A DIABETES WAVE ON THE WAY? THE CONNECTION WITH COVID-19
In patients hospitalized with COVID-19, researchers have discovered a new long-term health concern: an increase in new-onset hyperglycemia that lasts months after infection. According to an Italian study, about half of the COVID-19 patients admitted to hospitals at the start of the pandemic had new cases of hyperglycemia, or high blood sugar levels. They also had less favorable outcomes.
"These people were never diabetic before," says
lead author Paolo Fiorina, MD, Ph.D., of Boston Children's Hospital's Division
of Nephrology. "However, about 46% of the patients were found to have new
hyperglycemia during admission." While the majority of cases improved,
about 35% of newly hyperglycemic patients remained that way for at least six
months after the infection.
Hyperglycemia persisted beyond infection
The study looked at the health of 551 people who were
admitted to a hospital in Italy between March and May 2020. A six-month
follow-up period was included after admission to the hospital.
Hyperglycemic patients also had more clinical concerns than patients with no signs of glucose abnormalities: longer hospitalizations, worse clinical symptoms, a higher need of oxygen, a higher need of ventilation AND more need of intensive care treatment
"We wanted to figure out why these patients did so
poorly compared to those who didn't have hyperglycemia," says Fiorina, who
previously published research showing that COVID-19 exacerbated diabetic
glucometabolic control. Nature Metabolism published the current study.
Hormones also out of balance
To learn more, all patients were given a glucose sensor when
they were admitted. The researchers discovered numerous abnormalities in
glucose metabolic control in hyperglycemic patients over time.
They also discovered that patients with hyperglycemia had
abnormal hormonal levels. Fiorina explains, "We discovered they were
severely hyperinsulinemic; they produced too much insulin." Pro-insulin,
an insulin precursor, was also abnormally high, as were markers of impaired
islet beta-cell function. Insulin is produced and secreted by beta cells in the
islets.
"Basically, the hormonal profile suggests that in those
patients with COVID-19, the endocrine pancreatic function is abnormal, and it
persists long after recovery," he says.
Inflammation from excess cytokines
The amount of inflammatory cytokines, such as IL-6 and
others, was severely abnormal in hyperglycemic patients.
"We hypothesized that blocking IL-6, and possibly other
cytokines, would improve beta cell function," says Fiorina, whose
hypothesis was confirmed. Patients who received anti-IL-6 therapy (tocilizumab)
improved their glycemic control more than those who did not receive the
medication.
A coming wave of diabetic patients?
While some patients' glucometabolic abnormalities improved
over time, especially after COVID-19 infection, other issues remained. In the
post-COVID-19 period, many patients had higher post-prandial (after-meal)
glucose levels and abnormal pancreatic hormones.
"This is one of the first studies to show that COVID-19
affects the pancreas directly," Fiorina says. "It suggests that the
virus is targeting the pancreas as well, potentially affecting not only the
acute phase of hospitalization but also the long-term health of these
patients."
The study emphasizes the importance of assessing pancreatic
function in COVID-19 patients both while they are in the hospital and over
time. "We observed glucose metabolic abnormalities during the day that
were not always present in a normal fasting test," Fiorina says.
In terms of treatment, there are still unanswered questions
about how to care for COVID-19-related glucose abnormalities. Should patients
be treated solely with anti-diabetic drugs such as insulin sensitizers, or should
anti-inflammatory drugs such as tocilizumab and other medications be used as
well?
"If you keep targeting and blocking insulin but have a strong and chronic inflammation, it could lead to chronic damage," Fiorina says, adding that larger studies to test anti-diabetic and anti-inflammatory treatment are needed. "When you consider how many patients have been hospitalized with COVID-19 and how many are still being hospitalized around the world, we could see a huge increase in the diabetic population."