MONDAY, July 13, 2020 (HealthDay News) -- Bodies stressed by severe COVID-19 could produce abnormally high blood sugar levels, even in people without diagnosed diabetes. And that appears tied to a doubling of the odds of dying from COVID-19, Chinese researchers report.
High blood sugar (glucose) levels, measured at the time of admission to the hospital, were also linked to more severe disease and complications, according to researchers led by Dr. Yang Jin, of the Union Hospital and Tongji Medical College, in Wuhan, China. Wuhan was the originating epicenter of the global pandemic of COVID-19.
As the researchers explained, diabetes has long been known to greatly raise the odds for severe and even fatal COVID-19 in people infected with the new coronavirus.
But what about the effect of high blood sugar levels, even in people who don't have a diabetes diagnosis?
To find out, Jin's group looked over the medical records of more than 600 consecutive patients treated at two Wuhan hospitals for nearly a month in January and February. Patients averaged 59 years of age.
The researchers looked especially at each patient's blood sugar readings, the severity of their COVID-19-linked pneumonia, and patient outcomes in terms of illness severity and death. None of the patients had been diagnosed with diabetes.
A total of 114 patients died in the hospital from their illness, Jin's team said. Men were 75% more likely to die than women.
A high level of fasting blood glucose was found to be highly predictive of death, the researchers reported July 10 in the journal Diabetologia.
That held true "regardless of whether the patient has [COVID-19-linked] pneumonia that is more or less severe," the team said -- suggesting that the effect of high blood sugar on the death risk is independent of just how severe the patient's respiratory illness might be.
Of the total patient group, about one-third (29%) fell into a category of very high fasting blood glucose -- so high that, if consistent over time, these patients would be diagnosed with having type 2 diabetes. Another 17% had levels that were similar to people in "pre-diabetes."
Patients in the very high blood sugar category were 2.3 times more likely to die of COVID-19 than those with the lowest blood sugar readings, the study showed, and even those with readings suggestive of pre-diabetes had a 71% higher risk of death.
The odds for dangerous complications of COVID-19 were also four times higher in people in the high blood sugar category, and 2.6 times higher in those with a pre-diabetes level of blood sugar, the Chinese team said in a news release from the European Association for the Study of Diabetes.
Diabetes expert Dr. Minisha Sood is an endocrinologist at Lenox Hill Hospital in New York City. Reading over the new study, she noted that even in non-diabetic people, blood sugar levels can spike in response to serious illness.
"The rise in blood sugar due to an illness is called stress hyperglycemia," she explained. "The body, under stress, produces hormones and a reaction to the illness which elevates blood glucose."
However, such spikes typically don't happen in previously healthy individuals, Sood noted.
"The higher blood glucose in patients who ultimately succumb to COVID-19 versus other patients with normal blood glucose despite a COVID-19 infection may be a sign that their underlying systems are not as healthy as those who do not have stress hyperglycemia," she said.
According to the Chinese authors, stress hyperglycemia may indeed have stricken many of the Wuhan patients, since the 29% of patients who landed in the highest blood sugar group "is much higher than the estimated prevalence of diabetes in the Chinese population at 12%."
Based on the findings, the study authors advised that close tracking of blood sugar levels be added to the list of tests that doctors use to monitor risks for patients battling COVID-19.
"The bottom line is that everyone will respond to illness in their unique way," she said, "and it would be helpful to have ways to predict who may have a worse outcome from a COVID-19 infection. Having a high blood glucose on admission to the hospital may be one of those predictive measures."
For more on COVID-19, head to the U.S. Centers for Disease Control and Prevention.
SOURCES: Minisha Sood, MD, endocrinologist, Lenox Hill Hospital, New York City; July 10, 2020, news release, European Association for the Study of Diabetes