Prevaccination Glucose Time in Range Correlates With Antibody Response to SARS-CoV-2 Vaccine in Type 1 Diabetes.

CONTEXT: Poor glucose control has been associated with increased mortality in COVID-19 patients with type 1 diabetes (T1D). OBJECTIVE: This work aimed to assess the effect of prevaccination glucose control on antibody response to the SARS-CoV-2 vaccine BNT162b2 in T1D. METHODS: We studied 26 patients with T1D scheduled to receive 2 doses, 21 days apart, of BNT162b2, followed prospectively for 6 months with regular evaluation of SARS-CoV-2 antibodies and glucose control. Immunoglobulin G (IgG) to spike glycoprotein were assessed by enzyme-linked immunosorbent assay, and serum neutralization by a live SARS-CoV-2 assay (Vero E6 cells system). Glycated hemoglobin A1c (HbA1c) and continuous glucose monitoring (CGM), including time in range (TIR) and above range (TAR), were collected. The primary exposure and outcome measures were prevaccination glucose control, and antibody response after vaccination, respectively. RESULTS: Prevaccination HbA1c was unrelated to postvaccine spike IgG (r = -0.33; P = .14). Of note, the CGM profile collected during the 2 weeks preceding BNT162b2 administration correlated with postvaccine IgG response (TIR: r = 0.75; P = .02; TAR: r = -0.81; P = .008). Patients meeting the recommended prevaccination glucose targets of TIR (≥ 70%) and TAR (≤ 25%) developed stronger neutralizing antibody titers (P < .0001 and P = .008, respectively), regardless of HbA1c. Glucose control along the study time frame was also associated with IgG response during follow-up (TIR: r = 0.93; P < .0001; TAR: r = -0.84; P < .0001). CONCLUSION: In T1D, glucose profile during the 2 weeks preceding vaccination is associated with stronger spike antibody binding and neutralization, highlighting a role for well-controlled blood glucose in vaccination efficacy.

Impact of Third Dose COVID-Vaccination on Glycaemic Control in Individuals with Type 1 Diabetes Using Flash Glucose Monitoring

Background: Coronavirus (COVID-19) disease portends a poor prognosis in patients with type 1 diabetes (T1D) . As a consequence, the booster dose of Covid-vaccination should be prioritized in these patients. Nonetheless, concerns exist about vaccine-induced dysglycemia. Objectives: Aim of this study was to assess the short-term effects of booster dose of Covid-vaccination on glycaemic control assessed by flash glucose monitoring (FGM) in people with T1D. Methods: In this observational cross-sectional study we investigated changes in daily insulin requirement (IR) and glycaemic control between 7 days before and 7 days after the third dose of vaccination with BioNTech Pfizer among 30 individuals with T1D on multiple daily insulin injections wearing a flash glucose monitoring (FGM) device. The following parameters of glycaemic variability were analysed: mean glucose, time in range (TIR) , time above range (TAR) , time below range (TBR) and coefficient of variation (CV) . Results: No significant differences were found for mean glycemia, TIR, TAR and TBR over the course of the vaccination from 7 days prior to receiving the third-dose vaccination until 7 days after. Nonetheless, CV and IR were significantly higher (CV, p-value = 0.001;IR, p-value = 0.05) in the week after the vaccination compared to the week earlier. The median value of CV was 35.5% [33-37] before and 36.9% [34-39] after the booster dose, whereas the median value of IR changed from 0.55 UI/Kg/day to 0.61 UI/Kg/day. Conclusions: Our study suggests that the booster dose of Covid-vaccination impact on glycaemic variability and insulin requirement in people with T1D, probably due to the pro-inflammatory cytokines and immune responses. While this observation should be investigated in larger studies, potential glycaemic aberrations in response to Covid-immunization should be considered by health care professionals and glucose monitoring intensified within the days around the vaccination.

Effects of the COVID-19 lockdown on glycaemic control in subjects with type 2 diabetes: the glycalock study.

AIM: To assess the effect of the coronavirus disease 2019 (COVID-19) lockdown on glycaemic control in subjects with type 2 diabetes (T2D). MATERIALS AND METHODS: In this observational, multicentre, retrospective study conducted in the Lazio region, Italy, we compared the differences in the HbA1c levels of 141 subjects with T2D exposed to lockdown with 123 matched controls with T2D who attended the study centres 1 year before. Basal data were collected from 9 December to 9 March and follow-up data from 3 June to 10 July in 2020 for the lockdown group, and during the same timeframes in 2019 for the control groups. Changes in HbA1c (ΔHbA1c) and body mass index (ΔBMI) during lockdown were compared among patients with different psychological well-being, as evaluated by tertiles of the Psychological General Well-Being Index (PGWBS). RESULTS: No difference in ΔHbA1c was found between the lockdown and control groups (lockdown group -0.1% [-0.5%-0.3%] vs. control group -0.1% [-0.4%-0.2%]; p = .482). Also, no difference was found in ΔBMI (p = .316) or ΔGlucose (p = .538). In the lockdown group, subjects with worse PGWBS showed a worsening of HbA1c (p = .041 for the trend among PGWBS tertiles) and BMI (p = .022). CONCLUSIONS: The COVID-19 lockdown did not significantly impact glycaemic control in people with T2D. People with poor psychological well-being may experience a worsening a glycaemic control because of restrictions resulting from lockdown. These findings may aid healthcare providers in diabetes management once the second wave of COVID-19 has ended.