COVID-19 Boosters Linked to Blood Sugar Spikes in People With Type 1 Diabetes: Study

A case of dangerously high glucose levels in a patient following a COVID-19 booster shot sparked Johns Hopkins physicians to probe deeper, revealing a subtle but significant link between the booster and short-term blood sugar spikes in adults with Type 1 diabetes.

First Hint of a Problem

In the summer of 2021, a 24-year-old woman with Type 1 diabetes, normally managed on 45 units of insulin daily, rushed into the emergency room. Heart pounding and breathing rapidly, her blood glucose levels were alarmingly high, and unresponsive to her regular insulin protocol.

During her initial day in the hospital, she required 220 units of insulin delivered through her veins – nearly five times her regular dose. Her body began to comply by the third day, her glucose levels cautiously retreating.

Perplexed by the sudden spike in blood glucose levels, doctors ruled out COVID-19 and possible infections for the woman experiencing diabetic ketoacidosis (DKA).

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The mystery lingered until Dr. Mihail “Misha” Zilbermint, a Johns Hopkins endocrinologist, noted a crucial detail: The sudden surge occurred just a day after the patient received her COVID-19 booster shot.

The focused study brought together 21 adult participants with Type 1 diabetes—8 received the Moderna and 13 the Pfizer-BioNTech booster—and scrutinized changes in their glycemic control and insulin usage around their vaccination time. Employing Dexcom G6 Pro continuous glucose monitors for ten days, the research sought to accurately track any shifts in glucose levels pre and post-vaccination.

Speaking to The Epoch Times, Dr. Andrew Demidowich, assistant professor in the Division of Endocrinology at Johns Hopkins Medicine noted, “To my knowledge, we are the first to explore COVID-19 boosters’ impact on glucose, using 24-hour data from real-time continuous glucose monitoring.”

The study illuminated a tangible shift in glucose levels post-vaccination among individuals with Type 1 diabetes. The average glucose level of participants rose from 163 to roughly 173 just a couple of days post-vaccination, a jump that’s considered statistically significant and not likely due to mere chance. Researchers also noted a temporary uptick in insulin resistance, hinting that the body wasn’t utilizing insulin as effectively as usual.

The study found that while COVID-19 booster vaccines had a generally minimal impact on glucose control, nudging it up by an average of 6 percent, Dr. Demidowich highlighted a critical observation: “One in four participants experienced a pronounced surge in blood sugar levels post-booster.”

However, the study authors state that, for most patients, the COVID-19 booster remains safe and is well tolerated, aligning with prior research on the primary vaccine series. Dr. Demidowich anticipates a possible, albeit likely milder, blood sugar surge post-vaccine in people with Type 2 diabetes, warranting further exploration into the nuanced interplay between vaccinations, immune responses, and glucose control across diabetes types.

Although the study substantiates the theory that insulin resistance, propelled by inflammation, is a key driver for hyperglycemia, it does not present a definitive answer.

Without quantifying inflammatory markers, the team admits the possibility of other contributing factors. The study’s authors point out, “The temporary elevation in glucose levels could be directly related to inflammatory mechanisms, or perhaps to other influences, such as changes in appetite or physical activity levels post-vaccination.”

Practical aspects of vaccination, such as feeling unwell, reduced physical activity, disrupted eating habits, or disturbed sleep, all play a role in glucose dynamics. Dr. Demidowich theorizes that any of these factors could collaboratively impact glucose levels following a vaccine booster, weaving a complex picture that necessitates a broader exploration.

Keeping Blood Sugar in Check After Vaccination

It’s crucial for those with diabetes to be mindful of potential glucose level spikes, not just following COVID-19 vaccinations but with all vaccines, owing to the body’s inherent immune response.

“While COVID-19 vaccines didn’t significantly impact glycemia, other vaccines like influenza, Tdap, or pneumococcal might have different effects. It’s crucial to identify patients more susceptible to severe post-vaccination hyperglycemia or DKA,” stated Dr. Zilbermint.

“Healthcare professionals should offer detailed information on the vaccine’s potential impact on blood glucose,” continued Dr. Zilbermint, adding that doctors should conduct a pre-vaccination assessment, evaluating the patient’s diabetes management plan to ensure it’s well controlled.

A strategic post-vaccine plan is vital, particularly during the first five days after the shot, advises Dr. Demidowich. He underscores the importance of diligent glucose testing, a solid insulin-adjustment strategy, and establishing a clear benchmark for when to seek professional help, ensuring a safety net for the potentially turbulent glycemic aftermath of vaccinations.