Global -Disease -Prevalence _V3(1)

In November last year we discussed how the global health landscape is changing, due to advancements in technology and care, and the fact that we’re now living for longer.

We examined the present-day prevalence of a handful of conditions, some of which are among the world’s biggest killers, including heart disease, diabetes and malaria; and using a range of reports and studies, we attempted to gauge how common experts think these conditions will be in the decades to come.

In this, the second in a series of posts on this topic, we’ll be continuing what we started. We’re turning our attention more particularly this time to chronic conditions, including allergies, asthma, arthritis, psoriasis and osteoporosis.

Once again, we’ll look at how common scientists expect these conditions to be midway through the 21st Century, some of the factors behind these projections and, where possible, how treatment may develop in the immediate future.

How common will allergies be in 2050?

Experts believe that the overall prevalence of some allergic conditions is set to rise; and for people living in certain parts of the world, environmental factors may increase the severity of symptoms that those with allergies experience.

One study published in 2016 examined how the increasing presence of ragweed in Europe is expected to contribute towards a significant upsurge in both pollen concentration and airborne latency on the continent. This, they noted, would see the number of Europeans affected by sensitivity to ragweed rise: from 33 million today; to 77 million at some point between 2041 and 2060.

The study explains that for those with ragweed allergies living in Hungary and in the Balkan region, sensitivity symptoms (which include nasal congestion, sneezing, headaches and irritation in the throat and eyes) will rise; but the actual number of people susceptible to ragweed sensitivity will see its largest proportional increase in Northern European nations, such as France, Germany and Poland.

Figures from other organisations concur that a rise in allergy prevalence is imminent. A statement by the European Commission in 2010 estimated that, by 2050, around 50% of people living in the EU would have an allergic condition (compared with 35% back then).

Elsewhere, findings reported to the American College of Allergy, Asthma and Immunology in 2012 stated that pollen levels were expected to increase by 1.5 to two times their current levels in the US. The research stopped short of saying that an overall increase in allergy symptoms would be a foregone consequence of this, but stated that those with allergies could take action now by exploring immunotherapy treatment options.

Globally, allergic diseases are thought to affect one billion people currently. However, this is expected to rise to around four billion by 2050 (by this time, 4 billion will constitute just over 40% of the world’s 9.7 billion population).

Food allergies and anaphylaxis

However, other types of allergies, not related to pollen, are thought to be on the increase too.

A UK study in 2007 noted that, since 1990, there had been a five-fold increase in hospital admissions due to food allergies, and a seven-fold increase in those due to anaphylactic reactions. Allergy UK reports that the number of hospitalisations for anaphylactic reactions between 2011-2 and 2015-6 increased in the UK by 19 percent.

Several factors are thought to be behind this trend. One consultant allergist noted in The Guardian that increased overall awareness is leading to a higher rate of diagnoses; but also that our lifestyles and diets, due to the way they influence our exposure to certain allergens, might be having an impact too.

Many new-onset cases of food allergies now develop in adulthood, opposed to early on in life. One theory put forward is that exposure to a certain type of food through unusual means can lead to late-onset sensitisation.

An example used in the above Guardian article by Tina Dixon, a consultant allergist based in Liverpool, is that of a chef she treats with a late-onset egg allergy. By breathing in and absorbing particles of egg over a long period, she theorises that the patient has developed a hypersensitivity to it.

How will treatment evolve?

The good news for those with allergies is that, as we come to better understand these conditions, allergy treatments will likely improve. For allergic rhinitis, researchers are currently investigating the efficacy of co-administering more than one treatment at a time. Low dose UVB is also an option being explored.

One piece of research suggested that sublingual administration of epinephrine in tablet form for anaphylactic patients may offer a more convenient alternative to the solution contained in injector pens (it theorised that tablets may be preferable for the needle-phobic, and that these wouldn’t need to be replaced as often as they would be less susceptible to degradation than the injectible solution). However testing for this form of epinephrine delivery is still in an early phase.

How common will asthma be in 2050?

There are conflicting estimates of how prevalent asthma will be in the future.

Asthma UK reports that, in the UK, one in 11 people (or 5.4 million) are currently affected by the condition. However, they also state that the rate of increase has seemingly levelled off since the late 1990s.

(The number of people who have ever been diagnosed with asthma is higher at around 8 million; however many who are diagnosed with asthma during childhood ‘outgrow’ the condition, so the number of people with active asthma is smaller.)

Rises in asthma prevalence are also expected in the US. Some estimate a rise of 36 percent (from 40.8 million to 55.8 million) in lifetime asthma patients by 2050.

The European Academy of Allergy and Clinical Immunology estimated in 2014 that asthma would be the most common chronic childhood illness by the year 2025. They cited the increase in prevalence in urban areas, mainly due to lifestyle and environmental factors, as the leading proponent in this rise.

So what are some of these environmental factors?

Indoor air pollution is one.

In 2015, one professor from Reading University said that energy efficiency in households essentially traps in exacerbating airborne pollutants from cooking, cleaning and applying cosmetics. Because more and more households are being built with energy efficiency in mind, he estimated this would lead to an 80% rise in asthma prevalence by 2050 (this would take the current affected population of the UK from 5.4 million to 9.7 million).

It’s perhaps unsurprising then given these projections that asthma prevalence is also expected to increase globally.

In 2007, the World Health Organisation stated that an estimated 300 million people worldwide were living with asthma, and that this would increase to at least 400 million by 2025.

According to an entry in the World Allergy Organisation Journal, asthma will affect 10%, or roughly a billion, of the world’s population by 2050.

How will treatment evolve?

It’s difficult to say. At present, it doesn’t seem as though an absolute cure for asthma will be discovered imminently. As with allergies, ongoing research is being undertaken to better understand the condition and what causes it. This will help scientists develop new ways to help patients manage the condition and keep attacks to a minimum.

A paper in the European Respiratory Review said on the subject that investigations into new ways of targeting the condition showed promise, and may have the potential to ‘cure mild asthma, and considerably improve the control and quality of life of the most severe patients.’

For instance, developing methods of isolating and stopping the IgE molecule (which triggers allergic asthmatic episodes) from being reproduced in the body is one such approach researchers are looking into.

One other theory is that allergic asthma is a reaction to a parasite which the immune system thinks is present, but is not; and therefore treatments in some way derived from parasitic worms may hold the key to lessening symptoms.

How common will arthritis be in 2050?

Osteoarthritis (where the joints in the body sustain progressive damage over time) is also set to rise in the coming years, and this is largely due to the expected increase in the ageing population.

In the UK, Arthritis Research states that 8.75 million people have sought treatment for osteoarthritis:

  • 4.33 million of this population are aged between 45 and 64;
  • 2.15 million are aged between 65 and 74;
  • and 2.27 million are over the age of 75.

These figures constitute one third of people aged 45 and over; and just under half of those aged 75 and over.

The CDC reports that between 2010 and 2012, there were 52.5 million adults living in the US who had been diagnosed at some point with an arthritic condition; these included osteoarthritis, rheumatoid arthritis, lupus, gout and fibromyalgia. 30.3% of US adults aged 45-64 had received a diagnosis of some sort of arthritic condition, as had around half of persons over the age of 65.

According to a Canadian review of figures, total prevalence rates for osteoarthritis in Australia and Northern European countries such as Belgium, Norway and the Netherlands, ranged between 8% and 13%; which seems comparable to those in the UK (12.5%). However, diagnosis rates in southern Asian countries are lower (between 4 and 11%), and lower still in South American and the Middle-Eastern countries (between 2 and 4%).

Determining global prevalence for arthritis then is tricky; different countries have varying definitions of arthritic conditions, and it might be possible that symptoms potentially being underreported by patients may be a contributing factor behind the comparatively low diagnosis rates in South America and the Middle East.

We can deduce from the increasing average age of the population that the prevalence of osteoarthritis is going to rise; but to get an idea of how much it is going to rise by, it might be useful to look a 2007 study from Australia.

10 years ago, Arthritis Australia stated that 3.85 million Australians were living with some form of arthritis at that time. They cited research from Access Economics that by 2050 this number would have risen to 7 million.

If we use these projections for Australia (which has similar prevalence rates to the UK and other countries in Northern Europe) as a template, that would mean the prevalence of arthritic conditions would be set to almost double from their 2007 levels by 2050. For the UK, this would mean the number of people affected rising from 8.75 million to around 15-17 million.

One other US projection from 2007 forecasted a slightly less drastic but still significant upsurge, estimating that the number of adults in the US living with arthritis would rise from a 2005 total of 60 million to 96 million by 2050, which would constitute a 1.6-fold increase.

How will treatment evolve?

The causes of rheumatoid arthritis are thought to be both genetic and environmental in nature, and research aiming to better identify these is ongoing. Once more, a better understanding will help scientists to develop new treatments.

For osteoarthritis, there are several different options currently being explored. These include tissue regeneration technology, which could help to reform damaged bone and cartilage in affected joints. Another treatment method scientists are attempting to harness for osteoarthritis is nanotechnology; more specifically, nanoparticle injections which would be administered to a joint shortly after an injury to reduce inflammation, and limit degeneration.

How common will psoriasis be in 2050?

Psoriasis is an autoimmune disorder which, according to the NHS, affects two out of every 100 people in the UK. Globally, it is estimated to affect 120 million people.

However, determining trends for this condition is problematic, as prevalence data from previous years is sparse.

A 2016 report by WHO suggested that, from the limited data available, we can ascertain that psoriasis is becoming more commonly diagnosed:

  • they noted that prevalence in China rose from 0.17% in 1984 to 0.59% in 1999;
  • in Spain, it rose from 1.43% in 1998 to 2.31% in 2013;
  • and that in the US, prevalence rose from 1.62% in 2004 to 3.1% in 2010.

Furthermore, as it is a condition more commonly diagnosed in older adults, the ageing global population is also expected to have an impact on overall prevalence in the coming decades. Increased awareness of the condition is also no doubt having an impact on the rate of diagnoses.

So while we cannot put a figure on the number of cases there may be in 2050, it is likely that there will be more known cases in the future than there are today.

How will treatment evolve?

Relatively little is known about why psoriasis develops. However new drugs for the management of psoriatic conditions are in development.

Two such examples, which are IL-17A and IL-23 inhibitors, work by stopping proteins from producing an anti-inflammatory response in the body. A spokesperson for the National Psoriasis Foundation Medical Board noted that these types of medication are promising due to their ‘very high response rates’.

How common will osteoporosis be in 2050?

Currently, there are thought to be 3 million people living with osteoporosis in the UK. The NHS notes that there are half a million hospital admissions in Britain for fragility fractures related to osteoporosis on an annual basis.

Worldwide, the International Osteoporosis Foundation estimates that there are 200 million people affected by the condition, and 30 percent of all postmenopausal women in the US and Europe have osteoporosis. Globally, there are 8.9 million fractures related to osteoporosis each year.

Once more, the ageing population is likely to cause an upsurge in prevalence in the coming years. Hip fractures in men are expected by the IOF to increase by 310% on their 1990 levels by 2050; and by 240% on their 1990 levels in women.

How will treatment evolve?

It goes without saying that the more we learn about osteoporosis and the better we understand the condition, the more action people as a whole will be able to take to prevent it. Calcium and vitamin D are vital in offsetting the development of osteoporosis, so a diet containing a healthy amount of these nutrients is essential. Undertaking regular exercise plays an important role in reducing risk too.

Several different types of treatment for osteoporosis are currently available. Some work to lessen the rate at which bone density breaks down over time, and others work by redressing hormone levels (a hormonal imbalance is often a cause of bone density reduction).

Research into treatments which work specifically on bone cell pathophysiology is underway. A Swiss paper from 2012 discussed how new treatments may target specific molecules which regulate bone cell function. It is also hoped that more advanced diagnostic tools, which help doctors to identify precursive bone degeneration patterns in adolescence and adulthood, may also enable preventative treatment to be initiated earlier.

Once more, we’ll be returning to discuss this topic further in the coming weeks. In the meantime, you can stay up to date with all the latest posts by following us on @Treated_com