Table 1.

Reasons of increased severity of COVID-19 in diabetes based on various studies (mostly unadjusted analyses).

Established

(1) Glycaemic instability: hyperglycaemia and possibly hypoglycaemia

(2) Immune defects especially impaired T-cell response

(3) Associated comorbidities like obesity, heart and kidney diseases

Postulated

(1) Chronic subclinical inflammation, increased interleukin 6

(2) Increased plasmin

(3) Reduced ACE2

(4) Increased furin (involved in entry of virus into cell)