Biological organ ages predict disease risk decades in advance

The findings, published in The Lancet Digital Health, show how accelerated ageing in specific organs can predict not only diseases affecting that organ, but diseases across the rest of the body as well.

Lead author Professor Mika Kivimaki (UCL Faculty of Brain Sciences) said: "Our organs function as an integrated system, but they can age at different rates. Ageing in particular organs can contribute to numerous ageing-related diseases, so it's important for us to take care of all aspects of our health.

"We found that a quick and easy blood test can identify whether a specific organ is ageing faster than expected. In years to come, blood tests like this could play a crucial role in preventing numerous diseases.

"I believe that in the future of healthcare, the prevention of age-related diseases could begin much earlier, prioritising those who would benefit most and tailoring interventions to individual risk profiles."

The research team, led by scientists from UCL Brain Sciences, the UCL Institute of Healthy Ageing, Stanford University, Inserm, and the University of Helsinki, analysed data from participants from the British Whitehall II study, a longitudinal cohort study that has been running since 1985 and is now led by Professor Kivimaki as Director.

The researchers analysed blood samples collected in the late 1990s from over 6,200 middle-aged adults to determine the biological age of nine organs (heart, blood vessels, liver, immune system, pancreas, kidneys, lungs, intestines, and the brain) and for the entire body. They measured the gap between a person's chronological (actual) age, and the assessed biological age of each of their organs as determined by markers of ageing specific to that organ, finding that organs often aged at different rates in the same person.

Participants' health status was tracked for 20 years through national health registries. By the end of the follow-up period, they were aged 65-89, and many had been diagnosed with at least one of the ageing-related diseases investigated in this study.

Follow-up data revealed that accelerated organ ageing predicted the risk of 30 different diseases over the next 20 years in initially healthy people. For instance, a heart that aged more rapidly predicted significantly increased risk of cardiovascular diseases, while people with accelerated lung ageing were predisposed to respiratory infections, chronic obstructive pulmonary disease (COPD), and lung cancer.

Surprisingly, the highest risk of dementia was found in those whose immune system aged faster than usual -- not in those whose brains aged more rapidly in midlife. The scientists say this result supports previous findings that people prone to severe infections are also at higher risk for dementia later in life. The finding also suggests that inflammatory processes may play a key role in the development of neurodegenerative diseases.

The researchers found that kidney health was particularly linked to other organs, as people with accelerated kidney ageing were more likely to later develop vascular disease, type 2 diabetes, and liver diseases, while biological ageing of nearly all organs predicted increased risk of kidney disease.

The researchers say that as our organs function in close coordination, accelerated ageing in one organ can impair the function of others, which may explain why people with a rapidly ageing organ were particularly prone to experiencing multiple age-related diseases across different organs.

For many years, blood biomarkers (measurable indicators of health) were measured individually, making the process costly and inefficient, especially when analysing multiple markers. Over the past decade, technological advancements have progressed rapidly, and today, thousands of proteins can be measured simultaneously from a single blood sample.

Blood protein concentrations fluctuate in response to environmental factors, lifestyle, diseases, and medications. As a result, new proteomic (protein-based) analyses offer a valuable window into monitoring the pace of ageing.

The researchers say their findings support a future shift in healthcare toward more personalised and effective disease prevention. With proteomic signatures of organ ageing, risk of age-related diseases can be identified earlier, preventive measures can be targeted more effectively, and interventions can be tailored to each person's risk profile.

Professor Kivimaki added: "We hope our findings could contribute to new ways of helping people stay healthy for longer as they age. Blood tests may advise whether a person needs to take better care of a particular organ, and potentially provide an early-warning signal that they may be at risk of a particular disease."

This study was supported by Wellcome, the Medical Research Council, the US National Institutes of Health, and the Research Council of Finland.