COVID can target human pancreas. Following a Covid-19 infection, reduced numbers of insulin secretory granules in beta cells and impaired glucose-stimulated insulin secretion have been observed.
Further, after the COVID-19 disease, some patients developed insulin resistance and had elevated blood glucose levels although they had no previous history of diabetes.
SARS-CoV-2 infection may lead to a strong release of pro-inflammatory signalling substances (cytokines). Activation of the immune system may persist for months after a SARS-CoV-2 infection and impair insulin effectiveness (muscle, fat cells, liver).
However, it was unclear whether these metabolic changes are transient or whether Covid-19 disease increases the risk of persisting diabetes.