Dr. Michal Shauly-Aharonov
Dr. Michal Shauly-AharonovCourtesy

Elevated pre-infection blood sugar levels are correlated with a greater risk of severe COVID-19 cases even in non-diabetics, according to a new study.

Prior to the study, which was first published in the PLoS ONE journal, diabetes patients were already known to be at a higher risk for severe COVID-19 infection. But the new research from the Jerusalem College of Technology (JCT), Hebrew University of Jerusalem, the Kupat Holim Meuhedet HMO, and Hadassah Medical Center represented the first study to explore the correlation between sugar levels and the risk of severe COVID-19 morbidity, regardless of a diabetes diagnosis.

In patients diagnosed with diabetes, the highest risk (1 of 4 patients) of contracting severe COVID-19 was found in patients with low sugar values — below 80 mg/dl. The lowest risk (1 of 12) was found in patients with sugar values of 106-125 mg/dl. (The standard blood sugar level for an adult is 70-100 mg/dL, after having fasted at least eight hours.)

For patients with no diagnosis of diabetes, the higher the sugar values, the greater the risk of severe COVID-19. Patients with sugar values while fasting of 105-125 mg/dl were 1.5 times more at risk of developing severe COVID-19 than patients with sugar values less than 105. Patients with sugar values of 125-140 mg/dl were twice as likely to develop COVID-19 complications than patients with sugar values less than 105.

The research examined all members of Kupat Holim Meuhedet over age 18, including 37,121 subjects (16.7 percent of the total group) who registered a positive COVID-19 PCR test between March and October 2020. Additionally, 707 of subjects were seriously ill (1.9 percent), 244 died (34.5 percent), 188 were admitted to the ICU (26.5 percent), and 538 were hospitalized for 10 days or more (76 percent).

“The aim of the study was to locate risk factors for COVID-19 severe morbidity which could be handled in advance, so we could raise the awareness of those factors among the general public," said Dr. Michal Shauly-Aharonov of the Department of Industrial and Management Engineering at JCT and Hebrew University’s School of Public Health.

“Locating factors related to severe morbidity and death, G-d forbid, is important principally to shed light on the populations at risk, so they can receive priority in receiving vaccines. As far as we know, no population-based studies had previously been published correlating glucose levels before infection and the risk level of contracting COVID-19 in patients suffering or not suffering from diabetes.”

Dr. Orit Bernholtz-Gulchin, head of the Kupat Holim Meuhedet regional diabetes clinic, said the findings mean that the medical community’s emphasis for those diagnosed with diabetes “should be placed on preventing hypoglycemia (a condition in which blood sugar level drops radically from normative levels) in populations found to be at risk of severe COVID-19 comorbidity.”

The researchers also recommended paying special attention to patients with no diagnosis of diabetes who show abnormal sugar levels during fasting or who show elevated HbA1C hemoglobin levels, as well as low sugar-value diabetics, who are also at increased risk of COVID-19 complications.

“The study shows very strongly how much can be learned from quality and continuous medical recording, such as the one we have in the Israeli health care system,” said Prof. Ora Paltiel of Hebrew University’s School of Public Health.