Introduction: The SARS-CoV-19 pandemic affected the whole world, with a particularly high and severe incidence in patients with co-morbidities such as type 2 diabetes (T2DM). The SARS-CoV-2 variants, Delta and Omicron, posed an additional challenge in the management of these patients because of their virulence and high transmissibility. Objective: To assess the disturbance of certain biomarkers in COVID-19-positive T2DM patients in Pointe-Noire. Methods: We performed a descriptive cross-sectional study on a cohort of 206 type 2 diabetic patients affected by COVID-19. Blood samples were taken for analysis of biomarkers (CBC, ESR, CRP, GLY, and HbA1c, lipid profile, urea and creatinine). RNA was extracted from nasopharyngeal samples and PCR was performed to determine the presence of Delta and Omicron variants. Results: The mean age of our patients was 56.33 ± 12 years. The Delta variant was the most common 132 (64.08%), followed by the other variants 57 (27.67%) and Omicron 17 (8.25%). We observed significant disturbances (p<0.05) in biomarkers as a function of Delta and Omicron variants concerning: TC, TG, HDL, LDL, DDI, VS, CRP, GLY, and HbA1c. Conclusion: We identified the Delta variant as the most frequent in the diabetic population studied. Almost all biological markers studied were disrupted during COVID-19 infection in the type 2 diabetic population.