The early warning signs of type 2 diabetes – the potentially deadly disease that can strike from middle age – can be spotted in children as young as eight, a groundbreaking British research project has revealed.
The discovery is just one of a raft of findings in recent years that have given scientists and doctors new insight into the high blood sugar condition and ways to prevent it, before any damage is done, by picking it up in its earliest stages.
A team at the University of Bristol analysed blood samples taken from thousands of children born in the early 1990s and found that many were already showing signs they might one day develop type 2 diabetes. But as startling as the discovery is, the researchers had an upbeat message: that illness wasn’t inevitable, and that determining risk and making changes at the soonest opportunity could stave off ill health.
A team at the University of Bristol analysed blood samples taken from thousands of children born in the early 1990s and found that many were already showing signs they might one day develop type 2 diabetes
It’s already known that some people carry a set of genes that make them more prone to type 2 diabetes. But the Bristol researchers found youngsters with these genes also had lower levels of a type of cholesterol in their blood known as HDL, which is important for clearing the arteries of fatty deposits
It’s already known that some people carry a set of genes that make them more prone to type 2 diabetes. But the Bristol researchers found youngsters with these genes also had lower levels of a type of cholesterol in their blood known as HDL, which is important for clearing the arteries of fatty deposits.
Low HDL is also often seen in adults with type 2 diabetes.
The children also had compounds in their blood linked to inflammation – an indication that the body is dealing with disease or illness. Importantly, children with the diabetes genes were also more likely to carry more body fat.
But other research has shown that being overweight as a child doesn’t increase the risk of type 2 diabetes, as long as you lose the weight.
Dr Joshua Bell at the University of Bristol, who led the study which was funded by the charity Diabetes UK, says: ‘You’d expect to see these changes in someone heading towards type 2 diabetes, but the novelty here was how early in life we could observe that. It shows what a lifelong process the path to type 2 diabetes is, although even with the genetic influence it’s not an inevitable one.’
At the moment about 400 genes linked to the development of type 2 diabetes have been identified. The more you have, the more at risk you may be.
The majority of these genetic faults affect the pancreas, a gland behind the stomach that produces the hormone insulin.
When we eat carbohydrates, such as bread and potatoes, they are broken down by the digestive system into single sugar molecules – most commonly, glucose – which is then absorbed into the blood.
Glucose is vital fuel for the body, and insulin, when released into the circulation by the pancreas, helps cells ‘burn’ it for energy. Type 2 diabetes occurs when, among other things, not enough insulin is produced, leading to sugar building up in the blood. This slowdown is due to fat building up inside the pancreas, which stops it working properly. Fat building up in the liver is another key factor.
Excess sugar is usually stored in the liver, but the organ is less able to do this if riddled with fat, meaning there is more glucose floating around in the blood causing damage. One study found that with every five per cent increase in liver fat, the risk of developing type 2 diabetes increased by 27 per cent. But why does this happen?
Only a quarter of people who have a body mass index (BMI) over 30 – defined as officially obese – will develop diabetes. Meanwhile, some people who appear relatively slim and healthy are diagnosed with the disease
It has long been observed that overweight people are more likely to develop type 2 diabetes. ‘For every kilogram of excess weight, your risk of developing type 2 diabetes rises,’ says Dr Nicola Guess, a diabetes researcher at the University of Oxford. ‘It’s quite easy to gain a kilogram in a weekend.’
But confusingly, only a quarter of people who have a body mass index (BMI) over 30 – defined as officially obese – will develop diabetes. Meanwhile, some people who appear relatively slim and healthy are diagnosed with the disease.
Scientists now understand the reason: where we store our fat is dictated by our genetic make-up.
Diabetes UK-backed research by Dr Hanieh Yaghootkar, a specialist in metabolic disorders at Brunel University London, found that some people have genes that mean excess fat is laid down mostly under their skin. But others have genes that mean fat is stored everywhere – including the liver and pancreas.
‘Some people can be overweight or obese throughout their life and stay healthy,’ says Dr Yaghootkar. ‘They never develop type 2 diabetes or other problems such as high blood pressure or heart disease. But we found they have a favourable genetic profile that means they don’t store fat in their organs.’
Dr Yaghootkar used data from the 500,000 volunteers involved in the UK Biobank study, which is monitoring their health throughout their lives. She found those who did store fat in their organs were more likely to end up with a range of different diseases, including type 2 diabetes.
Those with favourable genes aren’t always fortunate, though – they still ended up with other obesity-related problems, such as deep vein thrombosis, gout and osteoarthritis.
So how can these discoveries be used to help protect us against type 2 diabetes? Dr Yaghootkar is working with colleagues at the University of Westminster on a simple way to predict who is at risk of storing excess fat in the wrong place, which could take the form of a blood test to analyse someone’s genetic profile.
‘It’s a work in progress,’ she says. ‘But theoretically we could test young adults or even children to find out their diabetes risk.’ Experts at the University of Dundee are also looking to see whether they can use genetics not just to identify which people are at risk of type 2 diabetes, but sub-dividing those people into different groups.
These might include people who develop the disease before the age of 40 – known as early-onset type 2 diabetes – as well as those more likely to develop serious diabetes complications and those who might benefit from starting insulin treatment early.
Now I do 10,000 steps a day, even it’s running around the kitchen
Linda Bowyer has always made an effort to stay trim.
‘I’m only just over 5ft tall, so even a small amount of extra weight doesn’t look good on me,’ says the grandmother- of-six from County Durham.
‘My dinners have always been relatively healthy, mostly vegetables and meat, and rarely junk foods like chips.
Linda Bowyer has always made an effort to stay trim
‘And I’d run around after the grandkids at weekends and I did all the housework, running up and down stairs.’
So when a routine blood test in October 2020 indicated she was on the cusp of diabetes, she was shocked. ‘My blood sugar level was 47mmol/mol – one point below diabetic levels,’ says Linda, who weighed a healthy 8st 11 lb at the time. ‘I never expected it for one minute. I called my son and he said, “You can’t be!” ’
Linda’s GP referred her to WW, formerly Weight Watchers, as part of the NHS’s Healthier You NHS Diabetes Prevention Programme. She enrolled on a six-month programme with coaches trained in treating diabetes and improving blood sugar control.
Linda was advised to restrict sweets and eat smaller portions while upping her physical activity. She says: ‘I made small changes – I tried to do 10,000 steps every day, even if it was just running around the kitchen. I’d have one slice of wholemeal bread at lunch, instead of two slices of white. I switched to low-fat alternatives and made soups and salads.’
After six months Linda had lost more than half a stone – and her blood sugar was a healthy 33mmol/mol.
Today she has reintroduced a handful of sweets each week. ‘It’s worth cutting back to keep myself healthy,’ she adds.
But they also hope to use this information to work backwards, says the university’s Professor Ewan Pearson, to learn more about prediabetes and what makes some with the condition more likely to develop type 2 than others. While this type of genetic testing isn’t yet available, your waist size – rather than overall weight – is a good indicator as to whether you’re storing fat around and inside the abdomen.
Studies suggest a higher type 2 diabetes risk – and, therefore prediabetes risk – in women with a waist measurement of more than 31.5in, and men more than 37in.
For South Asian men, who are known to be more at risk at a lower weight, the measurement is 35in. People of Black Caribbean heritage are also more likely to develop prediabetes or diabetes – further evidence of the genetic causes.
A study by Professor Naveed Sattar, an expert in metabolic medicine from the University of Glasgow, found roughly one in six people from these ethnic groups had raised blood glucose levels compared with one in 30 white people.
Work led by Professor Roy Taylor at Newcastle University, as part of the wide-ranging DiRECT trial, has also found that most people have a personal ‘fat threshold’ – a danger point at which, regardless of their BMI, their body struggles to cope and blood glucose begins to rise.
‘That threshold could be at a BMI of 22 in some people, or 33 in others,’ says Professor Calum Sutherland, a diabetes expert at the University of Dundee. ‘But if you can identify it, you can tell people to stay below that number to prevent diabetes. ‘That will largely be genetically determined, but it’s complex and will also take in things like what you eat, how much you eat, how your gut works and how you metabolise food.’ At the moment, the best way to tell that you might be at risk of prediabetes is to look at your weight and whether anyone in your close family has developed type 2, experts say.
Diabetes UK’s Know Your Risk calculator – the details are on the following page – can help guide you. If the results show you may be high risk, you should ask your GP for a simple blood test that measures the amount of glucose in your blood. If you are obese, the prediabetes and type 2 diabetes risk remains clear.
There is another process at play: excess fat triggers the release of molecules called inflammatory cytokines by the immune system. In the long term, these proteins damage the insulin-producing cells in the pancreas.
Not only that, they dull the body’s response to insulin. So the amount that is produced becomes relatively useless – and that’s the start of type 2 diabetes.
Being overweight plus having diabetes genes may mean you develop the disease – or prediabetes – even earlier.
As Professor Jonathan Valabhji, the Government’s clinical director for obesity and diabetes, explains: ‘I’ve been practising as a doctor for 32 years now. I may have looked after a grandfather, diagnosed with type 2 aged 62, his daughter, diagnosed at 45, and now I might be looking after the granddaughter, diagnosed at 28. That’s what we’re seeing – it’s quite a common scenario, particularly in some South Asian and black communities where the risk of younger onset is a real issue now.
‘It’s not the genetic risk that has changed. But what has changed, over the past three or four decades, is the environment in which we live and populations gaining weight earlier. And this means a younger and younger age of type 2 onset.’
Dr Guess says: ‘We had very little type 2 diabetes in the 1930s compared with today, despite there being little change to our genetic make-up. We aren’t as active, we’re constantly advertised cheap food that’s high in calories, and we eat too much of it. That’s the really big problem.’
Despite this, it’s important not to lose heart. ‘It’s your weight and body fat that matters the most,’ explains Dr Bell.
‘If you’re overweight, it gives us a window of opportunity. If we can get in early and identify those most at risk, we can reduce their risk factors by supporting them to improve their diet and maintain a healthy weight.’
Super-fit… but ex-athlete Dion still got it at 39
Dion Howell is all too aware of the role genetics plays in developing diabetes.
A former athlete, the 41-year-old has always been a slim size eight, and prides herself on her healthy vegetarian diet.
Yet in March 2020, blood tests revealed a shock diagnosis: prediabetes.
‘I’d had Covid and I wasn’t feeling myself for nine weeks afterwards – I was exhausted – so the GP decided to do a load of blood tests,’ says Dion, from South London. ‘My blood sugars were strangely high. The doctors said I had prediabetes, but because I was otherwise healthy it must be genetic.’
Dion Howell is all too aware of the role genetics plays in developing diabetes. A former athlete, the 41-year-old has always been a slim size eight, and prides herself on her healthy vegetarian diet.
Sure enough, Dion’s mother, Evelyn, 78, had been diagnosed with type 2 diabetes the month before. ‘She hasn’t ever had a problem with her weight,’ says Dion.
The GP recommended Dion look at an online forum where fellow sufferers posted tips about how to bring down blood sugar levels.
Dion says: ‘The one thing that kept coming up was eating less porridge, because it gets converted to a lot of glucose in the blood. I’d eaten a big bowl every morning for as long as I can remember, so I halved the amount of oats. I also swapped sweets, which I ate most days, for strawberries and grapes.’
A three-month check-up found her blood sugar levels were in the normal range. ‘I upped my porridge a little bit after that,’ she adds, ‘but at the next check-up my sugars were up again – so it proves how sensitive I am to oats. I swapped porridge for toast and avocado.’
Dion’s latest blood test showed she was no longer prediabetic. She says: ‘I thought, if there’s something I can do to change this, no matter how tough, I have to do it.’