**4. Potentials of spreading COVID-19 infection to diabetes individuals**

There is adequate evidence to say that people with diabetes at high risk get COVID – 19 infection than the general population. Diabetic patients are more likely to develop complications if they are infected with COVID 19 infection. Their condition worsens if they have other comorbidities, including coronary heart disease, above 60 years old.

Diabetic patients with COVID 19 are at high for the development of serious complications. They are most likely to suffer from moderate to severe symptoms and other complications. These symptoms and complications are less in the patients who have controlled and managed their blood glucose levels well. COVID 19 infection can cause inflammation and endothelial damage; this inflammation is responsible for generating complications in people with diabetes.

The differences in the complications results depend on viral load, host immunity, patient's age, and other long-term diseases. The mortality and morbidity rate are similar in diabetic patients with the corona infection of SARS and MERS.

Diabetic Patients with COVID 19 are at high risk for uncontrollable inflammation due to hypercoagulable response [18]. In Type 2 Diabetes, inflammation induces poor regulation in the homeostatic glucose levels and peripheral insulin sensitivity [19]. Many other factors are also responsibly increasing the severity of SARS-CoV-2 disease in diabetic patients.

## **5. Effect of diabetes on COVID-19**

Patients with diabetes are at high risk for the acquired infection of viruses and bacteria, which affect the respiratory system. The main responsible factor for this increased risk is less function of leukocytes in DM patients. Further, it increases the risk of SARS-CoV-2 inclinations in patients. The lung's deference in terms of gaseous exchange will be impaired due to microangiopathy. This mechanism causes the proliferation of the microorganism in the airway, especially SARS-CoV-2. These changes in the respiratory tract will petrogenetically affect the lung capacity and diffusing capacity of the pulmonary system [20].

Muniyappa and Gubbi concluded that the following mechanisms are responsible for causing the mortality and morbidity of SARS-CoV-2 among patients with diabetes [21].

a.Cellular binding capacity raises the entry of the virus.

b.Reduced leukocyte and the function of T- cells.

c.Vulnerability increased to high inflammation.

Studies conducted in Italy proved that ischemic heart disease and hypertension are commonly observed among patients with comorbidities. A survey conducted in Wuhan regarding the feature of COVID 19 results revealed that the prevalence of COVID 19 about 2–20% is high among the patient's DM and created the requirement of ICU admission about 7.1%. The study results on the clinical features on COVID 19 patients with diabetes reported that approximately 20% of cases reported with COVID 19 positive, and 7% of the cases required the ICU admission. In another study also similar results were observed that 17% and 12.1% accordingly [22].

Hyperglycemia plays a vital role in damaging the endothelial function, causing the cytokine storm and injuries to multiple organs. Patients with COVID 19 and hyperglycemia cause a reduced expiratory volume of the lungs. Phillips et al. [22] results revealed that high blood glucose levels in blood on the respiratory system would reduce its distinctive immune capacity. The cardiovascular mortality rate is also increased due to hyperglycemia by enhancing the inflammatory process in the endothelial system and platelet aggregation [23], in case-controlled blood glucose levels worsen the mortality rate [24].
