There are certainly side-effects and shared conditions that make diabetics more vulnerable – but the real Covid-related threat to diabetics may well be lockdown weight gain
Saturday 14th November 2020 was World Diabetes Day. It is the birthday of Sir Frederick Banting, who co-discovered insulin (the hormone that opens the gate for sugar to enter the body cells) in 1922 along with Charles Best.
Unfortunately, the day arrived this year while we were struggling to cope with the Covid-19 pandemic, but I thought it would be an opportunity to review the relationship between Covid-19 and diabetes.
We know that diabetics are prone to infections, but are they particularly at risk of getting Covid-19? And what about the severity of Covid-19 infection among diabetics – and the eventual outcome?
And an even more interesting question is this: does Covid-19 actually cause diabetes? If so, which type – type1, type2 or possibly even a new strain of diabetes? I will cover these questions and more in this article.
Are diabetics at risk of severe Covid-19 infection?
Reports from China show that diabetes is the second most common comorbidity (after hypertension) in patients hospitalised with Covid-19. Eight studies documented that 9.7% of Covid-19 patients were diabetic. However, as 11% of the population has diabetes, this confirms that diabetics are not more likely to have Covid-19 than others.
Other reports, though, confirm that a patient with type1 or type2 diabetes is at high risk of a severe Covid-19 infection. This mostly attributable to other comorbidities such as obesity, hypertension and heart disease, as well as pro-inflammatory and coagulative states – i.e. problems common in diabetics.
To be clear, it is probably those conditions, which diabetics often carry, rather than the diabetes itself, which makes them vulnerable.
The acute respiratory distress syndrome due to Covid-19 infection can cause respiratory acidosis with a negative impact on the pancreatic beta cell, causing ketoacidosis, a known complication of diabetes. This means that diabetics with Covid-19 are likely to require intensive care and to have a high level of mortality.
Studies report diabetics to be low in innate humoral immunity, manifested as low Complement 4 (C4), which increases the severity of the disease in diabetics compared to non-diabetics.
Diabetics were also found to have a high level of pro-inflammatory cytokines, including TNF-alpha. Interleukin 6 and 8 (IL-6 and IL-8) are also high in diabetics.
Formation of advance glycaemic products (AGES) due to high blood sugar plays a major role in damaging the immune cells and proteins. You can measure your level of glycation damage by checking your HbA1C, a simple test available everywhere.
All the above factors make diabetics prone to high inflammation and an overreactive immune system, leading to more severe Covid-19 infections.
Diabetics presenting with metabolic complications of diabetes, including diabetic ketoacidosis and hyperosmolarity, require high doses of insulin, iv fluids, electrolytes and iv antibiotics under close observation in the intensive care unit.
Patients with diabetes are biologically 10 years older than those without. This automatically puts a high proportion of diabetics prematurely into the older age group. And we know that age is associated with a poor prognosis with Covid-19.
Looking at other sub-divisions of the population, non-white ethnic minorities have a Covid-19 mortality rate that is 3 to 6 times higher than the white population. The cause is likely to be associated with socio-economic factors, while other reports point out that darker skin can result in low vitamin D, a very important factor in preventing Covid-19 infection.
Other reports explained the relationship between age, Covid-19 and diabetes in three ways: firstly, diabetes increases in those over 65; secondly, people of 65 and older are likely to have had diabetes for longer and thus with greater complications; and thirdly, diabetes and old age also share comorbidities such as hypertension, obesity and heart disease
20-30% of Covid-19 deaths are linked to diabetes
The American Diabetic Association advises that diabetics should be brought to hospital immediately if they develop difficulty breathing, have persistent pain or pressure on the chest, experience a new onset of confusion, an inability to wake or stay awake, or blueish lips or face.
During the pandemic, most routine appointments including diabetic reviews are being delayed or postponed, which affects the quality of care, and can result in a higher rate of diabetic complications.
On the other hand, many diabetics do not want to attend hospitals for fear of catching Covid-19. These fears should be addressed appropriately, maybe relocating diabetes follow-up clinics or using virtual methods.
Covid-19 can trigger diabetes in healthy people. We know it causes lung and kidney damage and could be the underlying cause of diabetes in some patients.
However, the underlying process by which the virus influences glucose metabolism is not clear. We do not know whether it could result in type1, type2 or possibly a new form of diabetes.
Some evidence suggests that ACE2 (which is crucial to glucose metabolism) allows the virus into human cells. Beta cells contain significant numbers of ACE2 receptors, so, in theory, Covid-19 could damage these cells and cause diabetes.
This is quite complex! ACE2 receptors are expressed in metabolic organs, including the pancreatic beta cell, adipose tissue, the small intestine and the kidneys. Thus, it is possible that the virus causes an alteration of glucose metabolism in pre-existing diabetics or creates a new strain of the disease.
It is not clear whether these changes persist when the infection resolves, as we don’t know if Covid-19 changes the underlying pathology in diabetics.
Diabetes causes the partial blockage of blood vessels due to atherosclerosis. while Covid-19 can result in clots causing complete blockage of arteries with serious consequences. In this way, Covid-19 can cause serious vascular complications like stroke and kidney damage in diabetics.
Covid-19 can trigger diabetes in healthy people
Otherwise, healthy people often present with ketoacidosis as the first sign of diabetes during a Covid-19 infection. This can be explained by the possible effect of Covid-19 damaging the pancreatic beta cell, causing diabetes.
People with sudden onset diabetes have significant insulin resistance, requiring an increased dose of intravenous insulin. This could be due to Covid-19 destroying the insulin-producing cells.
Diabetes frequently comes to light for the first time as a complication to heart attack or stroke. Covid-19 may be another of these triggers for diabetes.
The acute respiratory distress syndrome due to Covid-19 can cause respiratory acidosis with a negative impact on the pancreatic beta cell, causing ketoacidosis in a diabetic or hyperglycaemia in a person not known to be diabetic.
One 19-year-old German man presented with severe fatigue, dry mouth, severe (unexplained) weight loss, polyuria (frequent urination) and poly Dipsea (extreme thirst.) He tested positive for a genetic variant associated with type1 diabetes but had no diagnostic antibodies.
Because of this, his blood didn’t contain the type of immune cells that are typical of damaged pancreatic cells. Covid-19 patients admitted to hospital with high blood sugar and ketone bodies may have difficulty burning sugars and hence move to ketones as an alternative source of fuel.
New York endocrinologist Caroline Messer reported an outbreak of autoimmune diabetes since the pandemic, which could be antibody-negative type1 diabetes, or could be a new type of diabetes.
Viruses that cause severe acute respiratory syndrome (SARS) have been linked with autoimmune conditions such as type1 diabetes. Organs involved in controlling blood sugar are rich in ACE2 that SARS-cov2 uses to infect cells.
The virus can infect the organoids alpha and beta. Alpha produces the glucagon to raise blood sugar, while beta produces insulin to lower blood sugar. The virus can also produce proteins and inflammatory cytokines that trigger an immune response to kill beta islet cells.
As there is no hard evidence to support the claim that Covid-19 can cause diabetes, there is global interest in establishing a Covid-19 register, to study the characteristics of Covid-19 related diabetes to determine its pathogeneses, management and outcome. The register was established at Kings College London, and hopefully, over time this data can be analysed to explore the possible relationship between Covid-19 and diabetes.
Weight gain: the indirect (real?) link between Covid-19 and diabetes
I have noticed that Covid-19 is causing diabetes faster indirectly than directly!
We had the first lockdown and now a second, and now most of us are working from home. This has resulted in significant weight gain, as we eat more due to stress and exercise far less. I am sure that the national BMI must have risen from the last UK figure of 29. This could produce a pandemic of obesity and associated diabetes, parallel with the one caused directly by Covid-19.
I was mentioning this fact in a TV interview and suddenly the presenter interrupted me saying that she recently saw a cartoon presenting this in a very impressive way. The cartoon showed obese people looking at their tiny door and asking how they could get out. They had gained too much weight during the pandemic and now the door was too small for them!
This is why I think there is no better time than now to reclaim your health. People suffering with weight gain and obesity can be highly motivated, and will work hard to get back to their ideal weight, and put diabetes and other associated metabolic conditions such as high blood pressure, heart disease, arthritis and cancer behind them.
It is possible to get your diabetes into long term or permanent remission if you can find out the underlying causes behind your metabolic syndrome and do something about them to regain your ideal bodyweight. The search should be thorough, and you can benefit from hi-tech tests to explore your genetic weaknesses and your nutrition. We can then define a plan to correct your biochemistry at a cellular level, in order to address the root cause of the problems, so that you can enjoy optimal health and well-being, and ensure a long and high-quality lifespan.
For diabetics, in order to stay healthy and prevent Covid-19, please do consume food rich in vitamins B, C and D, zinc, Selenium, Quercetin and EGCG (green tea), and use high quality supplements, if necessary.
Patients with type1 diabetes have no choice but to use insulin to control their diabetes, but even here, lifestyle management can help you to reduce your dose.
Patients who cannot benefit from lifestyle management should stay on their medications. For example, ACE inhibitors reduce the risk of renal complications and treat comorbidities such as hypertension.
(And by the way, ACE inhibitors medication increases the expression of ACE protein, which helps the virus enter the cell. Cardiologists were very interested in this genetic expression, wanting to see if it was having a beneficial or deleterious effect. Fortunately, all the reports came back reassuring: these pills do not put patients at risk of Covid-19 and hence they should continue taking their pills as usual.)
As you can see, my friends, this is a complex area that is just starting to be explored. If you would like to share any experiences that you have had in relation to Covid-19, or to diabetes in this time of pandemic, or to any possible link between the two, I would be fascinated to hear your story.
And of course, in airing your thoughts, you may well help others, triggering ideas and realisations that carry them further along the path to a successful conclusion to their Covid-19 and/or diabetes journey. Thank you!
Diabetes and risk from Covid-19:
Coronavirus might trigger diabetes:
Can Covid-19 cause diabetes?:
Covid-19 triggering diabetes in healthy people:
Diabetes and Covid-19:
Covid-19 hits older people harder than children: