Study Reveals Higher BMI Puts Adolescents at Risk for Depression 

5th September 2023 – By King’s College London

Children between the ages of 12 and 16 with a higher body mass index (BMI) are more susceptible to developing symptoms of depression, according to a recent study conducted by researchers from TwinsUK. The findings emphasize the importance of understanding the connection between mental health and weight in adolescence and suggest that early intervention strategies could be beneficial. 

The research, published in Psychological Medicine, used data from over 10,000 twins participating in the Twins Early Development Study (TEDS) and our TwinsUK cohort. Twins born between 1994 and 1996 self-reported depressive symptoms, including low mood, loneliness, and exhaustion, at ages 12, 16, and 21. The study’s key findings indicate a significant link between higher BMI and depression among individuals aged 12 to 16, with weaker association in the 16 to 21 age group. 

The team also found that children with a higher BMI during early adolescence were at an increased risk of developing depression later in life than those who experienced depression first and then saw an increase in their BMI.  

First author, Dr. Ellen Thompson explained: 

“Understanding the relationship between mental ill-health and weight in adolescence is vital to provide timely support where needed. This study shows a stronger association between having a higher BMI at age 12 years and subsequent depression symptoms at age 16 years than the reverse.” 

The study also highlighted that environmental factors played a significant role in the connection between BMI and depression at each age. While the study did not delve into the specific reasons for this effect, prior research has suggested that factors like body dissatisfaction and weight-related stigma from external sources could contribute to the association. 

Surprisingly, the study’s results remained consistent even after adjusting for socio-economic status, dispelling the notion from previous research that poverty might be the primary risk factor in this relationship. 

This shows the importance of early adolescence as a crucial period for addressing the potential consequences of higher BMI on mental health. Preventative measures, such as support structures and positive body image messages, could be incorporated into Personal, Social, Health and Economic (PSHE) education to counteract depressive symptoms in young teens. 

Co-senior author, Professor Claire Steves said: 

“Using the TwinsUK cohort, which focuses on older adult twins, our study showed that the relationship between BMI and depression was much weaker in later life. The exact reasons for these changes over the life course need further investigation.” 

Some people’s brain function still affected by Long COVID years after infection 

21st July 2023 – By King’s College London

Researchers from TwinsUK have found that people with longer-term COVID-19 symptoms including brain fog showed reduced performance in tasks testing different mental processes up to two years after infection with the virus.  

The team looked at whether infection with COVID-19 affected performance in two rounds of online cognitive testing that took place in 2021 and 2022. Data was collected for over 3,000 participants of the COVID Symptom Study Biobank study, across 12 tasks that tested memory, attention, reasoning, processing speed and motor control.  

The participants whose test scores were most affected by COVID-19 were those who had experienced symptoms related to the virus for 12 weeks or more. In these people, the effect of COVID-19 on test accuracy was comparable in size to the effect of a 10-year increase in age.  

There was no significant improvement in these test scores between the two rounds of testing, which took place nine months apart. By the second round of testing, the average time since participants’ initial COVID-19 infection was almost two years.  

Digging deeper into the analysis, the researchers separated participants by whether they felt fully recovered following COVID-19 infection. People who felt fully recovered after COVID-19 infection performed similarly to those who had not had the virus at all. In contrast, participants who did not feel fully recovered after infection had lower task accuracy scores on average.  

Lead author Dr Nathan Cheetham said: 

“Our findings suggest that, for people who were living with long-term symptoms after having COVID-19, the effects of the coronavirus on mental processes such as the ability to recall words and shapes are still detectable at an average of almost two years since their initial infection.  

“However, the result that COVID had no effect on performance in our tests for people who felt fully recovered, even if they’d had symptoms for several months and could be considered as experiencing ‘long COVID’, was good news. This study shows the need to monitor those people whose brain function is most affected by COVID-19, to see how their cognitive symptoms continue to develop and provide support towards recovery.”  

Professor Claire Steves added: 

“We used sensitive tests to measure speed and accuracy across a range of brain challenges. This study shows that some individuals have measurable changes in these tests after COVID-19 going on for nearly two years. The fact remains that two years on from their first infection, some people don’t feel fully recovered and their lives continue to be impacted by the long-term effects of the coronavirus. We need more work to understand why this is the case and what can be done to help.” 

Artificial Intelligence helps human radiologists: detecting intervertebral disc degeneration in MRI scans 

20th June 2023 – By Daliya Guemri

artificial intelligence

Researchers from TwinsUK have recently published a systematic review and meta-analysis examining the current efficacy of artificial intelligence (AI) machine learning applications that read MRI scans of degenerate discs. Working in the pain research team under Professor Frances Williams at King’s College London, researchers are motivated to glean the latest insights in developments to low back pain causes or treatment. Low back pain is the lead cause of disability globally and can fundamentally reduce patient quality of life. Intervertebral disc degeneration is a main cause of low back pain and Williams’ team is heavily invested in pioneering research into causes, diagnoses and treatments for the condition.  

Disc degeneration is a normal part of aging, however sometimes it is accompanied by disabling pain and interventions are required. This systematic review and meta-analysis specifically focused on machine learning (ML) algorithms that read lumbar magnetic resonance imaging (MRI) scans. Assessing disc degeneration is a time-consuming endeavour for radiologists, accurate machine learning algorithms that could fulfill this task, would represent a huge saving of work hours for health services across the globe. Fully exploiting AI technology could allow efficiency in identifying lumbar disc degeneration as well as other spinal conditions, and speed triaging patients for surgery or physiotherapy treatments.  

The systematic review found several studies with a computer science research focus that reported machine learning algorithms could do the job of radiologists, or that their approach could lead to diagnostic technology. Unfortunately, much of this software is not rigorously tested and most of the included studies had small numbers of participants. A systematic review and meta-analysis aim to the contribution of several small studies, however lack of replication (running the algorithm again in a totally new group of scans) was another stark omission from most of the included studies.   

In science, the best type of research is validated in different groups of participants and run multiple times. This should be a standard practice for medical treatments or tools. However they found that generally, these algorithms were not validated, and reports of added benefit to the assessment of disc degeneration were concluded perhaps prematurely.  

The technology is exciting as it does offer a real promise to the future of MRI reading and spinal assessments and ultimately better outcomes in patients with low back pain.  

Authors Roger Compte and Isabelle Granville Smith explained: 

We suggest future research should incorporate several machine learning approaches, such as adding semi- and un-supervised learning to supervised learning approaches. MRIs inherently contain vast quantities of information; of which the human eye is only capable of gleaning part. Designing machine learning algorithms that better take advantage of MRI data arrays may be a means to progress their reliability and accuracy to be comparable to and may one day surpass human radiologists.

Three types of long-COVID for people experiencing symptoms for 12 weeks or more 

17th April 2023 – By King’s College London 

Coronavirus

The paper recently published in Lancet Digital Health identifies patterns among people infected with the wild-type, the first strain of SARS-CoV-2, and Delta and Alpha variants, among vaccinated and unvaccinated individuals. 

Researchers from TwinsUK analysed data of 1,459 individuals who have experienced ongoing symptoms for longer than 84 days, known clinically as post-covid syndrome or long COVID, from the ZOE Health Study. 

The analysis adds to emerging evidence that long COVID is not a homogenous illness and should have personalised treatment and care. The team recommend the findings to be used by researchers investigating why and how long-COVID occurs, healthcare services providers, as well for people living with long COVID. 

People with symptoms for 12 weeks or more fell into three main groups based on the types of symptoms they were experiencing. The largest group was characterised by a cluster of neurological symptoms such as fatigue, brain-fog and headache and was the most common subtype among alpha and delta variants. A second group experienced respiratory symptoms including chest pain and severe shortness of breath, which could point to lung damage. This was the largest cluster in the wild-type period when the population was unvaccinated. Finally, there were some people who experienced a diverse range of symptoms including heart palpitations, muscle ache and pain, and changes in skin and hair. 

Crucially, the data also suggested that the symptom types for people who did experience symptoms for 12 weeks or more were similar in vaccinated and unvaccinated people at least with variants which had these data. Existing data shows that the risk of long-COVID overall is reduced by vaccination. 

Professor Claire Steves explained:  

These data show clearly that post COVID syndrome is not just one condition but appears to have at several subtypes. Our findings matched with people’s experience living with long COVID. Understanding the root causes of these subtypes may help in finding treatment strategies. Moreover, these data emphasise the need for Long-COVID services to incorporate a personalised approach sensitive to the issues of each individual.” 

While these three subtypes were evident in all variants, additional symptom clusters were also identified which were subtly different between variants. These differences may not be due to variants themselves, but other factors which have changed across the pandemic, such as time of year, social behaviours, and treatments. 

Given that the data used was collected over an interval of time, the study is relevant for post-COVID predictions, indicating how long certain symptoms could last. These insights could aid in the development of personalised diagnosis and treatment for these individuals. 

Diet high in protein linked with loss of muscle 

9th March 2023 – By Aaruthy Suthahar

beans and lentils

Researchers from TwinsUK have found that rather than being protective, high protein intake is associated with loss of muscle mass in healthy over-60s

This surprising finding comes from a study of 3,302 twins from the TwinsUK cohort. 

Sarcopenia is associated with ageing and occurs when there is an accelerated loss of skeletal muscle mass and function. This can lead to negative outcomes such as frailty, reduced function in day-to-day activities, and increased risk of falls. The study aimed to investigate factors linked with skeletal muscle strength, mass and sarcopenia, particularly intake of protein, and to evaluate if shared twin characteristics are important. 

The team studied twins who consumed the optimal recommended protein intake as the reference group (1.0–1.3 g/kg/day) and found that there was no significant link between protein intake (neither high nor low) and low muscle strength, or between low intake of protein and sarcopenia. 

Results showed that high protein intake on the other hand was associated with decreased muscle mass, while low protein intake was protective. High protein intake was also linked with sarcopenia, even after adjusting for demographic, anthropometric (physical measures of a person’s size, form, and functional capacities) and dietary factors. 

The study also found that the strength of muscles is linked with age, education, income, diet, appetite and diversity in the gut microbiome. However, the link between muscle strength and weight, body mass index, healthy eating index, protein intake, and gut microbiome diversity were not significantly influenced by shared twin factors. This means that treatments targeting these factors may be effective in preventing or treating sarcopenia. 

First author Dr Mary Ni Lochlainn explains: 

“We know high quality protein intake is essential for muscle health, however, it is important to consider that not all sources of protein contain the full range of essential amino acids, and that it may be important to eat some sources of protein in moderation.” 

“While our participants were healthy volunteers, the results give valuable insight into the link between diet and sarcopenia. Further research is needed to investigate this further, including looking at longitudinal data in cohorts with an increased number of participants who live with sarcopenia.” 

Can use of proton pump inhibitors increase your risk of fractures?

1st February 2023 – By Aaruthy Suthahar

Researchers from TwinsUK have found that taking proton pump inhibitors is linked with decreased hip bone density and this effect is partly mediated through plasma metabolites

This could put people at increased risk of fractures. 

Proton pump inhibitors (PPI) are common drugs used to treat gastric disorders and are one of the most used drugs in the UK. They decrease the release of acids in the stomach by blocking an enzyme which controls the production of acids. Acids in the gut microbiome are important for the absorption of a variety of nutrients like vitamins, iron, and calcium. Several studies have suggested that the use of PPI causes a lower absorption of intestinal calcium that could then lead to a decrease in bone mineral density (BMD) and increased fracture risk. 

The team wanted to investigate if PPI could modulate BMD by altering gut environment by using data from over 5,000 British male and female participants from the TwinsUK cohort.  

They observed a decrease in total hip BMD in individuals who used PPI. This effect however was not mediated through the gut microbiome, suggesting that the gut microbiome does not play a role in PPI’s effect on BMD.  

PPI users have lower plasma level of androgen sulfates, which belong to the sex hormone pathways. Besides, plasma androgen sulfate levels were associated with total hip BMD. Mediation analysis suggested that PPI could affect hip BMD indirectly through these plasma metabolites, providing a possible new mechanism.  

First author Xinyuan Zhang said: 

“In this study we showed that plasma metabolites could play a role in one of PPI’s major side effects, which is lowering BMD and increasing fracture risks. Our observation on the potential involvement of the androgen pathways in bone loss deserve additional investigations.” 

How much of a boost do “booster” COVID-19 jabs give?

26th January 2022 – By Aaruthy Suthahar

Scientists have found the “booster” COVID-19 vaccine programme led to a large boost in the antibodies that help protect against coronavirus. High levels of antibodies is associated with lower risk of severe infection.

The study, which is part of the National Core Study for Longitudinal Health and Wellbeing, is published today in the scientific journal eLife. Researchers from King’s College London, Bristol University, UCL and several other institutions around the UK teamed up to work on the project.

Researchers analysed blood samples from 9,361 participants from two UK population cohorts, with 4,739 participants from TwinsUK and 4,622 from Children of the 90s (also known as the Avon Longitudinal Study of Parents and Children). Samples were tested to measure antibodies generated by vaccination, and examine whether certain groups were more likely to have lower levels of antibodies. Lower levels are known to be linked to higher risk of coronavirus infection.

Similar to previous research, the study found higher infection rates among participants with lower levels of antibodies after a first vaccination. However, researchers also found large increases in antibodies with each round of vaccination. The level of antibodies was around 10 times higher in the first weeks after a third vaccine compared to those who had only received two vaccinations an average of six months earlier.

Some groups of individuals had consistently lower levels of antibodies after vaccination. In particular, people advised to “shield” in the first year of the COVID-19 pandemic because of an increased risk of complication due to COVID-19 were more likely to have fewer antibodies. The good news was that even these individuals mounted a strong response to the booster.

Researchers also found a third dose appeared to eliminate a key difference in antibody levels based on the type of vaccine received. While people who received the Oxford/AstraZeneca vaccine were more likely to have lower antibody levels than those who received Pfizer-BioNTech after one or two vaccinations, this difference was no longer present after a third vaccination.

Findings also showed people who had a confirmed coronavirus infection before vaccination were more likely to have higher levels of antibodies, compared to those without confirmed infection.

First author Dr Nathan Cheetham explained:

“ Our findings support a policy of a third (and now fourth) COVID-19 vaccination to boost antibodies and protect against COVID-19. This is especially true for people who had the Oxford/AstraZeneca vaccine for their first and second jabs. ”

“ Our results also showed that some people are more likely to have a weaker response to vaccination than others, which we hope will be useful for policy-makers when considering any future COVID-19 vaccinations. In particular, we saw in participants from both TwinsUK and Children of the 90s cohorts that the “Shielded Patient List” criteria were an effective means to identify those with lower response to vaccination, despite the guidance to shield no longer being in place. ”

Professor Claire Steves said:

“We were particularly pleased to see that individuals at higher risk of severe infection still responded well to the booster vaccination. This is further evidence that coming forward for a booster vaccination is a good idea as COVID is still very much around.”

What does your X chromosome say about your risk of chronic disease?

22nd November 2022 – By Aaruthy Suthahar

Human chromosomes, 3D illustration. Science and medicine background

Your X chromosome contains clues as to whether or not you might develop cancer and heart disease, according to latest research from TwinsUK. 

Chromosomes are lengths of DNA that contain genes on them. Human males have both an X and a Y chromosome, and females have two X chromosomes (XX). We only need one dose of the genes on the X chromosome, so in females, one of the X chromosomes in every cell is switched off so they do not get double the dose. 

This process of X-inactivation is meant to happen at random, but researchers have identified that in some people as they age, one X is more likely to be inactivated than the other. In this study, the team identified that skew in X-inactivation (XCI) is associated with chronic health outcomes. They found that XCI-skew in older females can pick up on changes that occur in a population of blood cells and can be used as a potential biomarker to recognise the risk of developing chronic conditions.  

Ageing is a complex process that involves different cellular and molecular features, which includes alteration to blood cells and makes an individual more susceptible to developing chronic conditions.  

The team studied 1,575 female TwinsUK members to examine XCI skew and its link with ageing, risk of developing heart disease, and cancer diagnoses.  

Researchers also found that XCI-skew is linked with the number of years an individual has lived and increases over someone’s life span. The changes in the frequency of XCI-skew were examined across increasing ages and identified 12% of participants below 40 years old displaying XCI-skew, 28% of 40–59-year old’s; 37% of 60–69-year old’s; and 44% of those over 70-year-old. 

Furthermore, results showed that a skewed XCI can predict future cancer detection in a 10-year follow-up. They found that using a heart disease risk score, picked up on specific risk factors, and can predict the risk of a major heart disease event in the next 10 years, with a heart disease risk score greater than 7.5% characterizing an intermediate-risk, and a heart disease risk score greater than 20% characterizing substantial risk. 

A limitation of the study was that the sample sizes restricted the chances of carrying out investigations on specific deaths or cancer types. 

First author Dr Amy Roberts explained: 

“This study provides a better understanding of the link between X chromosome inactivation and our health and might help explain why some twins develop chronic diseases even if their co-twin does not. Further research is needed to convert the biological usefulness of skewed XCI into clinical applications for investigating the link between blood cell changes as someone ages and association with chronic disease, despite chromosomal sex.” 

This paper is part of a broader programme of work investigating how the X chromosome affects our health. 

Under pressure: The link between belly fat, blood pressure and food responses revealed

26th October 2022 – By Paz García

Red cartoon heart underneath a semicircle of dots going from green on the left side to red on the right side. A dial from the heart is pointing towards the red side.

In a world first, a team of researchers led by TwinsUK has found that people with high blood pressure take longer and work harder to clear fats from the blood after meals and have higher levels of inflammation after eating. 

The research, published today in Nutrients, identified that this link is in large part due to visceral fat – the kind that wraps around your organs in your belly. 

This suggests that reducing belly fat could be particularly important in improving the body’s responses to food in people with high blood pressure. 

First author and TwinsUK researcher Panayiotis Louca said: 

“People with high blood pressure are more likely to have higher levels of visceral fat than people with normal blood pressure. Our study found that this visceral fat is indeed responsible for a considerable amount of the difference we see in blood fats and insulin levels between these two groups after meals.” 

The research was part of ongoing analysis of data collected during the PREDICT study, where 1,000 participants – including several hundred TwinsUK members – had their bodies’ responses to food measured over a two-week period. 

Previous studies have shown that people with high blood pressure have higher baseline levels of blood fats, insulin and inflammation compared with people with normal blood pressure, and higher blood fats following a fatty meal. The present study however was the first to investigate and compare responses between the two groups following a nutritionally balanced meal. 

Senior author and TwinsUK researcher Dr Cristina Menni said: 

“We’d like to thank all of the participants who spent a full day in clinic and then two weeks meticulously logging their meals and collecting blood samples at home. It’s because of your dedication that we are able to advance health research.” 

Louca et al. Postprandial responses to a standardised meal in hypertension: the mediatory role of visceral fat mass. Nutrients 2022

Experiencing symptoms of COVID-19 associated with poorer mental health

14th October 2022 – By King’s College London

Having symptoms of COVID-19 has been associated with worse mental health and lower life satisfaction.

The study, which is part of the COVID-19 Longitudinal Health and Wellbeing National Core Study, is published today in The Lancet Psychiatry. It is led by researchers from King’s and University College London in collaboration with several UK institutions. 

Data was taken from 11 longitudinal studies between April 2020 and April 2021, in which there were 54,442 participants with and without self-reported COVID-19. The study looked at the impact of COVID-19 infection on subsequent mental health and well-being.

Researchers found that rises in psychological distress, depression, anxiety, and lower life satisfaction were associated with prior self-reported COVID-19. The associations with poorer mental health did not lessen over time after infection, highlighting the potential enduring impacts of the disease and the need for a longer follow-up process from healthcare providers.

Self-reported COVID-19 was consistently associated with psychological distress, regardless of whether people tested positive for antibodies to the virus. These effects of infection were felt similarly in different groups of gender, ethnicity, and socio-economic circumstances.

The study suggests that the infection of COVID-19 might impact mental health most in older people as people with self-reported infection aged 50 years and older showed a stronger association with poorer mental health. This might reflect that older people are more likely to experience more severe COVID-19 symptoms, greater worry around infection, and increased risk of blood vessel (microvascular) or brain (neurological) changes after infection. This contrasts with the effect of the pandemic overall on mental health, where previous studies have shown that women and adults aged 25-44 have had the greatest adverse impacts.

Joint first author Dr Ellen Thompson from The School of Life Course & Population Sciences said:

“These findings suggest that there were prolonged mental health consequences of COVID-19 infection for some people at the beginning of this pandemic. Understanding why this is the case will be key to finding treatment strategies for those affected as well as preventing such effects in future pandemic waves.”

Senior author Prof Praveetha Patalay from University College London said:

“This study brings together many of the UK’s longitudinal studies to provide a comprehensive overview of the impacts of COVID-19 infection on population mental health. Compared to most studies to-date that have focussed on more severe and hospitalised cases, this study demonstrates the impact of infection during a pandemic on overall population mental health and wellbeing.”

Recent Blog Post

Study Reveals Higher BMI Puts Adolescents at Risk for Depression 

14th October 2022 - By King's College London Having symptoms of COVID-19 has been associated with worse mental health and...

Diversity at TwinsUK: Genevieve

14th October 2022 - By King's College London Having symptoms of COVID-19 has been associated with worse mental health and...

Diversity at TwinsUK: Bridget

14th October 2022 - By King's College London Having symptoms of COVID-19 has been associated with worse mental health and...