The whole world has been shaken by the COVID-19 pandemic. Scientists working in different fields such as epidemiology, virology and immunology are struggling to find the remedy to control and prevent this epidemic. A number of theories are going around about the cause and effect of this virus on human beings. The protective role of small pox and BCG vaccination from COVID-19 is also being analysed.
Morbidity and mortality due to COVID-19 is high in those with co-morbid conditions including Diabetes.
Type 2 diabetes is associated with low grade chronic inflammation induced by the excessive visceral adipose tissue (belly fat). Persistent hyperglycemia ( high blood sugar ) and inflammation can cause ineffective immune response resulting in decreased defense mechanism against any infection.
As a consequence, uncontrolled diabetes along with advanced age is a major factor of poor outcome during an infection with COVID-19.
Recently a ray of hope has appeared in the usefulness of the class of drug, DPP-4 inhibitors. DPP-4 inhibitors are used to control blood sugar levels and widely used in the treatment of Type 2 Diabetes.
We need to know the function of DPP-4 to understand the role of DPP-4 inhibitor. DPP-4 is a type 2 transmembrane glycoprotein expressed in many tissues including immune cells. Although its functions are not fully understood, it plays a role in post meal glucose regulation.
DPP-4 expression is high in visceral adipose tissues and increases inflammation and insulin resistance.
In a simple way we can now understand a drug that inhibits DPP-4 will reduce blood sugar, reduce insulin resistance and reduce inflammation.
Coming to COVID-19, excessive inflammatory response after an infection has been shown to be the major cause of an adverse outcome including acute respiratory distress syndrome and acute kidney injury. So harnessing the protective role of DPP-4 inhibitor in decreasing the profound inflammation seems logical.
Few studies published on the anti–inflammatory protective role of DPP-4 inhibitors in diabetic mice with MERS –CoV infection support this concept. A meta analysis in human beings also showed that upper respiratory tract infection does not increase significantly with DPP-4 inhibitors treatment.
It concluded that DPP-4 inhibitors have been associated with anti inflammatory and anti adipogenic effect.
We need more data on the anti-inflammatory effect of DPP-4 inhibitors in minimising the risk and the progression of acute respiratory complications in COVID-19 patients with Type 2 Diabetes.
