Diabetes mellitus (among other conditions) has received attention as an important comorbidity predisposing to a COVID-19 infection and its control determining prognosis from this infection. We have evaluated important associations about how diabetes mellitus (and hyperglycaemia) can affect the course of a COVID-19 infection as well as reviewing the impact of the COVID-19 pandemic on diabetic services. Existing literatures have captured aspects of the interaction of these two entities. We hope to give a vantage view for ease of knowledge.