Earlier in life these beta cells were shown to exist as small clusters or as individual cells, but as we age they grow in number and mature into larger groups known as Islets of Langerhans.
The study was able to see what happened after the immune system turned against a patient’s own beta cells.
Beta cells in small clusters were picked off and destroyed so they never had the chance to mature.
Those in larger islets were still attacked, but were more durable allowing patients to still produce low levels of insulin which reduced the severity of their disease.
“I think this is a really significant finding for type 1 diabetes – this research really sheds light on why the disease is more aggressive in children,” Dr Sarah Richardson, from the University of Exeter, told the BBC.
She said “the future is much brighter” for children being diagnosed with type 1 now.
This includes the possibility of screening healthy children for the disease and of new immunotherapy drugs to delay it.
The UK has licensed teplizumab – an immunotherapy that can stop the immune system attacking beta cells and may be able to give them time to mature – although it is not available on the NHS.
“Because we have new drugs for the treatment of type 1 diabetes in children, we hope that these will be able to prevent or delay the onset in those young people,” said Dr Richardson.