Having hyperglycemia (high blood glucose) was a better predictor of developing severe COVID-19 than a diagnosis of diabetes, according to a new study presented at the Endocrine Society’s virtual ENDO 2021 meeting and described in an article at MedPage Today.
At a single hospital facility in New York City, 708 people admitted for COVID-19 treatment were included in the analysis. Out of these study participants, 383 had a previous diagnosis of diabetes, while 325 others did not. In both groups, researchers looked at how having high blood glucose at the time of admission to the hospital affected a range of outcomes — including admission to the intensive care unit (ICU), requiring a breathing tube and death. The average age of participants was 68, and their average body-mass index (BMI, a measure of body weight that takes height into account) was 29, close to the boundary between overweight and obese. Most participants, 89%, identified as non-Hispanic Black. At the time of their hospital admission, 82% of participants had hypertension (high blood pressure), 38% were obese and 18% had chronic kidney disease.
To get cutting-edge diabetes news, strategies for blood glucose management, nutrition tips, healthy recipes, and more delivered straight to your inbox, sign up for our free newsletter!
High glucose linked to worse outcomes
The researchers found a range of risk levels for different outcomes based on diabetes status and glucose levels at which they were admitted to the hospital. For people with a diagnosis of diabetes whose glucose was over 140 mg/dl at the time of hospital admission (71% of those with diabetes), the risk of needing a breathing tube was 2.4 times as high as for the overall group, and the risk of admission to the ICU was also 2.4 times as high. For those with diabetes whose glucose level was at least 180 mg/dl at the time of admission (57% of those with diabetes), the risk of death during their hospital stay was 1.8 times as high, after adjusting for a number of factors including age, sex, white blood cell count, hypertension, cardiovascular disease, chronic kidney disease and BMI.
But people without previously diagnosed diabetes who had high blood glucose at the time of hospital admission had even worse outcomes in many areas. For those with a glucose level of at least 140 mg/dl (32% of those without diabetes), the risk of needing a breathing tube was 2.3 times as high, the risk of ICU admission was 3.5 times as high, and the risk of acute kidney injury was 2.3 times as high. Perhaps most importantly, the risk of death was 2.0 times as high as for other people in the analysis. For people without diabetes whose glucose level was at least 180 mg/dl at the time of hospital admission (13% of those without diabetes), the risk of needing a breathing tube was 2.7 times as high, the risk of ICU admission was 2.9 times as high, and the risk of death was 4.0 times as high.
What’s unclear from all of these results is whether most people would have had high blood glucose even if they didn’t have COVID-19, or whether COVID-19 caused these high glucose levels. It stands to reason that even if COVID-19 was the cause of high glucose, at least some people with diabetes — particularly those who take insulin — would be able to bring their elevated glucose down by taking more insulin. People without diabetes, on the other hand, would probably lack the ability even to know that their glucose was high until they arrived at the hospital.
But at least for some people with diabetes, “These results raise the testable hypothesis that intensive glucose control with more frequent monitoring and treatment with insulin to a target glucose of less than 140 could improve outcomes in patients hospitalized with COVID-19,” said study author Samara Skwiersky, MD, of SUNY Downstate Medical Center in Brooklyn, New York, at a press conference.
Want to learn more about coronavirus and diabetes? Read our latest COVID-19 updates.
Living with type 2 diabetes? Check out our free type 2 e-course!