Exploring a possible link between insulin resistance, vaccine to SARS CoV 2 and glycaemic disturbances in diabetes mellitus, type 2

Abstract

The occurrence of both hyperglycaemia and hypoglycaemia, individually and in combination is reported in the literature, occurring in various insulin resistance (IR) syndromes, both to endogenous insulin, like Hirata disease, otherwise called the Insulin Autoimmune syndrome (IAS), type A, I R, Type B, IR etc. and to exogenous administered insulin, like, exogenous insulin antibody syndrome, (EIAS), non- classical auto immune syndrome to exogenous insulin, etc. Glycaemic disturbances without IR and in non-diabetics, like idiopathic and symptomatic reactive hypoglycaemias are also described in the literature. This author, recently reported for the first time, a biphasic post - vaccinal syndrome, following vaccination for Covid 19 (Covishield), causing glycemic disturbances in an elderly diabetes mellitus type 2 (DM2) patient on insulin who had moderate IR. Insulin resistance to exogenous insulin observed in the patient, is considered crucial for the occurrence of the observed clinical syndrome as, an increase or decrease of IR, and could explain the observed glycaemic disturbances. The IR to exogenous insulin, and the vaccine to Covid 19, both have immunological basis. The immunological aspects of both IR and the Covid 19 vaccine are briefly reviewed to explore any possible interaction between the two, that could explain the observed clinical syndrome, referred to above. Also, the various underlying mechanisms for the glycaemic disturbances, in the above-mentioned IR syndromes and non-IR or r syndromes are explored as to shed some light on the mechanism of the glycaemic disturbances in the syndrome reported. A hypothesis is suggested, taking into consideration, the aforesaid observations. Apart from IR to exogenous insulin, other unidentified factors that might be causing the clinical syndrome reported, and which might account for its paucity of reporting, need to be investigated by future research.