Acute hyperglycaemia after COVID-19 vaccination in patients with stable diabetes: A Case Series (Preprint)
Authors: Bhatti Rahila , Adhami Sara , Khamis Amar , Matfin Glenn 
Published: February 2021

BACKGROUND

The COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To date 267,258 cases have been reported in the United Arab Emirates (UAE) with 766 deaths.

In United States of America, the Centers for Disease Control and Prevention (CDC) has categorized diabetes in terms of ‘increased risk of severe illness’, if infected with COVID-19.

With availability of COVID-19 vaccinations worldwide, patients with diabetes are usually in the highest priority group to be vaccinated.5 Currently 2 vaccines are available in the UAE. These are the Pfizer-BioNTech and Sinopharm vaccines. The Pfizer-BioNTech ribonucleic acid (RNA) vaccine is composed of nucleoside-modified messenger RNA (modRNA) encoding a mutated form of the spike protein of SARS-CoV-2, which is encapsulated in lipid nanoparticles. It is administered by two injections at least 21 days apart. In contrast, Sinopharm is a chemically inactivated whole virus vaccine. It is also given by two injections administered at least 21-28 days apart.

OBJECTIVE

To describe 2 cases of patients with diabetes with stable glycaemic control who developed hyperglycaemia post COVID-19 vaccination

METHODS

Case presentation of 2 patients with diabetes who were seen in ambulatory setting in terms of their blood sugars in a private hospital in Dubai.

RESULTS

Case 1: A 51-year-old Asian male with a history of type 2 diabetes was reviewed in the ambulatory care setting following COVID-19 vaccination. His recent glycaemic control was good with glycosylated haemoglobin (HbA1c) 3 months prior being 7.5%. His usual glucose lowering therapy was xultophy injection (fixed-ratio combination of insulin degludec and liraglutide) 14 units at night, in addition to oral metformin 1000 mg twice daily. He had a history of ischaemic heart disease which was stable on therapy. He took his first dose of Pfizer-BioNTech vaccine on 30th December 2020. His fasting blood glucose values before vaccination was 105 mg/dl and after taking 1st dose of vaccination was 185 mg/dl.

Case 2: A 30-year-old female known to have type 1 diabetes was reviewed in the ambulatory care setting following COVID-19 vaccination. She is on continuous subcutaneous insulin infusion (CSII). Her HbA1c within last 3 months was 8.3%. She received Sinopharm vaccination on 18th January 2021. Her continuous glucose monitoring (CGM) data shows fasting blood glucose of 121 mg/dl day before vaccination. On the day of vaccination her fasting blood glucose was 233 mg/dl as her overnight blood sugars were high. Her fasting blood glucose increased to 216 mg/dl and stayed high throughout the day 1 post vaccination. On day 2 post vaccination it came down to 181 mg/dl and on day 3 it settled down to 127 mg/dl.

CONCLUSIONS

The purpose of this case series is to alert healthcare professionals regarding potential transient hyperglycaemia post-COVID-19 vaccination. The vaccination should be recommended for people with diabetes as benefits far outweighs the risk. However, patients should be educated in advance to keep a close eye on their blood glucose levels post vaccination and regarding sick-day rules. As ADA 2021 recommendations were developed before COVID-19 vaccines were widely available, no detailed information regarding COVID-19 vaccination is captured. 7