Covid has fuelled diabetes pandemic

Umesh CS Yadav

Professor, Special Centre for Molecular Medicine, JNU

BEFORE Covid-19 was declared a pandemic by the World Health Organisation (WHO) in March 2020, the world was already facing another pandemic — diabetes. According to the Global Burden of Disease Study 2017, published recently in the Scientific Report journal, the global incidence rate of diabetes in 2017 was 2.3 crore, while in the same year, a total of 47.6 crore people were suffering from diabetes worldwide, suggesting its pandemic-scale spread.

The same study reported that India was at the second rank, with 6.8 crore diabetic patients, while China, with nearly nine crore diabetics, was at the top of the list. Every major country had a significant proportion of the population affected by diabetes.

A year and a half after the outbreak of Covid-19, a significant number of recovered patients have reportedly developed diabetic symptoms, having high blood glucose, both fasting as well as post-meal. This problem is found even in those people who never had diabetes before contracting Covid.

A clinical study was performed on a group of more than 550 hospitalised Covid patients in Italy to understand and document the glucose-related abnormalities in recovered patients, two months after the onset of Covid. The results, published recently in a reputed scientific journal, Nature Metabolism, show that nearly half of these patients were having steeply elevated blood glucose level while one-fourth had normal glucose level. The remaining one-fourth had either a history of diabetes or was recently diagnosed with diabetes.

In a subgroup of the recovered patients, the researchers found that the patients had altered control of glucose metabolism, developed resistance to insulin and had abnormal level of cytokines. Some of these abnormalities were present even in those recovered patients who had normal glucose level and the symptoms lasted for at least two months.

Many recovered Covid patients also showed what is labelled as ‘long Covid’ in which some of the symptoms, including high glucose level, persist longer than expected. The study cautioned that these glycemic abnormalities could be associated with the ‘long Covid’ and needed intervention and medical care.

On an average, these recovered patients have reported a steep rise in their sugar level. Many of them required diabetic medicines or even insulin injections to control their precipitously elevated blood sugar level. Although in some patients, the level of glucose reverted to the average level with medication after a few weeks or months, in many others, elevated glucose persisted for a longer time. For the others, glucose would remain controlled with medicines, but as soon as the medication was discontinued, the higher glucose level returned.

In the beginning of the pandemic, Covid-19 was reported to be more severe in those people who had pre-existing diabetes and during the course of the disease, the sugar level could increase dangerously to over 400-500 mg per deciliter, nearly four-five times more than the normal sugar in blood.

This surge would jeopardise the immune system and weaken the body’s fight against the virus. In such patients, the recovery from Covid was delayed, and at times, became fatal.

The increase in diabetes incidence in Covid-recovered patients was attributed to steroids, such as dexamethasone which was given to Covid patients rampantly to control the inflammation, especially during the second wave of Covid this year.

Patients with mild Covid symptoms, who did not require dexamethasone, took it anyway and, at times, even without the advice of a doctor.

The steroids are known to elevate the blood glucose and their higher dose for a longer duration could cause the blood sugar level to surge and remain elevated.

The study mentioned above also pinpoints that the Covid-related increase in diabetes may be associated with the damaging effect of the virus on the insulin-secreting beta cells in the pancreas. The researchers observed an aberrant functioning of beta cells in Covid patients, which may eventually get exhausted, leading to their death.

The notorious ‘cytokine storm’ that occurs during severe Covid is related to the highly increased level of certain chemicals secreted by our own immune cells. These chemicals, including interleukin-6 and TNF-alpha, are also known to kill the insulin-secreting beta cells.

Insulin is necessary to control the glucose level by directing the body cells to open the gates and take up the glucose from blood. But if insulin is not secreted, or, if secreted but not effective, as in the case of Type 2 diabetes, the glucose that we absorb from the food remains in the blood and accumulates. The cells and tissues bathe in this high glucose and get adversely affected as high glucose is toxic and detrimental to the organs, including the arteries, heart, nerves, kidneys and eyes.

Once the patients recover from Covid, the leftover beta cells may regenerate slowly and with proper management and care under a doctor, the Covid-acquired diabetes may be ‘cured’.

However, if the high blood glucose persists for even a few months in the recovered patients, it may be likely that they were either genetically predisposed to developing diabetes or they had diabetes prior to contracting Covid but did not know about it.

To control the elevated glucose level in the Covid-recovered patients, it is important that they check their blood sugar levels regularly, maintain a healthy body weight, and consume a balanced and low-sugar diet.

In addition, sugar-controlling medicines, as advised by the doctor, should be helpful in diminishing the glucose level as well as the damage caused by its surge during this period. Frequent checking of the blood glucose level and adjusting the medication accordingly is also crucial to recovering faster and progressing towards normalcy.

The International Diabetes Federation has predicted that the global prevalence of diabetes would increase to 69.3 crore by 2045 in the absence of effective prevention methods.

Covid has fuelled another pre-existing pandemic, going by the recent surge in the number of diabetes patients. More effective preventive and curative measures will be required to contain this double whammy for people’s health. 

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