Amid the fragile optimism of early March, a new piece of research reminded us why obesity can be a serious health concern. Preliminary reports suggested those with obesity were suffering more severe Covid-19 outcomes. The World Obesity Federation published the data last month.
t determined the death rate from Covid was 10 times higher in countries where 50pc or more of the population is overweight and that 90pc of deaths occurred in countries with high prevalence of overweight. At the end of February, a non-peer reviewed Italian study suggested that immune response to the Pfizer jab may be less effective in those with obesity. Experts told the public not to be alarmed, and this is merely a case of reduced potency, rather than non-effectiveness.
“In so far as vaccines, in key respects, simulate infections at the molecular level, the findings of this study are of concern, and not surprising,” says Dr Brendan O’Shea, chair of the Clinical Advisory Group at the HSE/RCSI and a member of the National Programme For Obesity Working Group.
“Similar findings may emerge for others of the vaccines in due course, and this finding will almost certainly spark pharmaceutical companies to include and take account of diminished immunogenicity in overweight people in designing successive new generations of Covid-19 vaccines,” Dr O’Shea adds.
“It is almost certain that additional studies involving the other vaccines and how they work for people who are overweight are underway, and in time these studies will allow us to identify which vaccines work best for people who are overweight. So this is interesting, it is of some concern, but it’s important and it’s not all bad.”
The increased risk of developing additional illness due to obesity has been known about for some time. Now, there is renewed impetus for early intervention. In the UK, which has suffered the fifth highest fatalities globally, obesity has shot up the list of national priorities. Last month, a £100m package was announced to support state-level interventions.
This included £70m for weight management treatments and £30m to fund information services and upskilling for medical professionals. Among the incentives being considered are shopping vouchers, based on a similar scheme in Singapore where vouchers are linked to daily step counts. While Covid may have brought focus to the issue, those living with obesity generally suffer more serious disease and illness.
“What we know for sure is that obesity is associated with more severe symptoms and an increased risk of death with Covid. But this is not Covid-specific, this is the case with everything,” explains Dr Lydia Lynch, associate professor in immunology and biochemistry, and the founder of Trinity’s Lynch Lab which studies the relationship between the immune and metabolic systems.
“Obesity is associated with an increased risk of so many diseases, cancer, many infections, autoimmunity like multiple sclerosis psoriasis, rheumatoid arthritis. And it’s not just because of the increased weight, it’s because of the immune system.”
The nature of how obesity and being overweight affects the immune system is complex, but it does not require an individual to be obese for some of these processes to be activated. Dr Lynch adds: “Let’s say you’re on your way to becoming obese, eating maybe a high-fat diet, or eating a lot, or maybe your adipose tissues are expanding because you’re genetically predisposed to put on weight.
“As adipose tissue expands, each fat cell expands and expands to take on increased fat storage and then it can burst, which releases lipids, which is toxic to cells. So your immune system comes in to help clean up this toxic material, which triggers an immune response. That’s one form of inflammation.”
Dr Lynch explains that since the microbiome in those who are obese is less diverse than those who are not, the immune cells protecting the gut barrier are changed in obesity, which can lead to leaky gut, also triggering an immune response.
So the immune system is more stressed in patients with obesity and being overweight, but there are additional issues. For example, patients with obesity may suffer more serious infections, or more serious burns. Some patients with obesity can require double the amount of treatment to bring about the same results. In addition, if you’re obese you’re more likely to develop certain types of cancer.
“In endometrial cancer, half of the cases are due to obesity but 86pc of the population doesn’t realise there’s any link between obesity and cancer,” she says.
So, what is Ireland doing about obesity? The 2015 Healthy Ireland survey found that over 60pc of the population was overweight, with those living in deprived areas more likely to be obese. The sugar tax introduced in 2018 has seen some success in encouraging drinks and snack producers to “reformulate” their products, meaning to reduce the amount of sugar, or sometimes to reduce the size of the products.
When it came to treatment, however, there were gaps. Overweight patients were often basically pointed in the direction of their local slimming club due to poor availability of dietitian support.
In January 2020, the HSE identified overweight and obesity as one of its five strategic priorities in the intermediate term. Last month, the HSE’s National Clinical Programme For Obesity published its new model of care — a tiered-model which puts detection of weight issues and early intervention into a wraparound, community-led strategy.
“The balance of evidence is that whether we regard overweight and obesity as a disease or not, we should certainly be handling it as such,” says Dr O’Shea. “We should be clear about the diagnostic criteria and people should ideally understand the criteria.
“Doctors often assume that everybody knows to check their weight and how to do it properly. We did a study a few years back that was published in the Irish Medical Journal which asked around 200 people, ‘Have you got weighing scales and how do you use it?’
“What we found is that in this country where three quarters of adults are overweight, a third simply didn’t have weighing scales. Another third had weighing scales but either never used it or were using it incorrectly. And fewer than a third had weighing scales and were using it in a reasonable way.”
It is illustrative of where weight ranks in our priorities. “People think in a very woolly manner about this,” adds Dr O’Shea. “Part of our conversations in these years is to get a bit more precise because the benefits are significant.
“People who tend to check their weight accurately begin to do better, nearly straight away. It doesn’t sort out the problem, but you have little chance of stopping upward drift if you’re not checking.”
Other than a focus on detection and awareness, what has changed in the new model of care? For a start, it is very patient-centred and aims at enabling individuals with a care plan. Dr O’Shea says: “We pull in all of the aspects. The lifestyle coaching, the skill sets; to do a shopping list, to check your own weight, assisting people to access better exercise facilities.”
The tiered strategy is also, according to Dr O’Shea, substantially funded. “There’s a fairly large number of dietitians going in at the community level in a way that we didn’t have before. If I, as a GP wanted to send a patient entitled on the medical card to see a dietitian, the waiting lists typically would be anything from six to 18 months. That appointment would have been in a hospital in a town far away.
“There are an ongoing raft of breakthroughs on the pharmacological side. The last area where our system has been very deficient is in bariatric surgery. Our capacity for that has been shocking but the model of care clearly identifies this and the HSE is moving on it.”
Dr O’Shea says we are increasingly understanding the genetic and physiological components of obesity. That is helping to change the frame around obesity and reduce the stigma so we can treat it as another other condition.
This change is key, says Dr Lynch: “There’s not enough funding for obesity and looking after patients with obesity, because obesity is a chronic disease, just like all the other chronic diseases. Just saying, ‘Eat less’ doesn’t work. We really need to do something else. The big part that needs to happen is around the stigma of obesity. Once we get rid of that then we can think properly about the science.”
Ultimately, while the pandemic has thrown the lethal consequences of obesity into sharp relief, this may also become a once-in-a-generation opportunity to address a condition which it is far too easy to ignore.