Table 3.
Outcomes of the included studies in DM patients vs. patients without DM.
| Study (Author, year) | Seroconversion in patients with DM | Seroconversion in controls | Study findings |
|---|---|---|---|
| Ali,H. et al, 2021 (43) | Mean IgG: 138 (59.4) IgM: 58.1 (112) Neutralizing antibodies %: 79.7 (19.5) |
Mean IgG: 154 (49.1) IgM: 65.6 (84.2) Neutralizing antibodies%: 87.1 (11.6) |
Both SARS-CoV-2 IgG and neutralizing antibodies titers were significantly lower in people with T2DM compared to those without. Whereas no statistical significance was found between seroconversion and age, gender, obesity, and hypertension. |
| Alqassieh, R. et al, 2021 (28) | Percentage of positive seroconversion IgG: 84.2% |
NA | More than 50% of participants with negative seroconversion were diabetics. Despite of the diminishing impact of diabetes mellitus on IgG levels, this effect was not statically significant. |
| Güzel et al, 2021 (29) | NA | NA | people with DM had significantly lower antibody response levels compared with those without DM |
| Guzmán-Martínez, O. et al, 2021 (30) | Mean S1 IgG indices BNT162b2: 6.93 Ad5-nCoV: 2.86 |
Mean S1 IgG indices BNT162b2: 8.25 Ad5-nCoV: 4.26 |
No statistical significance was found between generation of S1 IgG antibodies and diabetes. |
| Lustig et al, 2021 (37) | NA | NA | IgG and detectable IgA antibody levels were lower in patients with DM (OR: 0.92; 95% CI: 0·39–2·19; p = 0·855) And OR: 0.30; 95% CI: 0.13–0.73; p = 0.008 respectively). The rate of positive neutralization was not significantly lower in individuals with DM compared to those without (OR: 0.53; 95% CI: 0·21–1·30; p = 0·166). Endpoint regression analysis demonstrate lower antibody response in diabetes group. (ratios of means of IgG and neutralizing antibody titers 3 weeks after the first dose:1·03 (0·80–1·32) and 0·83 (0·50–1·38), respectively. And at 3-5 weeks for IgG and 3-4 weeks for neutralizing antibodies: 0·84 (0·62–1·14) and 0·70 (0·38–1·28), respectively.) |
| Nomura,Y. et al, 2021 (33) | Antibody titer, Median: 382 |
Antibody titer, Median: 767 |
Diabetes mellitus was significantly associated with a lower antibody titer. |
| Saure et al, 2021 (39) | Seropositivity: After 1st dose of Sinovac: 17.3% pfizer: 40.5% 4 weeks after 2nd dose sinovac:58.0% pfizer: 89.3 8 weeks after 2nd dose sinovac:60% pfizer: 92.5% |
NA | Diabetes was related to low seropositivity among CoronaVac recipients. |
| Singh A. K. et al, 2021 (34) | Percentage of positive seroconversion; First dose: 73.7% |
Percentage of positive seroconversion; First dose : 80% |
People with T2DM had a significantly lower seropositivity rate compared to those without. |
| Percentage of positive seroconversion; Second dose : 96.1 |
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| Van Praet et al,2021 (41) | NA | NA | A significant association between diabetes and reduced cellular response has been found (Estimate 95% CI= −0.297 (−0.515 to −0.079) and P Value= 0.008). However, diabetes had no significantly effect on humoral response (P Value= 0.135) |
| Watanabe et al, 2021 (42) | NA | NA | No statistical significance was found between anti-SARS- CoV-2 antibody titer and diabetes. (p=0.876) |
| Karamese, M. et al, 2022 (31) | NA | NA | The participants with diabetes had significantly lower antibody responses vs those without. |
| Marfella, R. et al, 2022 (32) | NA | NA | Neutralizing antibodies and antigen-specific CD4+ T-cell responses were reported in this study, 21 and 52 days after the second vaccine dose. |
| Papadokostaki, E. et al, 2022 (38) | Anti-SARS-CoV-2 RBD IgG titers in AU/mL Geometric mean (95% confidence intervals); At 21 days after the first dose: 220.10 (122.59, 395.17) At 7–15 days after the second dose: 5300.64 (3868.71, 7262.56) At 70–75 days after the second: 1246.77 (853.76, 1859.89) |
Anti-SARS-CoV-2 RBD IgG titers in AU/mL Geometric mean (95% confidence intervals); At 21 days after the first dose: 354.62 (268.34, 468.65) At 7–15 days after the second dose: 6281.32 (5244.47, 7523.16) At 70–75 days after the second: 1677.94 (1412.94, 1991.53) |
Seventeen percent of participants with DM had inadequate humoral immune response after the first dose; however, after the second dose both participants with and without DM developed high and similar seroconversion. |
| Sourij C. et al, 2022 (35) | Percentage of positive seroconversion; First dose: T1DM: 52.7 T2DM: 48 Percentage of positive seroconversion after second dose was similar to first dose. |
NA | Higher antibodies levels had been reported among T1DM patients in comparison to non-diabetics and T2DM patients, 14 to 21 days after the second dose. |
| Tawinprai et al, 2022 (40) | NA | NA | Participants with diabetes had 55% (95%CI; 23%-84%) lower anti-RBD antibodies level. |
| Terpos, E. et al, 2022 (27) | NA | NA | At the day after the second dose, comorbidities like diabetes, cardiovascular problems, and autoimmune diseases had negative impact on neutralizing antibody levels; however, the effect of diabetes on low seroconversion was statistically more than others. |
NA, not available.