Kidney disease: How to protect yourself and the symptoms the NHS may not spot
The UK is facing an unprecedented kidney disease crisis, one which could cost the NHS up to £11 billion per year by 2033 if left unchecked. This is due to the number of patients with chronic kidney disease ending up on dialysis machines, due to one or both kidneys failing, a growing demand which threatens to overwhelm the health service.
According to a report from the charity Kidney Research UK, there are currently 30,000 people in the UK who require dialysis, a number which is predicted to rise to 143,000 in the next decade.
Crucially, the charity’s findings indicated that one of the problems is that patients are typically being diagnosed too late, with the signs of kidney disease only spotted once the disease is at a more advanced stage.
“This is concerning because if chronic kidney disease is caught earlier, there may be a better chance to stop progression to kidney failure,” says Dr Tom Oates, a consultant nephrologist at Barts Health NHS Trust. “In some cases, stopping progression may not be possible, but we know that even in these cases, early detection is associated with better outcomes when patients start dialysis.”
So why are these cases being missed, and what is driving the UK’s rising rates of kidney disease?
Soaring diabetes and high blood pressure
The kidneys are among the hardest working organs in the body, filtering problematic waste products and excess water from the blood and using that to produce urine.
“About 20 per cent of the blood that your heart pumps out with every heartbeat is to drive your kidneys to do their job,” says Dr Adnan Sharif, a consultant nephrologist and transplant physician at University Hospitals Birmingham. “So they’re working very hard and they are quite susceptible to injury.”
To perform this filtration, the kidneys contain millions of miniature sieves, each constructed from tiny blood vessels which are among the first to be damaged by elevated blood sugar and blood pressure. The rising rates of chronic kidney problems are thought to reflect the soaring numbers of people with Type 2 diabetes and hypertension, while chronic kidney damage can also be induced by genetic conditions along with some autoimmune conditions like lupus and use of long-term painkillers like ibuprofen.
The fragility of the internal structures within the kidneys mean that people can also incur acute kidney injuries through becoming excessively dehydrated and through infections, particularly those that require hospitalisation. During the pandemic, Royal United Hospitals Bath found that out of 4,000 hospitalised Covid patients, 46 per cent developed acute kidney injuries.
Few warning signs
But the great paradox of the kidneys is that despite being inherently fragile, they are also remarkably resilient, and able to keep plugging away despite significant levels of damage. Sharif points out how there are cases of people born with a single kidney, who had no idea until they received a scan.
As a result, repeated studies have indicated that chronic kidney disease is underdiagnosed. Last year, a study from data analysts at King’s College London identified that far fewer people in London were being diagnosed with the condition than would be expected from population estimates, suggesting that many cases are being missed until a much later stage.
Sharif says: “10 to 15 per cent of the British population probably has an element of kidney disease, which is quite a frightening statistic. But you will not know that your kidney function is working at a bit less than 100 per cent. People don’t develop any symptoms until things are quite advanced. We’ve even had patients whose kidneys had failed, and they presented with very few symptoms – they just felt very non-specifically unwell, a bit tired and lethargic and they happened to get a blood test. So that’s the reason why there’s so much kidney disease out there and people may be unaware.”
Specialists refer to the five stages of kidney disease in terms of severity with red-flag signs, such as the appearance of blood in the urine, typically not occurring until patients are approaching stage five, at which point their kidneys may be operating at less than 30 per cent of their normal capacity.
So, what can you do to find out how yours are functioning? Anyone between 40 and 75 is entitled to a free NHS health check from their GP, and Sharif advises asking your practitioner for a kidney function check, particularly if you have smoked or are overweight or have family risk factors for diabetes or high blood pressure. This typically involves a simple urine test which can be checked for elevated levels of proteins such as albumin, a tell-tale sign of kidney damage.
“It’s very straightforward,” he says. “Any practice nurse can quickly do a dipstick check and make sure there’s no blood and protein in there. The earlier you can pick up kidney disease, the more you can do to stop the development of kidney failure.”
The hope of AI
In the coming years, specialists are optimistic that artifical intelligence (AI) will be able to help with the identification of at-risk patients. Initially, tools based on generative AI could help alert GPs that a particular patient is likely to require a kidney check, and then remind them to be appropriately coded if chronic kidney disease is identified, so they are properly monitored.
“For example, if they have been hypertensive or diabetic for a long time, they should have a blood and urine test,” says Dr Ellie Asgari, a consultant nephrologist at Guy’s and St Thomas’ NHS Foundation Trust.
AI-based software is already starting to be used in some specialist kidney clinics for patients with ADPKD, a common inherited kidney condition caused by the growth of fluid-filled sacs in the kidneys, which affects between 30,000 and 70,000 people in the UK. It is the third most common cause of kidney failure in the country.
At the University of Sheffield and Sheffield Teaching Hospitals NHS Foundation Trust, scientists and consultants are using one particular tool as a way of accelerating the time-consuming process of analysing scans. Capable of quantifying a patient’s total kidney volume from a scan six times faster than a human doctor, this measurement is used to predict whether the patient’s kidneys are at risk of failure.
“The use of AI tools is really in its infancy,” says Albert Ong, professor of renal medicine at the University of Sheffield, and one of the consultants who has been utilising the new technology. “The benefit is that it’s enabling us to scan and analyse more patients with early disease in order to obtain information that could predict their future kidney function. It helps identify those in the highest risk group that would benefit from early disease-modifying drugs to delay the onset of kidney failure.”
Ong predicts that in future, such tools could even be used in primary care, feeding back the results from scans to GPs.
Overall, specialists are hoping that more can be done to accelerate the early identification of kidney problems, as the sooner they are detected, the more that can be done to reverse the damage. For example, if someone has glomerulonephritis, an inflammatory condition which damages the tiny filters inside the kidneys and can be caused by lupus or other autoimmune problems, immunosuppressants can be given. Sometimes blood-pressure-lowering medications, such as angiotensin-converting enzyme inhibitors, can be prescribed to patients with signs of kidney problems to help protect the organs.
What helps, Sharif explains, is “minimisation of potential risk factors. It often depends on the underlying cause. So we will often talk to people about their use of painkillers. If diabetes is the cause of your kidney disease, then very good control of your diabetes will slow the progression and minimise your risk of kidney failure.”
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