Effects of the COVID-19 booster vaccine on glycemia and insulin resistance in people with type 1 diabetes: A prospective pilot study

SARS-CoV-2 booster vaccination does not worsen glycemia in people with type 1 diabetes using insulin pumps: an observational study

BACKGROUND

Despite an increased risk for adverse outcomes from SARS-CoV-2 infection among individuals with type 1 diabetes (T1D), vaccine hesitancy persists due to safety concerns including dysglycemia. The impact of booster vaccination on individuals using automated insulin delivery (AID) systems remains unclear.

METHODS

We used continuous glucose monitoring (CGM) data from 53 individuals with T1D using insulin pump therapy who received their third and/or fourth COVID-19 vaccination. CGM data from the 14 days before and 3 and 7 days after each vaccination were compared. The primary outcome was glucose time in range (TIR) (70-180 mg/dL) 3 and 7 days post-vaccination compared with the 14 days prior. Secondary outcomes included other CGM metrics such as time below range (< 70 mg/dL), time above range (> 180 mg/dL), mean glucose, co-efficient of variation and average total daily insulin.

RESULTS

The cohort comprised 53 adults (64% women, 64% AID), totaling 74 vaccination periods (84% Pfizer-BioNTech boosters), mean ± SD age 40.0 ± 15.9 years, duration of diabetes 26.0 ± 15.4 years. There was no significant difference between pre-vaccination TIR (61.0%±18.5) versus 3 (60.5%±22.8) and 7 days post-vaccination (60.2%±21.8; p = 0.79). Level 1 hypoglycemia, time in range 54-69 mg/dL, was lower 3 (1.1%±1.7) and 7 days post-vaccination (1.1%±1.6), compared with 14 days pre-vaccination (1.4%±1.4; p = 0.021).

CONCLUSION

The study provides evidence that SARS-CoV-2 booster vaccination does not acutely worsen glycemia in people with T1D receiving insulin pump therapy.

Metabolic and Clinical Outcomes in Type 1 Diabetes in the COVID-19 Pre- and Post-Vaccination Periods in Spain: The COVID-SED1 Study

Aims: To evaluate the metabolic and clinical outcomes in the Spanish type 1 diabetes mellitus (T1D) population before and after COVID-19 vaccination. Methods: A retrospective observational study was carried out in Spanish public hospitals previously enrolled in the SED1 study. Adults and children with T1D were included and their clinical electronic records were reviewed. Clinical, laboratory, and glucometric parameters from continuous glucose monitoring (CGM) data corresponding to the periods before and after administering the first COVID-19 vaccination were analyzed. Results: A total of 26 centers and 228 patients participated in this new phase of the SED1 study and 187 were finally evaluable (mean age 37.5 ± 15.6 years, 56.7% women). Overall, 94.6% of the sample was vaccinated, and this percentage increased with higher levels of education (p-value = 0.027). In the pre- and post-vaccination periods, respectively, the number of patients with acute hyperglycemic decompensation was 6/161 (3.7%) and 7/161 (4.3%) (p = 1) and with acute hypoglycemic decompensation was 6/161 (3.7%) and 6/161 (3.7%) (p = 1). The HbA1c level was lower in the post-vaccination period(mean ± SD, mg/dL): pre-vaccination 7.4 ± 0.9; post-vaccination 7.2 ± 1.0, (-0.19; p-value = 0.0006). A total of 31.9% of patients (95% CI: 24.7-39.7) in the pre-vaccination period and 45.0% (IC95%: 37.1-53.1) in the post-vaccine period had HbA1c < 7% (p-value < 0.001). Glucometrics from CGM data also showed numerical improvements post-vaccination. Conclusions: The COVID-19 vaccination was highly accepted in the Spanish T1D population, with hesitancy about the COVID-19 vaccine being higher in those with lower educational levels. A mildly better glycemic control was observed in the post-vaccination period.