The Link between COVID Hospitalisation and Diabetes

Dr Ambrish Mithal discusses how Diabetes and COVID related hospitalisation are interlinked.
Male online cardiologist at work
Male online cardiologist at work

In early 2020, when cases of COVID-19 started rising throughout the world, people with co-morbidities such as Diabetes, heart disease, high blood pressure and kidney disease were more likely to face adverse outcomes as compared to those who did not have these conditions. The adverse outcomes of COVID in China, Europe and the U.S., were linked to these comorbidities.

COVID-19 in India

India has one of the highest numbers of people with Diabetes in the world and this number continues to rise. The urban areas of India, in particular the metropolitan cities, have a higher prevalence of Diabetes than the rural areas. COVID has impacted urban metropolitan areas much more than the rural areas, explaining in part the occurrence of COVID in people with Diabetes.

Among people living in metropolitan cities (like Delhi) 15-20 per cent has Diabetes by the age of 40. At the age of 60, this number increases to 35-40 per cent. Looking at such high figures, it is evident that the older generation was severely impacted with COVID because they already have significant co-morbidities. Therefore, metabolic syndrome (a cluster of conditions such as high blood sugar, high waist circumference, high cholesterol levels and excess body fat) and COVID form a dangerous duo even though India has seen lower COVID fatality rate than any western country.

This could be attributed to various factors such as a higher proportion of young people in India or a stronger immunity status, but certainly not because of our superior metabolic parameters. People who are succumbing to COVID-19 in India have a high proportion of metabolic syndrome.

Metabolic syndrome and COVID-19

Whether people with Diabetes or other metabolic syndromes are at a greater risk of contracting COVID is yet unknown. Most research studies do not indicate an increased risk of contracting COVID in people with Diabetes or other metabolic syndrome but show a higher risk of poor outcomes in this group due to COVID.

Interestingly, among all the comorbidities, obesity has been consistently found to have an increased risk of contracting COVID infection as well as having poor outcomes. Therefore, weight as a component of metabolic syndrome is an important indicator of those who are likely to contract the COVID infection.

In the U.S. almost all young hospitalised patients who had severe COVID were obese. Obesity seems to not only worsen outcomes but may also increase the risk of contracting COVID.

COVID-19 outcomes in people with Diabetes

Our research study, published in the journal Diabetes & Metabolic Syndrome: Clinical Research & Reviews, observed 401 people who were hospitalised due to COVID. They were classified according to the WHO criteria as either mild or severe. (The WHO criteria do not have a moderate disease group). Out of these, 47 per cent had pre-existin0g Diabetes and 5.2 per cent had new-onset hyperglycaemia (high blood sugar levels).

When this group with Diabetes was observed, it was found that the proportion of severe cases (that required ICU admission and oxygen) doubled. All of them had double the risk when compared to people without Diabetes. Interestingly, there was a significant correlation seen between outcome severity course and baseline HbA1c. The level of blood sugar control at the time of admission did play a role in worsening outcomes.

Out of all the studies reported, our study has shown the highest prevalence of pre-existing Diabetes in any COVID cohort across the world. There are other interesting facts as well. Other studies have shown a higher prevalence of new-onset hyperglycaemia, our study showed only 5 per cent. Also, the number of pre-existing but unknown Diabetes was less. This is probably because people in the metropolitan cities go for regular health check-ups.

Hypertension and COVID-19 disease

Hypertension (high blood pressure) also seems to play an important role in determining COVID outcomes. After Diabetes, hypertension was the most common comorbidity found in these people. Nearly 40.9 per cent had hypertension at the time of admission for COVID. About 8.7 per cent had a narrowing of the arteries due to blockage and 2.99 per cent people had chronic kidney disease.

Quite clearly, all these were associated with greater morbidity and mortality. Hypertension was associated with a higher proportion of severe cases, mortality, ICU admission and oxygen administration. It has been seen that not just Diabetes but a combination of Diabetes, heart disease, blood pressure and kidney disease could worsen COVID outcomes. People with Diabetes tend to have poorer outcomes. I think it is important to look at the complete picture of these conditions together and not just as independent diseases.

New-onset Diabetes and COVID-19

New-onset hyperglycaemia is always seen in stressful situations. The severity of new-onset hyperglycaemia was tremendous and it was, to an extent, blood sugar levels that I haven't seen in a long time. People were reporting blood sugars of 600-700 mg/dL while hospitalised.

It could simply be a manifestation of the severe stress produced by the virus or an effect of glucocorticoid administration and most hospitalised people were on glucocorticoids. The notable part is that this group with new-onset hyperglycaemia had the poorest outcome. If looked at the outcomes of our study, 21 people had new-onset hyperglycaemia and had the worst outcomes. So, it is important to understand that new-onset hyperglycaemia is a marker of the severity of the disease.

An important thing to look at is that two of our patients did develop new-onset hyperglycaemia without any glucocorticoid administration. So, either the stress of the infection was such that without glucocorticoid one can develop new hyperglycaemia or the virus itself is doing something to produce new-onset hyperglycaemia. It remains to be seen which of these patients recovered and which of them continued to have Diabetes.

The impact of staying indoors

Staying indoors has impacted people in different ways. A small proportion of people have taken this opportunity to improve their health. Some people are aware of what is required but didn't have the time to pay attention to their health. During the pandemic and resulting lockdown, they followed a healthier lifestyle with regular exercise and a balanced diet.

But a majority of people saw a worsening of their health parameters during this period. People with Diabetes, although not eating out anymore, have increased their food intake. After indulging in excess food, they could not go out to exercise due to the pandemic or a dislike for exercising indoors. This has resulted in an increase in daily calorie intake followed by decreased physical activity. Both of these factors seem to have impacted people with Diabetes.

In some cases, a lack of Diabetes supplies such as glucose measuring strips, doctor's appointment and testing impacted Diabetes control during the initial days. After these issues were overcome, people were able to contact their doctors. Doctors started online consultation using video chats and home sample blood collection facility also started. This was helpful as people could get their check-ups done. Medical supplies were restored and became available within a month of the lockdown in India.

A majority of people with Diabetes continue to consult their doctors via video consultation and telemedicine. This helped people stay motivated and ensured that they could get back on track. But if ignored, blood sugar control saw a worsening trend during this period.

People with Diabetes and high blood pressure need to be aware of the risks of COVID but there is no need for panic. What is important for people with Diabetes and high blood pressure is to follow all the mandated precautions. It is of utmost importance to wear a mask, maintain physical distancing, avoid indoor gatherings (if meeting people then it is better to meet them in an open space while wearing a mask), sanitise and wash your hands frequently.

Along with these precautions, people with Diabetes should check their blood sugar levels and blood pressure regularly, consult their doctor regularly to control blood pressure and blood sugar levels and stay alert about their health parameters. Despite all this, if a person contracts COVID then maintaining HbA1c of 6.5-7 per cent would yield better outcomes.

Dr Ambrish Mithal is the Chairman and Head of Endocrinology and Diabetology at Max Healthcare, Delhi and Gurugram.

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