It appears that COVID-19 is not leaving us anytime soon.

As the pandemic continues, scientists are working to better understand this deadly virus and why some people have mild cases of the disease while for others, infection turns fatal.

Recently, we reported on a study confirming what doctors nationwide have noted anecdotally among COVID patients, and what I also suspected.

Researchers found that people with obesity, diabetes and high blood pressure were at a higher risk for complications from COVID-19. They published their findings in the Journal of the American Medical Association.1

Since then, additional research has emerged on pre-existing health conditions and COVID, and the revelations are valuable.

Diabetes and The Coronavirus

One important study focused specifically on the effect of COVID-19 in hospitalized patients with diabetes.

Dubbed the CORONADO study, researchers analyzed 1,317 patients admitted to 53 French hospitals between March 10 and March 31, 2020. The study shows that two-thirds of COVID-19 patients with diabetes admitted to the hospital were men, and the average age of all the COVID patients was 70 years.

Researchers found that one in ten patients died within seven days of hospital admission, and one in five was intubated and mechanically ventilated within the same period.2

Interestingly, worse blood sugar control did not seem to impact a patient’s outcome. However, the presence of diabetic complications and increasing age increased the risk of death.

Additionally, as noted in other research, increased body mass index (BMI) was associated with both higher risk of needing mechanical ventilation and with higher risk of death.

Perhaps even more interesting are the results of the first study to examine COVID-19 patient outcomes among patients who did not have a previous diagnosis of diabetes.

The Effects of High Fasting Blood Sugar on COVID-19 Patients

The study followed 605 COVID-19 patients from Wuhan, China with a median age of 59 years. More than half—322—were men.

A total of 208 patients had one or more underlying condition (but not diagnosed diabetes), of which high blood pressure was the most common.

Researchers found almost one-third of patients fell into the highest category of fasting blood glucose (FBG) on admission (7.0 mmol/L). This number, if found consistently, would result in a diagnosis of type 2 diabetes. Out of the 605 COVID patients, 114 died in hospital.

The results showed that patients with the highest fasting blood sugar yet no diabetes diagnosis had double the risk of death from COVID-19. They also had an increased risk of severe complications. Researchers published their findings in the journal Diabetologia, the journal of the European Association for the Study of Diabetes [EASD].3

Why High Blood Sugar Leads to Complications

The authors of the CORONADO study believe there are a few reasons for the link between hyperglycemia (abnormally high blood sugar) and poor COVID-19 outcomes.

These possible mechanisms for higher risk of death include hyperglycemia-induced changes in blood clotting, worsening of endothelial function (the interior walls of blood vessels), and overproduction of inflammatory cytokines produced by the immune system, otherwise known as the cytokine storm, which has been observed to be a huge factor in COVID deaths.

“Blood sugar testing and control should be recommended to all COVID-19 patients even if they do not have pre-existing diabetes, as most COVID-19 patients are prone to glucose metabolic disorders,” the CORONADO authors conclude.

Additionally, the authors say that measuring fasting blood glucose can lead to an early intervention to treat hyperglycemia, which can help improve the overall outcomes for COVID-19 treatment.

Take Control of Your Blood Sugar

If you haven’t done so lately, it’s not a bad idea to get a blood test to find out if your blood sugar level is worrisome.

If it’s high, this research is all the more reason to take the appropriate steps to bring it back into the healthy range. This is something we can all do proactively, at home, to improve our odds of surviving the coronavirus if we get it.

In many cases, you can stop those fasting blood glucose numbers from rising with a healthy diet and regular exercise. Start by exercising regularly, cutting out sugar, controlling your carbohydrate intake and increasing your intake of fiber. Then, choose foods with a low glycemic index.

This is wise advice not just to protect against COVID-19, but also to protect against diabetes, heart disease, obesity and cancer—all of which can rob you of life quality and quantity.


  1. JAMA. 2020;323(20):2052-2059. doi:10.1001/jama.2020.6775
  2. https://medicalxpress.com/news/2020-05-covid-patients-diabetes-die-days.html
  3. Diabetologia, 2020; DOI: 10.1007/s00125-020-05209-1