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.”

22nd November 2022 – By Aaruthy Suthahar

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. 

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.”

24th August 2022 – By Aaruthy Suthahar

TwinsUK researchers have found that your B cell and T cell responses are linked to COVID-19 infection.  

The immune system is made up of lots of different cells and organs that help your body fight off infections. B cells create antibodies, which neutralise viruses, with the help of T cells. Doctors and scientists have been using antibody tests to find people with previous COVID-19 infections, particularly for research. The TwinsUK team wanted to see if T-Cell tests would be a helpful addition, or replacement, for antibody tests. This is particularly important now many people cannot access PCR (swab) tests from the NHS when they think they have COVID-19.  

The study looked at T-cell responses in participants who did or did not have a positive antibody response to the virus that causes COVID-19 (SARS-CoV-2) in participants who were symptomatic and asymptomatic during the COVID-19 pandemic. 

The team gathered data from the TwinsUK cohort who participated in the home visit study and the COVID Symptom Study cohort. They were put into groups based on if they presented symptoms associated with COVID or not, and if they had taken part in TwinsUK’s antibody testing during the first wave in the UK in Spring 2020.  

There were 32 participants who were part of the final analysis. None of the 17 participants without antibodies showed a T cell response, when their blood was tested against peptides specific to the virus. 14 out of the 15 participants who had antibodies against COVID-19 experienced a T cell response.  Therefore, the study found that there was a strong correlation between antibody responses, and T cell responses to the peptides specific to SARS-CoV-2. Also, individuals who were symptomatic, but didn’t have antibodies after the infection wave in Spring 2020, had no proof of T cell memory of COVID-19 infection either. 

The researchers also found no evidence of cellular immunity suggestive of COVID-19 infection in individuals with COVID-19-like symptoms but negative antibodies. 

First author Dr Marc Österdahl said: 

“Now that access to COVID-19 PCR testing is restricted, it is important for the public, doctors and researchers to know how we can pick-up previous COVID-19 infection. The standard is IgG Spike antibody testing, but not everyone who had symptoms that looked like COVID-19 showed antibodies. 

We wanted to know if T-Cell testing, which is more expensive and complicated, would be needed to pick up all cases. However, in people who had symptoms in recent months, antibody and T-Cell responses are strongly linked, and T-Cell testing didn’t add any benefit. This suggests that the established IgG Spike test is best, and that symptoms in antibody negative people might be from another similar illness.”  

19th July 2022 – King’s College London

Changes that occur in the body in response to an increase in belly fat have been put under the microscope as part of a study from TwinsUK, offering new insight into the cause of metabolic disease.

The study, led by King’s College London researchers Dr Jordana Bell and Colette Christiansen and published in the medical journal Genome Medicine, looked at how epigenetic marks (measures of how the human body reads DNA to affect the way genes work) in fat tissue change as belly fat accumulates.

Using samples from 538 TwinsUK participants and combining genetic, gene function, diet, and health data, the researchers examined epigenetic marks across the genome (the complete set of a person’s genetic material) and found nine genes that are highly relevant to metabolic disease risk.

Among these was a gene where the identified epigenetic changes were recognised as a potential mechanism through which diet can affect belly fat accumulation, as well as other epigenetic marks that translate genetic risk effects on metabolic health.

The findings also allowed the researchers to characterise the molecular changes that occur because of an increase in belly fat and the impact these changes have on gene function and insulin resistance.

Dr Jordana Bell, reader in Epigenomics in the School of Life Course & Population Sciences said:

“With rapidly rising rates of obesity worldwide, it is important that we understand how elevated body fat affects us at the molecular level and how this translates to metabolic disease risk,”

Metabolic diseases – the most common of which is diabetes – disrupt normal metabolism or the process of converting food to energy on a cellular level.

While previous studies in this field have explored the role of epigenetic marks in overall obesity using body mass index (BMI), the build-up of belly fat deep within the abdomen is known to be a greater risk factor for metabolic disease than BMI alone.

Dr Jordana Bell added:

“Our study brings us one step closer to this goal by identifying an epigenetic signature of excess belly fat, understanding its genetic and dietary triggers, and characterising its functional impacts and clinical consequences for insulin resistance,”

Based on the results of the study, the researchers also developed an epigenetic predictor of insulin resistance, relating their findings to the clinical consequences of elevated belly fat.

Colette Christiansen, PhD researcher in the School of Life Course & Population Sciences said:

“It is exciting to see that when we combine many different layers of biological information, we can start to unravel the mechanisms which drive the state of our biological health.”

6th April 2022 – By Aaruthy Suthahar

New research has found that black tea and semi-skimmed milk are the most consumed items by TwinsUK members. The study, which aimed to understand eating patterns, also identified the top paired food items that were most consumed by twins were tomatoes and lettuce.

Researchers found that eating breakfast was not linked to an individual having a lesser or greater BMI (Body Mass Index) status or weight, even though they had a higher calorie intake. However, the team also found that individuals with a longer eating window were strongly associated with an increased BMI and weight. Diet has lots of complexities and variability, with a major effect on human health. It is not only what someone eats that can have ramifications for their health but also how and when. TwinsUK researchers have therefore been investigating the relationship between diet and disease. One key element is to understand individuals typical eating patterns and intake of nutrients. 

An EFR (Estimated Food Record) is a type of food questionnaire that allows researchers to understand eating behaviours in individuals by collecting data about all foods consumed in participants over a period. The open-ended style of an EFR means that it can more effectively identify how complex and variable individual diets are compared to methods which are more structured, including further understanding into, for example, eating patterns and of co-occurring foods.  

The researchers included 2,184 participants from our TwinsUK cohort between 2012 and 2017 and collected 2343 EFR’s from them. Twins were asked to provide information on the size of their portions, time of their meals, details of food type they consumed, date and a yes/no answer to whether they considered it a standard day’s intake. 

The team also found that twins who skipped their breakfast were reported to have a longer eating window than individuals who had breakfast, which could partly explain the lack of consistency in weight and BMI status between the individuals who had breakfast and those who skipped it. Also, time-restricted consumption, like consuming food daily within an 8-to-10-hour window, has been shown to improve glucose tolerance, although further research needs to be carried out in humans.  

One limitation of the research is that the study looked at data mostly from women. This means it is difficult to make an accurate conclusion without further clinical studies which include participants more representative of the diversity of the population in the UK.  

100 most frequently consumed food items, and food co-occurrence network of food pairings consumed within a food record; A 100 most frequently appearing word within food item descriptions, with the font size and colour depicting the importance of the food item B 100 most frequently appearing food item description