Objectives: This study aimed to evaluate  manifestations of COVID-19 infection in patients of  raised fasting blood glucose (FBG) level without preexisting diabetes mellitus.

Methods: This study comparatively evaluate the  difference between patients of raised FBG level and  normal FBG level for COVID-19 manifestations by  enrolling 2750 admitted COVID-19 patients. Patients  were categorized into two Groups, where Group 1  had patients with raised FBG level (=126 mg/dL) and  Group 2 had patients with normal FBG level (<126  mg/dL). Information regarding clinical symptoms,  past medical history, laboratory feature, treatment  and outcome was extracted from medical records to  compare among both the Groups.

Results: COVID-19 patients with raised FBG  level were found to be have severe symptomatic  presentation, raised inflammatory markers and  hypercoagulable state. Total white cell count, NLR  (Neutrophil to Lymphocyte ratio), serum level of IL-6  (Interleukin-6), FDP and D-dimer were found to be  significantly higher (p<0.05) in case of raised FBG  level as compared to normal FBG level. Radiological  findings detected by chest radiograph and computed  tomography chest suggested severe lung involvement  in patients of raised FBG level. COVID-19 patients  with raised FBG level required intensive supportive  treatment as compared to patients of normal FBG  level in terms of ICU care (p=0.0033), non-invasive  ventilation (p=0.0323) and invasive ventilation  (p=0.0455). Patients with raised FBG level had  higher mortality (p=0.0178) and required prolonged   hospitalization (p=0.0008) as compared to patients of  normal FBG level.

Conclusion: FBG >126 mg/dL at admission without  pre-existing diabetes mellitus, should be considered  a risk factor for higher susceptibility of COVID-19  infection and severity by clinical presentation,  inflammatory storm, pulmonary invasion,  requirement of more intensive treatment and a poor  outcome.