A study from Wuhan, China showed that non-diabetic COVID-19 patients with high blood sugar levels on admission to the hospital were more than twice as likely to die within a month and four times more likely to suffer the most serious complications caused by that disease (Diabetologia, July 10, 2020). The authors concluded that on admission for COVID-19, a fasting blood glucose level higher than 125 mg/dL (7.0 mmol/l) is an independent predictor for death within 28 days in patients with COVID-19 without a previous diagnosis of diabetes.
A study from the U.S. also showed an increased death rate for COVID-19 patients admitted to hospitals with high blood sugar levels (J Diabetes Sci Technol, May 9, 2020). Several previous studies show that diabetics are at markedly increased risk for dying from heart attacks, strokes, cancer and infections (Lancet, 2018;391(10138):2430–2440), and people who have high blood sugar levels on admission to a hospital for pneumonia are at increased risk for dying in the hospital (BMJ, 2012;344:e3397).
How High Blood Sugar Increases Risk of Death
COVID-19 can cause clots to form in and destroy the lungs, heart, kidneys, brain, liver and other parts of your body. High blood sugar can also cause clots, increasing the risk of this complication in patients with COVID-19. High blood sugar can prevent blood vessels from widening so the clots are more likely to block the flow of blood. High blood sugar can also cause the immune system to produce inflammatory cytokines, leading to “cytokine storm” where the body attacks its own cells and tissues rather than just fighting off the virus. The cytokine storm can eventually kill a patient.
We do not completely understand why COVID-19 is a relatively benign disease for many people and very serious or even deadly for others. We do know that you are at risk for complications if you have any defect in your immune system, such as diabetes, heart disease, an auto-immune disease, lung disease, kidney disease, cancer, high blood pressure, a chronic infection and so forth.
You are at increased risk for serious complications from COVID-19 if you have high blood sugar after meals or have an obese belly, which specifically causes high blood sugar levels. This is one risk factor that you can improve immediately just by avoiding the foods that cause high rises in blood sugar: sugared drinks and sugar-added foods, and any processed food made with refined carbohydrates. See my report Restrict Added Sugars to Reduce Heart Attack Risk.
Note: I discussed this study and other aspects of COVID-19 on the radio show I did this week on WRTA in Altoona PA. You can listen here: https://soundcloud.com/talkradio985/dr-gabe-mirkin-july-2020-wrtas-the-11th-hour-with-doug-herendeen