Does Ongoing Inflammation in Recovered COVID-19 Disease Aggravates Preexistent Diabetes Mellitus or Unmasks New-onset Diabetes Mellitus? A Single-center Experience of 800 Cases at 6-month Follow-up.

Introduction: Although blood sugar abnormalities have been reported during the COVID-19 pandemic due to ongoing virus-related effects on insulin secretory effects on the pancreas and stress and steroids used during management, its long-term effects remain unknown. Real-world data on blood sugar abnormalities in follow-up with special emphasis on new-onset diabetes mellitus (DM) or unmasking ongoing DM is an issue of concern that remains underestimated and under-evaluated in clinical settings.

Methods: Prospective, observational cohort study conducted between January 2021 and December 2022 included 800 COVID-19 patients above 18 years of age, irrespective of their disease severity and comorbidity, after a valid written consent. All the study cases were followed for 6 months after discharge from the hospital. Protocolled recording of covariates such as blood sugar (fasting, postprandial, and random), HbA1c, blood pressure, anthropometric indices, electrocardiogram, lipid profile, and uric acid was done at the entry point. Documentation of indoor records such as computed tomography (CT) Severity scores into mild (score <8), moderate (score 9-15), and severe (score >15); inflammatory markers such as interleukin-6, ferritin, C-reactive protein, lactate dehydrogenase and D-dimer, and interventions used during hospitalization such as oxygen supplementation and oxygen plus BIPAP/NIV were done as a protocol. Statistical analysis was done using the Chi-square test.

Results: In the present study, blood sugar abnormalities as preexisting DM with aggravation noted in 12.75% (102/800), post-COVID-19 transient hyperglycemia in 43.75% (290/800), post-COVID-19 new-onset DM in transient group in 17.14% (60/350), post-COVID-19 new-onset DM in 8.59% (60/698) and no DM or hyperglycemia in 43.5% (348/800) cases [ P < 0.00001]. A significant association was observed between interventions used, such as oxygen and oxygen plus BIPAP/NIV requirement, and cases without interventions with blood sugar profile such as new-onset DM, preexistent DM with aggravation, post-COVID-19 transient hyperglycemia and no DM or hyperglycemia ( P < 0.00001). A significant association was observed in blood sugar level switch from normoglycemic to transient hyperglycemic to DM range during pre-COVID-19 to post-COVID-19 state in follow-up ( P < 0.00001). Covariates analysis such as age, gender, body mass index observed a significant association with cases with new-onset DM, preexistent DM with aggravation, post-COVID-19 transient hyperglycemia and no DM ( P < 0.00001). Comorbidities such as hypertension and IHD observed significant association with blood sugar profile in study cases in post-COVID-19 setting ( P < 0.00001). Inflammatory markers during hospitalization, high-resolution CT severity score, and uric acid analysis during follow-up documented significant association with new-onset DM, preexistent DM with aggravation, post-COVID-19 transient hyperglycemia and no DM or hyperglycemia during post-COVID-19 follow-up ( P < 0.00001).

Conclusions: COVID-19 has been associated with blood sugar abnormalities such as transient hyperglycemia, aggravation of underlying DM as a result of the ongoing disease process, and treatment options used during management in indoor settings. Inflammatory markers during hospitalization, interventions used during indoor period, and severity of COVID-19 illness in chest imaging have a positive association with blood sugar abnormalities. Proportionate number of transient hyperglycemia cases has evolved toward new-onset DM cases in 6-month post-COVID-19 follow-up. COVID-19 illness has played a role in unmasking new-onset DM.