Assoc Prof Ng Tze Pin: Evidence-based approach to healthy ageing

Countries around in the world are seeing a rise in both the number and the proportion of older persons in their populations. In Singapore, it is estimated that by 2030, one in four people will be over 65 years of age, and this will rise to almost one in two by 2050. Dubbed the ‘silver tsunami’, the rapidly ageing population brings about implications and impacts to Singapore’s economy and society.

Through investing in health promotion and disease prevention, seniors are likely to live longer in good health and continue to actively contribute to the society. Against this backdrop, in 2000, Associate Professor Ng Tze Pin from the Department of Psychological Medicine at the NUS Yong Loo Lin School of Medicine spearheaded a research programme on ageing and health known as the Singapore Longitudinal Ageing Studies (SLAS). Here, he shares what led him to embark on the project, and research findings over the past 20 years.

Q: What sparked your interest in epidemiology and public health?

A: During my medical training in the early 1980s, I had considered to specialise in orthopaedic surgery. It was fascinating to see how almost miraculously, fingers and arms could be surgically re-attached. However, this took a turn when I realised that numerous cases of hand injuries were caused by industrial ‘accidents’ which were entirely preventable. I then decided to switch to public health and occupational medicine. The science and practice in this field is population data-driven, and the basic skill set is epidemiology and statistics. This is how I find myself doing population-based studies in ageing today, most of which was self-taught.

Q: What led you to study ageing?

A: In keeping with the needs of the times, my initial research forays were in occupational pulmonary diseases. As polluting industries gave way to high value-added manufacturing, and life expectancy dramatically improve, I made a switch to ageing research and this was primarily led by the trends in population ageing.

In the 1990s, my medical colleagues noted the dire healthcare and social support problems of aged patients amidst the increasing nuclearisation of families. However, there was not much support for ageing research. I admired and learned from these colleagues. Looking back, I think they were too much ahead of the times.

Q: When did you start the Singapore Longitudinal Ageing Studies (SLAS) research programme? What are some of the challenges you had encountered?

A: I embarked on the programme to research on ageing and health in 2000. The timing could not have been better, because soon after, “silver tsunami” became a buzzword. The nation saw an astonishing rapid rate of population ageing that will see one in four Singaporeans being over 65 years of age by 2030.

The 2000s also saw the beginnings of unprecedented funding opportunities for research, when Singapore was committed itself to building a knowledge-based economy and support for research and development. The Agency for Science, Technology and Research, and the Biomedical Research Council provided ample support for the SLAS research. I was fortunate to be able to secure uninterrupted funding for the research programme entirely through competitive individual research grants over 20 years.

The SLAS project was not only both resource-intensive and challenging, it was exceptionally ambitious. The project sought to recruit and follow up a large cohort of older Singaporeans from middle age (55 years and above), and study the changes in their health as they age in the remaining decades of their lives.

Besides helping to better understand how Singaporeans age in their uniquely Asian contexts, SLAS hopes to provide vital data that inform health policy planning and implementation.

Q: What data did you collect and examine?

A: We have gathered an exceptionally huge amount of baseline information on socio-demographic, cognitive, psychological, behavioural, physical, biological, and healthcare data on two large cohorts of about 6,000 older Singaporeans in total. We re-assess them every three to five years, from which we document the onset and progression of various health states, including dementia, depression, frailty and healthy ageing.

We have also collected and archived blood specimens for analyses of blood biomarkers, anticipating the future potential of -omics technology to analyse hundreds and thousands of biomarkers altogether in a single tiny drop of blood.

SLAS also conducted interventional studies to test the effectiveness of lifestyle and behaviour interventions for frailty and predementia.

Q: Are there any findings from SLAS over these two decades that you find particularly significant?

A: 20 years ago, nobody could venture to say confidently that dementia is preventable. Today, there is wide consensus that we now have the knowledge and means to ‘age without dementia’. In Singapore, we know confidently what the risk and protective factors are among older Singaporeans that influence our likelihood of getting dementia. With all that, you can use a simple score card to estimate what are your risks of developing emergent dementia over the next three to five years.

Geriatricians used to say this 20 years ago - “I can’t diagnose frailty, but I can recognise frailty when I see it in a patient”. After two decades of research, frailty has taken centre-stage as a diagnosable geriatric syndrome and population health issue. Today, in Singapore, there is more than enough knowledge and data of older Singaporeans for us to implement evidence-based intervention programmes to prevent and treat frailty. This will greatly help to reduce the prevalence of functional dependency in our older population. This is also the key to promoting healthy ageing.

Q: What are the key achievements of SLAS?

A: The SLAS research has been highly successful in contributing to the exponential growth in global knowledge about ageing and health in the past 20 years. It has also provided useful and vital policy-relevant information about ageing in Singapore.

The recent past 5 to 10 years of SLAS research have extended to interventional studies that established in-principle effectiveness of multi-domain lifestyle interventions targeting risk and protective factors for evidence-based prevention of physical frailty and mild cognitive impairment (MCI) or early dementia. In 2017, a National Innovation Challenge trial project demonstrated the effectiveness and feasibility of implementing multi-domain lifestyle interventions among individuals with high risk scores for dementia in neighbourhood senior activity centres.

The SLAS research identified pre-frail and frail older Singaporeans as an important vulnerable group with significant risk of dementia, disability and mortality. In 2015, the publication of a pivotal randomized control trial on pre-frail and frail seniors in the community showed in principle that frailty is reversible; nutritional, cognitive training and physical exercise interventions effectively improve physical mobility, cognitive and mood functioning. This provides the important evidence base for designing and implementing innumerable modalities and forms of community-based lifestyle interventions for frailty prevention and reduction, and promoting healthy ageing.

The SLAS research findings have just only begun to be exploited for its knowledge translation value. Distinctly in medicine and healthcare, research information and knowledge take decades before being translated into useful policies and practices for improving health outcomes. However, I am happy to learn that policy planners and decision makers have begun to take note of the findings. I believe that we can all look forward in the years ahead to see Singaporeans living not only longer, but much healthier lives into their 100s.

Q: What is the next stage of your research?

A: The SLAS research programme is ongoing. It is an open population-based research platform that welcomes research collaborations across diverse disciplines to answer basic and pragmatic questions about human ageing. There are still much data that remains to be mined for their research value, and more extension research projects can be built upon the SLAS population cohort platform. As we seek to understand the underlying biology of ageing, the holy grail of research is to measure biological ageing, and reverse the ageing process in the quest for healthy longevity.

Q: In your opinion, what makes SLAS such a successful long-term cohort study?

A: The SLAS research programme owes its success to a large collaborative team of multidisciplinary researchers, including passionate clinicians who commit their spare moments away from their busy clinical work to collaborate with us on the research. The core research team of research fellows, assistants and nurses stood out for their faith and commitment to the cause. Many thanks and credits to the SLAS core research team, both past and present, for their valuable efforts and contributions.