Long-Term Anti-SARS-CoV-2 IgG Antibody Levels in Vaccinated Diabetes Patients After Recovery From COVID-19

Background

Long-term persistence of anti-SARS-CoV-2 IgG antibodies is critical to protect against SARS-CoV-2 infection or to alleviate the severity of COVID-19. However, the persistence of anti-SARS-CoV-2 IgG after infection in vaccinated diabetes patients is unclear. This study aimed to investigate levels of anti-SARS-CoV-2 IgG 1 year after SARS-CoV-2 infection in diabetes patients.

Methods

This study was conducted between December 2023 and January 2024. Participants with SARS-CoV-2 infection during December 2022 to January 2023 were included, and were classified into the diabetes group and non-diabetes group. Anti-N/S IgG antibodies were measured with chemiluminescence immunoassay.

Results

A total of 500 participants, 265 diabetes and 235 non-diabetes patients, were included. Anti-N/S IgG levels in the diabetes group were significantly lower than those in the non-diabetes group (1.92 ± 0.58 vs. 2.08 ± 0.42 log₁₀ AU/mL, p = 0.001). In vaccinated subjects, antibody levels in diabetes patients were also lower than those in non-diabetic patients. After adjustment for sex, age, body mass index, estimated glomerular filtration rate, hypertension, and heart disease, diabetes was negatively correlated with antibody titres (β = −0.16, 95% confidence interval (CI) −0.26 to −0.06, p = 0.002). In the diabetes group, after adjustment for confounders, use of sodium-glucose cotransporter-2 inhibitors (SGLT-2i) was positively associated with high antibody levels (odds ratio 3.84, 95% CI 1.70–8.65, p = 0.001).

Conclusion

Vaccinated diabetes patients have lower anti-N/S IgG antibodies than non-diabetic patients 12 months after infection. SGLT-2i is associated with higher anti-N/S IgG antibody levels in diabetes patients.