Trends in Serum Shifts: Unveiling Hyperglycaemia Links Post-COVID-19 Vaccination

Background: Clinical endocrinology has observed emerging endocrine complications following COVID-19 vaccination, amidst successful reductions in COVID-19 hospitalizations and deaths. The Pfizer-BioNTech and Moderna mRNA vaccines have demonstrated efficacy. Reports indicate a potential association between SARS-CoV-2 vaccination and diabetes, exploring interactions with ACE-2 receptors and molecular mimicry. Additionally, altered liver and kidney function tests post-vaccination prompt investigation into their role in predicting type 2 diabetes. This study aims to explore these biochemical abnormalities in a case-control, single-centre prospective study. Materials and Methods: This prospective study aimed to evaluate a total of five hundred healthy donors, out of which 203 qualified for final analysis. Participants were selected based on their vaccination status with a COVID-19 vaccine and prior exposure to the SARS-CoV-2 virus. Donors without prior SARS-CoV-2 infection were excluded from the study. Included participants were adults who had received three doses of the COVID-19 vaccine. Results: A total of 203 individuals were included in the study, comprising 104 with type 2 diabetes mellitus (T2DM) and 99 without. Demographic characteristics including age, sex, nationality, Rh factors, ABO blood groups, liver function tests (LFT), kidney function tests (KFT), lactate dehydrogenase (LDH), and mineral ion levels were analysed. Among the participants, the distribution based on HbA1c levels showed 47.8% with HbA1c <7% classified as normal, 38.48% with HbA1c 8-10% classified as high, and 16.64% with HbA1c >10% classified as uncontrolled diabetes. Significant findings included a decrease in magnesium levels to 0.77±0.82 mmol/L (p<0.04*), an increase in LDH levels to 420.70±356.26 µL (p<0.01*), and elevated levels of alkaline phosphatase (143.22 ± 142.62 µL, p<0.001), gamma-glutamyl transferase (GGT) (55.70 ± 32.20 µL, p<0.001), and serum bilirubin (9.23 ± 4.87 µmol/L, p<0.001). Creatinine levels were significantly lower at 116.75 ± 101.94 µmol/L (p<0.001), while uric acid levels were significantly elevated at 305.92 ± 145.04 µmol/L (p<0.001) in individuals with uncontrolled HbA1c >10%. A majority of these individuals belonged to the O+ blood group. Conclusion: This study underscores significant shifts in serum biomarkers and their complex interplay with mRNA-based SARS-CoV-2 vaccination and diabetes, particularly in uncontrolled cases. The findings suggest potential autoimmune reactions triggered by the self-adjuvant properties of mRNA and polyethylene glycol lipid conjugates. Variations observed among different blood groups may correspond to racial disparities influencing molecular mimicry mechanisms. Despite these insights, the underlying pathophysiological mechanisms remain unclear, highlighting the critical need for further research to validate and expand upon these findings.