New Onset Diabetes After COVID 19 (NODAC) is predominantly due to exacerbated Insulin Resistance (IR) rather than beta cell dysfunction: Lessons from tertiary care hospital data during confluence of two epidemics

To investigate determinants of new onset diabetes after COVID-19 (NODAC) and its recovery at 6 months.

This was an observational follow up study conducted from August, 2020 to July, 2023, recruiting patients with preexisting DM and COVID 19 patients with no history of DM. Multivariate regression analysis was used to determine the factors responsible for severity of COVID 19 infection in preexisting DM group. Clinical, laboratory and glycometabolic parameters were estimated at baseline and 6 months in NODAC and euglycemic group to determine the factors responsible for NODAC and its persistence at 6 months.

Of 1310 patients, 855 (65.3%) COVID 19 patients were further divided based on their glycemic status: preexisting DM (19%), NODAC (8.5%) and euglycemia (72.5%). Older age and male gender were independent risk factors for severe COVID 19 disease in patients with preexisting diabetes. Prevalence of NODAC in present study was 8.5%. Patients with NODAC had higher mean fasting blood glucose (FBG), random blood glucose (RBG) and HbA1c at baseline as compared to COVID with euglycemic group with no difference in serum C-peptide levels. Female gender, family history of DM, signs of insulin resistance, higher BMI, WHR, HbA1c, serum insulin levels, FBG and RBG predicted persistence of NODAC at 6 months.

Preexisting DM is a risk factor for severe COVID 19 disease. Patients with NODAC have evidence of persistence insulin resistance on follow up, underscoring the need for long term glycemic monitoring.