Novel study adds to the evidence that people with type-2 diabetes (T2D) are at greater risk of a poor outcome should they become infected with the virus that causes COVID-19. But there is some encouraging news. People with T2D whose blood sugar is well-controlled fare much better than those with more poorly controlled blood sugar. More than 500 million people around the world have T2D. While it was clear that people with this condition fare worse with COVID-19, Li and colleagues wondered what role a person's blood glucose control might have on those outcomes. To find out, they conducted a retrospective longitudinal multi-centre study including 7,337 confirmed COVID-19 cases enrolled among 19 hospitals in Hubei Province, China. Of those, 952 people had T2D and the other 6,385 did not.