Glycated hemoglobin level dynamics in COVID-19 survivors: 12 months follow-up study after discharge from hospital

Abstract

Introduction One of the stages of reproduction of SARS-CoV-2 is the S-protein glycosylation to facilitate penetration into target cells. It has been suggested that SARS-CoV-2 is able to enter erythrocytes, interact with heme and porphyrin, which could influence HbA1c levels. Assessment of HbA1c levels in individuals with acute COVID-19 and after recovery may show clinical relevance of this hypothesis. Aim To assess HbA1c levels in patients with COVID-19 in the acute phase and in early (6–8 weeks) and late (52±2 weeks) periods after recovery. Materials and methods We conducted a multicenter prospective study, which included patients hospitalized in Endocrinology Research Centre and the City Clinical Hospital № 52" diagnosed with COVID-19, virus identified/ not identified. Patients were divided into three groups according to baseline HbA1c level and the presence or absence of previous history of diabetes previous history of diabetes mellitus (DM): HbA1c ≤ 6.0%, HbA1c > 6.0% and patients with DM. Patients were examined during the acute COVID-19 phase and in early (6–8 weeks) and late (52±2 weeks) periods after recovery. Oral glucose tolerance test was performed in the group with initial HbA1c > 6.0% to clarify the diagnosis. Results We included 194 patients in the study. During the follow-up, 52 patients were examined in 6–8 week period: 7 with HbA1c ≤ 6.0%, 34 with HbA1c > 6.0%, 11—with previously diagnosed DM. Carbohydrate metabolism assessment in the later stages (52±2 weeks) after recovery was performed in 78 patients: 33 patients with HbA1c ≤ 6.0%, 36 patients with HbA1c > 6.0% and 9 patients with previously established diabetes. HbA1c median in patients with HbA1c ≤ 6.0% was 5.7% [5.3;5.8], with HbA1c>6.0% -6.4% [6.2; 6.6], with previously diagnosed DM—7.7% [7.2; 8.9]. Statistically significant decrease in HbA1c over time 6–8 weeks after extracts were obtained in both groups of individuals without a history of DM (Wilcoxon test, p<0.05). After 52±2 weeks we observed HbA1c decrease in all three groups (Fridman test, p<0.05): in patients with HbA1c ≤ 6.0% median HbA1c was 5.5[5.3;5.7], with HbA1c>6.0% - 6.1[6.15;6.54], with previously diagnosed DM—7.8 [5.83; 8.08]. Development of DM after 52±2 weeks was recorded in 7.24% of all examined patients without a history of DM, which is 16.6% of the total number of patients examined in dynamics with HbA1c > 6.0%. Conclusion HbA1c elevation during the acute phase of COVID-19 may be false due to the effect of SARS-CoV-2 on hemoglobin kinetics and/or detection on the surface of the SARS-CoV-2 virion highly glycosylated S-proteins by high performance liquid chromatography determinations. Upon detection HbA1c > 6.0% in patients with COVID-19 in the active phase of the disease without concomitant hyperglycemia re-determine the level of HbA1c after recovery is recommended.