Treating the Causes of Aging Seen through the Lens of Treating Multimorbidity
This popular science article takes an approach that seems useful when presenting the argument for treating aging as a medical condition to people who are entirely unfamiliar with the concept. At present the practice of medicine treats the symptoms of aging only, addressing each symptom - each age-related condition - separately. But most old people have numerous conditions, stemming from the same underlying causes, the causative mechanisms of aging. It only makes sense to address age-related conditions more efficiently, and the path to that goal is to target these deeper causes of aging, thereby treating numerous age-related conditions with one intervention.
Over half of UK adults over the age of 65 live with two or more long-term health conditions - commonly known as multimorbidity. Crucially, over half of GP consultations and hospital appointments involve patients with multimorbidity. In the UK, care for people with multimorbidity is also estimated to take up to 70% of health and social care expenditure.
Multimorbidity is currently managed by treating each disease separately. This means people will need to take multiple medications at the same time (known as polypharmacy), and will also have to attend multiple medical appointments for each condition. Not only can this put a strain on the NHS, polypharmacy can also put patients at increased risk of negative drug interactions and unintended harm. There's a clear need to improve the way multimorbidity is treated. But research shows that to do this, we need to instead start looking at targeting the key causes of multimorbidity when searching for treatments.
Although multimorbidity differs for each person, we know that patients tend to suffer from the same groups of diseases - known as "clusters". This suggests that each cluster may share a common underlying cause. For example, a person with multimorbidity may suffer from heart problems (such as heart disease and high blood pressure) and diabetes, which may all stem from the same cause - such as obesity. Identifying and treating the cause of a patient's disease clusters would allow us to more effectively combat several - or even all - of the diseases a patient has using a single treatment.
Such an approach has not yet been taken, in large part because medical research and drug discovery tends to focus on treating a single disease. Importantly one of the biggest risk factors for developing multimorbidity is getting older. This is why researchers think targeting the biological causes of ageing could be one way of treating multimorbidity, by preventing clusters of diseases from developing in the first place.
For example, we become less able to remove senescent cells from our body as we get older, causing them to accumulate and increase our risk of disease. Researchers think that if we could prevent these cells from building up, we may be better able to prevent multimorbidity from happening to begin with. Drugs which can kill senescent cells (called senolytics) already exist, and are currently used to treat certain types of leukaemia, and are now being trialled on patients with the chronic lung condition idiopathic pulmonary fibrosis. Given that senolytics are already in clinical use, this means they could quickly be repurposed for use in patients with multimorbidity if proven to be effective on other conditions too.