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Type two diabetes accelerates brain ageing and cognitive decline
Scientists have proven that normal brain ageing is accelerated by about 26 per cent in people with progressive type two diabetes.
The authors of a study published on May 24 in eLife, evaluated the relationship between typical brain ageing and that seen in type two diabetes.
They observed that type two diabetes follows a similar pattern of neurodegeneration as ageing, but progresses faster.
One important implication of this finding is that even typical brain ageing may reflect changes in the brain’s regulation of glucose by insulin.
The results further suggest that by the time type two diabetes is formally diagnosed, there may already be significant structural damage to the brain.
Sensitive ways to detect diabetes-associated changes to the brain are therefore urgently needed.
Difficulties
There is already strong evidence linking type two diabetes with cognitive decline, yet few patients currently undergo a comprehensive cognitive assessment as part of their clinical care.
It can be difficult to distinguish between normal brain ageing that begins in middle age, and brain ageing caused or accelerated by diabetes.
To date, no studies have directly compared neurological changes in healthy people over the course of their lifespan with changes to those experienced by people of the same age with diabetes.
“Routine clinical assessments for diagnosing diabetes typically focus on blood glucose, insulin levels and body mass percentage,” says first author Botond Antal, a PhD student at the Department of Biomedical Engineering, Stony Brook University, New York, US.
“However, the neurological effects of type two diabetes may reveal themselves many years before they can be detected by standard measures, so by the time type two diabetes is diagnosed by conventional tests, patients may have already sustained irreversible brain damage.”
The study
To define the impact of diabetes on the brain over and above normal ageing, the team made use of the largest available brain structure and function dataset across human lifespan: UK Biobank data from 20,000 people aged 50 to 80 years old.
This dataset includes brain scans and brain function measurements and holds data for both healthy individuals and those with a type two diabetes diagnosis.
They used this to determine which brain and cognitive changes are specific to diabetes, rather than just ageing, and then confirmed these results by comparing them with a meta-analysis of nearly 100 other studies.
Their analysis showed that both ageing and type two diabetes cause changes in executive functions such as working memory, learning and flexible thinking, and changes in brain processing speed.
However, people with diabetes had a further 13.1 per cent decrease in executive function beyond age-related effects, and their processing speed decreased by a further 6.7 per cent compared to people of the same age without diabetes.
Their meta-analysis of other studies also confirmed this finding: people with type two diabetes had consistently and markedly lower cognitive performance compared to healthy individuals who were the same age and similarly educated.
MRI scans
The team also compared brain structure and activity between people with and without diabetes using MRI scans.
Here, they found a decrease in grey brain matter with age, mostly in a region called the ventral striatum – which is critical to the brain’s executive functions.
Yet people with diabetes had even more pronounced decreases in grey matter beyond the typical age-related effects – a further 6.2 per cent decrease in grey matter in the ventral striatum, but also loss of grey matter in other regions, compared with normal ageing.
Together, the results suggest that the patterns of type two diabetes-related neurodegeneration strongly overlap with those of normal ageing, but that neurodegeneration is accelerated.
These effects on brain function were more severe with increased duration of diabetes. In fact, researchers linked progression of diabetes to a 26 per cent acceleration of brain ageing.
“Our findings suggest that type two diabetes and its progression may be associated with accelerated brain ageing, potentially due to compromised energy availability causing significant changes to brain structure and function,” concluded senior author Lilianne Mujica-Parodi, Director of the Laboratory for Computational Neurodiagnostics, Stony Brook University.
“By the time diabetes is formally diagnosed, this damage may already have occurred.
“But brain imaging could provide a clinically valuable metric for identifying and monitoring these neurocognitive effects associated with diabetes.
“Our results underscore the need for research into brain-based biomarkers for type 2 diabetes and treatment strategies that specifically target its neurocognitive effects.”
Gut-friendly foods such as kimchi and kombucha may carry hidden risks for heart health when eaten in excess, the British Heart Foundation (BHF) has warned.
The charity said foods marketed as prebiotic, probiotic or otherwise good for the gut can support the microbiome, but some may also be high in salt or sugar, which can raise the risk of cardiovascular disease.
Products highlighted by the British Heart Foundation included kimchi, kombucha, fruit yoghurts, smoothies and sauerkraut. It said there is no harm in including them as part of a healthy diet, but advised people to check labels for added salt and sugar and eat them in moderation.
Tracy Parker, the charity’s nutrition lead, said: “We encourage everyone to choose foods that can keep their gut microbiome healthy. The benefits are clear, and we are continuing to improve our understanding of how a gut-friendly diet may help our hearts.
“A lot of these products can contain high levels of salt or sugar though, so it is important to be aware of the potential drawbacks.
“By ensuring you check package labels for added salt and sugars, and eat each in moderation, you can make sure the risks do not outweigh the benefits for your heart health.”
Fermented foods such as kimchi and sauerkraut are rich in probiotics, the healthy bacteria produced during fermentation that can help support a diverse and healthy gut microbiome.
However, both are traditionally made using a lot of salt, which can raise blood pressure if eaten frequently or in large quantities. High blood pressure is known to increase the risk of heart attack and stroke.
Kombucha, a fermented tea, also contains probiotics and can be a healthier alternative to fizzy drinks, but many commercial and shop-bought versions contain added sugar.
Eating too much sugar can lead to weight gain, which can increase the risk of heart attack, stroke and other cardiovascular disease.
Fruit yoghurts can contain probiotic live bacteria cultures, but may also be high in sugar and have fewer live cultures than plain versions.
The charity said plain yoghurt with live and active cultures on the label can be a lower-sugar option, with whole fruit added at home for sweetness.
Smoothies made with whole fruits provide prebiotic fibre, which feeds beneficial gut bacteria and supports digestive health.
They can also provide vitamins and antioxidants, especially when made with a variety of plant-based ingredients.
But blending breaks down the structure of fruit, releasing free sugars that behave like added sugars in the body and can cause faster rises in blood sugar levels.
Regularly consuming too much sugar can lead to weight gain, which can increase the risk of developing type 2 diabetes, heart disease and kidney disease.
The charity said only one 150ml serving of any smoothie counts towards five-a-day, and suggested adding nuts or seeds for extra protein and fibre to help keep blood sugar levels more stable.
The BHF also noted that some shop-bought sauerkraut is pasteurised, which removes most of the live bacteria.
It advised checking the label, eating small portions and choosing unpasteurised products for those seeking the probiotic benefits.
The charity said beneficial gut bacteria produce short-chain fatty acids during digestion, which are linked to reduced inflammation, better metabolism and better heart and circulatory health.
These good bacteria also help digest polyphenols, natural plant chemicals thought to have antioxidant properties and which may help lower blood pressure.
By contrast, harmful gut bacteria, which thrive on diets high in fat and red meat, produce chemicals that can cause problems in the heart and blood vessels by increasing inflammation and altering how cholesterol is processed in the body.
Beneficial bacteria thrive on varied diets high in prebiotics, non-digestible fibres found in foods such as wholegrains, oats, beans, lentils, bananas and onions.
People with diabetes may have undiagnosed heart failure that could be detected by a simple screening blood test, research suggests.
The TARTAN-HF trial found that one in four patients with diabetes who had at least one other risk factor for heart failure had undiagnosed heart failure detected through screening with a blood test and ultrasound scanning of the heart.
Experts said the findings show the extent of unrecognised heart failure in people with diabetes, and how the condition can be detected using a widely available blood test called NT-proBNP, which measures how much strain the heart is under.
They suggest a heart failure screening programme for diabetics could improve diagnosis rates, lead to earlier treatment and potentially reduce the risk of hospitalisation and death.
The study, involving 700 patients, was led by the University of Glasgow in collaboration with AstraZeneca, Roche Diagnostics, Us2.ai, NHS Greater Glasgow and Clyde and NHS Lanarkshire.
Dr Kieran Docherty, clinical senior lecturer at the University of Glasgow’s School of Cardiovascular and Metabolic Health, said: “Our results from the landmark TARTAN-HF trial identified heart failure in a large proportion of people living with diabetes, emphasising the need for a heart failure screening strategy in this group of patients.
“We know that many of the symptoms and signs of heart failure are non-specific, and may go unrecognised as potentially being due to heart failure for a long time.
“The strategy used in our trial is simple and easy to implement in clinical practice, and will aid in the early identification of heart failure in people with diabetes, and facilitate the initiation of medications that we know improve outcomes in patients with heart failure.”
The study, which began more than three years ago, involved more than 700 people with diabetes from the two health board areas who had at least one other risk factor for heart failure.
They were randomly assigned either to receive heart failure screening or to continue with their usual care.
Researchers found screening uncovered a large number of previously unrecognised cases of heart failure. Around one in four, or 24.9 per cent, of those screened were found to have the condition within six months, compared with 1 per cent in the group continuing their usual care.
The study, involving patients with type 1 and type 2 diabetes, found almost all of the participants found to have heart failure had preserved ejection fraction, which can be difficult to detect without dedicated testing.
The findings of the TARTAN-HF trial were presented at the American College of Cardiology conference taking place from 28 to 30 March in New Orleans in the US.
Dr Edward Piper, medical director at AstraZeneca UK, said: “Delayed diagnosis and treatment of heart failure in people with type 2 diabetes contributes to poor long-term outcomes. TARTAN-HF demonstrates that targeted, risk-based screening can identify previously undiagnosed heart failure in approximately one in four high-risk patients with diabetes, enabling earlier intervention with guideline-directed therapy.”
Dr Christian Simon, head of global medical affairs at Roche Diagnostics, said: “We are proud to have supported the landmark TARTAN-HF trial. These findings demonstrate the transformative power of early, accessible diagnostics like the NT-proBNP blood test.
“By identifying unrecognised heart failure in people with diabetes, we enable clinicians to initiate appropriate treatments sooner, ultimately improving patient outcomes and lives.”
The UK has launched a £6.3m men’s health fund to back local projects aimed at helping men and boys live longer, healthier lives.
The Men’s Health Community Fund is a partnership between the Department of Health and Social Care, Movember and People’s Health Trust.
The government is contributing £3m, while the two charities are more than doubling that to take the total to £6.3m.
Grants will support community projects reaching underserved men and boys aged 16 and over, particularly in the most disadvantaged areas and at key points in their lives such as becoming a father, losing a job or retiring.
Projects could include support for new fathers, activities for men facing loneliness and social isolation, services to help young men engage with the health system, and support for men in work, out of work and moving into retirement.
The programme will bring together voluntary, community and social enterprise organisations to test new ways of reaching men who are least likely to use traditional health services.
An evaluation funded through the National Institute for Health and Care Research will assess what works and help inform future policy and delivery.
Health and social care secretary Wes Streeting said: “Too many men across the country are living shorter, less healthy lives, particularly those in our most disadvantaged communities.
“This new partnership will help men get the support they need in the places they feel most comfortable, their communities, among people they trust.
“By working with expert charities and local organisations, we can reach the men who are too often missed by traditional services and help them take better care of their mental and physical health.”
“It is a key step in delivering our first ever Men’s Health Strategy and driving forward our ambition to halve the gap in healthy life expectancy between the richest and poorest areas.”
The Men’s Health Strategy sets out plans to tackle the physical and mental health challenges men and boys face.
Men can be less likely to seek help and more likely to suffer in silence, while higher rates of smoking, drinking, gambling and drug use are damaging men’s health and affecting families, workplaces and communities.
The government is also investing £3.6m over the next three years in suicide prevention projects for middle-aged men in local communities across areas of England where men are most at risk, many of which are also among the most deprived. Suicide is one of the biggest killers of men under 50, and three-quarters of all suicides are men.
The projects will aim to break down barriers middle-aged men face in seeking support, including stigma around asking for help and a lack of awareness of what is available and how to access it.
They will be co-designed with experts and men with lived experience of mental health crises and suicidal thoughts.
Gut-friendly foods may damage heart, charity warns
Diabetes patients face increased risk of undiagnosed heart failure
UK government announces £6.3m fund to boost men’s health
Brain health collaboratory launches in Gulf South
