‘No clear, direct link between long Covid and new onset of diabetes; post-Covid fatigue, lifestyle changes may trigger it’

Around one and a half years ago, the association was suspected. New cases of diabetes started coming after the first wave… The patients had very high sugar levels, higher than the cases which were coming in earlier. We published the data. We compared patients who came with pre-onset diabetes after the first wave to those who had new onset of diabetes before the pandemic. We found that the former had higher sugar levels and had far more problems than the other group. At the time, as more and more studies came in, multiple mechanisms were considered. We are also part of the International Registry for the new onset of diabetes after Covid.

So what could be the cause for patients developing diabetes during or after Covid infection in India? Number one, it could be that it is not the new onset of diabetes. It could be hidden diabetes, diabetes that was already present in the patient, and when these patients got the Covid infection and had to run blood tests later, the diabetes was detected. So pre-diabetes and diabetes were detected, and patients probably had both earlier.

The second reason could be that Covid-19 itself is creating the problem. The Covid-19-induced cytokine storm affects every part of the body, including the lungs and pancreas. Now the pancreas produces insulin and keeps the sugar level under control. So, insulin-producing cells were possibly attacked (in Covid infection).

In such cases of diabetes, where the patient did not have diabetes earlier – where their blood sugar level shot up suddenly during the hospital stay (for Covid), and where the sugar levels seemed like Type-1 diabetes levels, and there was acid in the urine – we treated them with insulin. There were cases like this reported in India. Subsequently, the blood sugar went down and insulin was taken off. Some people reverted to normal and they were not diabetic anymore. However, some of these patients continued to have diabetes but they didn’t require insulin. So in these cases, we can say that whatever damage was done during Covid infection was somewhat repaired, the blood sugar levels went down and the situation was controlled with oral drugs. That can be called Covid-induced diabetes.

The third scenario is drug-induced diabetes. Certain drugs such as steroids were given in high doses (during Covid), and some patients who were susceptible to developing diabetes in the future, developed it due to steroid provocation now. When high doses of steroids were given for a longer time, in some patients the blood sugar went up and it was very difficult to control. Then, insulin was given. Once the steroid was withdrawn, the blood sugar levels went down to normal in some patients; they didn’t require any medication. In other patients, diabetes continued, but it was easily controlled.

So far, ‘long Covid’ has not been defined clearly, mainly due to its varying symptoms. However, there have been cases where people did not become severely ill on contracting the virus, but developed diabetes a few months later. Is there a link between long Covid and diabetes?

I do not think there is a very clear, direct relationship between long Covid-19 and new onset of diabetes. The only way it can occur is if the virus persists for a very long time and creates inflammation. I don’t think that is a common phenomenon. More often, what is happening is that patients who have recovered from Covid-19 may sometimes have other symptoms which preclude them from exercising like they were doing earlier… They are under immense psychological stress, they are not able to sleep, they are fatigued. So their whole lifestyle is disturbed. That again is a trigger for metabolic problems, including blood pressure and diabetes. Such diabetes is secondary… it occurs due to lifestyle changes due to long Covid-19 related problems.

What are the symptoms that suggest high blood sugar levels after Covid recovery?

Fifty per cent of the time there are no symptoms, or they merge into symptoms that already exist. After recovery, we tell patients to get their sugar levels tested after 15, 30 or 60 days. Some (cases of high sugar levels) can get detected through this. Most patients don’t have symptoms but their sugar levels are high. On the other hand, if the patient has very high sugar, there will be an increase in urination, there will be increased fatigue, and they will probably lose weight too. If the sugar level is in the medium range, then the patient might not have any symptoms or have mild symptoms… So it is difficult to uncover sometimes.

In such a situation, what key preventive measures can one take? Are there any specific tests?

The measures that we recommend to recover from long Covid also, somewhat, work for diabetes. For instance, a good diet is recommended. It must cover various micronutrient deficiencies, the quantity of protein should be high, there must be fewer carbohydrates, and there should be plenty of fruits and vegetables. If this is taken care of, at least the deficiencies which are diet, nutrient, and micro-nutrient related are covered, and some part of prevention is also covered.

The second thing is more difficult to do: physical exercise and rehabilitation programmes. Sometimes if Covid is severe, then people have high inflammatory markers, and take a long time to return to exercise — which is absolutely important as far as the metabolism of sugar is considered. So after a period of rest, which will depend on the (severity) of the Covid illness, they should be put on a rehabilitation programme along with their physician and one physiotherapist must be involved. It should be a week-by-week rehabilitation programme, which will increase physical activity and muscle strength. That will also help in the prevention of any metabolic problems such as diabetes.

If they have a family history of diabetes, if they have had steroid-induced high sugar, if they are obese, or if the patient already has hypertension and heart disease, they should check their sugar levels at least once in four weeks after Covid. If their sugar level is high, then they should contact a physician, and then checking their sugar levels for the next two-three months will not do any harm.

You can check it at home with the help of a glucometer, and if the fasting sugar level is above 126, and two hours after meals it is above 200, they should contact a physician. If it is between 100-145 (fasting) and between 140-199 (post meals), then they are in the pre-diabetes category. They have to be cautious and should contact their physician, who may not give the patient any drug, as lifestyle measures might suffice.

So when does one see a specialist?

You should understand that 70% of diabetes cases in this country are treated by general physicians. A physician who knows the patient will do a good job. I do not think specialist consultation is really required at this stage. However, if the patient has multiple co-morbidities… For example, a patient has high sugar in the range of 200-250 and also has a kidney problem, or is unable to walk for long and is feeling fatigued all the time, that’s when specialist consultation is required.

Can Covid-19 worsen type-2 diabetes in patients?

We conducted a study where we saw that sugar levels of many diabetic patients go totally haywire (after Covid). There are reasons for that. During the initial phase (of the pandemic), people did not exercise due to the lockdown, they did not go out of their homes. Their diet went all haywire. But recently, in the last 6-8 months, people are going out and, to some extent, this part is taken care of. But still, we have seen that after Covid-19, the blood glucose control goes haywire. But this is not very specific to Covid. For instance, a person who is diabetic and has typhoid fever, his sugar level will shoot up too. But Covid-19, in addition, attacks the pancreas and that component has to be kept in mind as well. Covid-19 requires steroid treatment, and that component has to be kept in mind too. Probably, when compared to other infections, in Covid-19, there is a higher tendency for blood sugar levels to increase in existing diabetic patients.

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