Individuals with comorbidities, particularly type 2 diabetes (T2D), were considered the most vulnerable subgroup during the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome-2 (SARS-CoV-2).
recent Scientific report The study determined the role of anti-SARS-CoV-2 antibody levels in the outcome of COVID-19 in T2D patients.
Study: COVID-19 patients with type 2 diabetes: a prospective cohort study. Image credit: Ink Drop/Shutterstock.com
T2D patients account for 9.5% of severe SARS-CoV-2-infected patients and 16.8% of COVID-19-related deaths. This group of patients was more likely to require hospitalization and intensive care due to COVID-19. Several factors have been identified that increase the risk of serious infections and mortality.
Some of these factors are endothelial dysfunction, hypercoagulation due to overexpression of prothrombotic factors, decreased respiratory function, increased inflammatory cytokines, preexisting insulin resistance, and chronic disease.
Although there is a high COVID-19 vaccine coverage worldwide, few studies have determined a correlate of protection to indicate vaccination efficacy in high-risk subgroups.
As T2D patients are at high risk of severe SARS-CoV-2 infection, understanding the link between anti-SARS-CoV-2 antibody levels and COVID-19 outcome is essential.
Once this association is established, effective strategies based on booster vaccination can be devised to protect individuals belonging to this high-risk group.
About the study
The current multicenter, prospective cohort study investigated whether anti-SARS-CoV-2 spike antibodies could be used as a correlate of protection against hospitalization in T2D patients. The effect of pre-existing organ damage on anti-SARS-CoV-2 antibodies was also assessed.
For this study, participants were enrolled from five Austrian hospitals and admitted between August 1, 2021 and April 10, 2022. All participants tested positive for COVID-19 in a polymerase chain reaction (PCR)-based test
Blood samples were collected after hospital admission. Hospitalizations and out-of-period follow-ups during the study period were excluded.
Patients were classified as diabetic and given the COVID-19 vaccine. Vaccinated individuals received a single or two doses of an approved COVID-19 vaccine.
Besides diabetes, other factors that increase the risk of serious infections are age and obesity. A higher mortality risk was associated with increased prevalence of hypercoagulation, inflammation, and mechanical obstruction. Mortality rates also varied based on the virulence of the SARS-CoV-2 strain.
This study evaluated serum creatinine, anti-SARS-CoV-2 spike antibody and NT-proBNP levels.
Creatinine levels are defined as elevated when they are above 1.2 mg/dl in men and 0.9 mg/dl in women. Similarly, NTproBNP levels were considered elevated above 125 pg/ml.
1,254 hospitalized patients were screened for this study, of which 1,152 were recruited. It must be noted that anti-SARS-CoV-2-spike antibody levels were estimated for all participants, whereas NT-proBNP and creatinine were only measured for 1,046 patients due to insufficient remaining samples.
In this study cohort, 118 patients died, 165 patients required intensive care unit admission, 587 patients required supplemental oxygen, and 47 patients underwent endotracheal intubation. A total of 275 participants in the study cohort had a history of diabetes or were diagnosed during their hospital stay.
Low anti-SARS-CoV-2 spike antibody levels during hospital stay were strongly associated with higher endotracheal intubation, intensive care unit admission, higher in-hospital mortality and oxygen administration in T2D patients. The high death rate was attributed to increased hyperglycemia.
Previous studies have shown that increased glucose concentration in monocytes from T2D patients increases the expression of pro-inflammatory cytokines, which are strongly associated with the Covid-19 cytokine storm.
Consistent with the findings of this study, previous studies have indicated a higher mortality rate in diabetic patients than in non-diabetic patients. It must be noted that most T2D patients have other serious comorbidities including kidney and cardiovascular diseases.
T2D patients recruited in the present study were significantly older and with higher BMI. Furthermore, this study group demonstrated significant rates of coronary artery disease, hypertension, heart failure, renal disease, and cerebrovascular disease.
When patients were stratified based on elevated creatinine or ntproBNP levels, no significant change in mortality was observed between diabetic and matched, non-diabetic patients.
This finding indicates that diabetic patients may not be at higher mortality risk associated with COVID-19 due to diabetes alone, but due to the cumulative effect of multiple factors, including aging, prevalence of severe comorbidities, and obesity.
A higher anti-SARS-CoV-2 spike in antibody levels may reduce mortality in high-risk mortality groups due to severe SARS-CoV-2 infection. Compared to non-vaccinated patients, vaccinated T2D patients demonstrated better COVID-19 outcomes.
The present study showed that anti-SARS-CoV-2 spike antibody levels during hospitalization were inversely associated with endotracheal intubation, intensive care admission, oxygen administration, and mortality among hospitalized T2D patients with covid-19.
It also showed that T2D patients could be protected from adverse COVID-19 outcomes by providing booster vaccination based on antibody levels.