Heart test can show dementia risk up to 25 years before diagnosis

People with poor heart health in middle age are more likely to be diagnosed with dementia in later life, research suggests. A study of 6,000 people found those who developed the condition had elevated levels of a protein called troponin, which indicates heart muscle damage, up to 25 years before diagnosis. Participants with high troponin at the start of the study were 38% more likely to develop dementia.

Study author Professor Eric Brunner, an expert in epidemiology and health at University College London, said: "Damage to the brain seen in people with dementia accumulates slowly over the decades before symptoms develop. Control of risk factors common to both heart disease, stroke and dementia in middle age, such as high blood pressure, may slow or even stop development of dementia as well as cardiovascular disease."

Troponin levels are often checked by doctors when they suspect a patient has suffered a heart attack.

Elevated levels without symptoms can also indicate ongoing damage to the heart muscle of problems with its function. This can have a knock-on effect, impacting blood vessel health and blood flow to the brain.

Researchers analysed data from the Whitehall II study, which has followed civil servants since 1985.

All participants had a troponin test between the ages of 45 and 69, then were tracked for an average of 25 years. Some 695 were diagnosed with dementia.

Prof Brunner added: "We now need to carry out studies to investigate how well troponin levels in the blood can predict future dementia risk.

"Our early results suggest that troponin could become an important component of a risk score to predict future probability of dementia."

Professor Bryan Williams, chief scientific and medical officer at the British Heart Foundation, which part-funded the research, said: "This study is an important reminder that our heart and brain health are inseparable.

"Our advice to focus on heart health throughout life also gives our brains the best chance of ageing well. That means keeping our blood pressure under control, managing our cholesterol levels, staying active, maintaining a healthy weight, and not smoking.

"This also underscores why the British Heart Foundation is investing £10 million into its Centre for vascular dementia research, alongside the UK Dementia Research Institute, to find better ways to prevent and treat the devastating impact of vascular dementia."

The findings were published in the European Heart Journal.