age group to brain imaging parameters
· To examine the current health, medical history, lifestyle and genetics of the exceptionally old
· To examine the health care needs and level of functional independence among the very old
Why do we want to study people in this age group?
Centenarians are the fastest growing age group. This will pose a number of challenges to our health care system. Research is needed to assist the public health system to better plan for the future. Research may also assist younger people to make better lifestyle choices. People aged 95 and above represent a unique population that can inform us about successful ageing, factors that contribute to longevity, and the course of ageing after 95.
What does the assessment involve?
The initial assessment is typically held over two visits to our participant’s home. Staff will ask about your medical history, memory, emotional well-being, physical activity, diet, social network, and a number of other areas. You will also be invited to participate in a brief physical exam to measure your blood pressure, walking ability, lung capacity, grip strength, and vision.
With your consent we will also interview a family member or friend to ask some questions about your health, memory, and general functioning. You will also be invited to give a blood sample (taken by an experienced venepuncturist in your own home) and have an MRI scan at the Prince of Wales Hospital (our staff will provide transport).
Participants and Informants are invited to complete brief, follow-up assessments every 6 months.
Who is eligible to participate in the Sydney Centenarian Study?
Any individual aged 95 or above who lives within the Randwick, Waverley, Woollahra, Botany, Rockdale, Ashfield or Marrickville local government areas are eligible to join the Sydney Centenarian Study.
If an individual aged 95 or above lives outside of this geographic area, they may participate in the study if they are able and willing to have an MRI scan (our staff will provide transport).
If an individual aged 100 or above lives outside of our catchment area they are eligible to participate in the study if they are able and willing to provide a blood sample (collected in their own home by experienced staff).
How can I find out more?
If you are aged 95 or more, or have a friend or relative who is aged 95 or more who might be willing to participate in the Sydney Centenarian Study, please contact the Study Coordinator (Adam Theobald) on (02) 9385 0433 or via email email@example.com
Many of our referrals come from nursing homes and retirement communities. If you work in an aged care facility and would like to refer someone who may be willing to participate, our Study Coordinator would love to speak with you.
Any individual aged 95 or above who lives within the Randwick, Waverley, Woollahra, Botany, Rockdale, Ashfield or Marrickville local government areas are eligible to join the Sydney Centenarian Study. If an individual aged 95 or above lives outside of this geographic area, they may participate in the study if they are able and willing to have an MRI scan (our staff will provide transport). If an individual aged 100 or above lives outside of our catchment area they are eligible to participate in the study if they are able and willing to provide a blood sample (collected in their own home by experienced staff).