Ethnicity is a risk factor in people with type 1 diabetes developing kidney disease, a study suggests.

The findings also indicate that people of African-Caribbean heritage living with diabetes have nearly a 60% greater risk of advanced kidney disease.

Type 1 diabetes is an autoimmune condition that can cause symptoms early in life, while type 2 diabetes is often lifestyle-related and can develop over time.

It is estimated that 10% of people with diabetes have type 1, with 400,000 people living with the condition in the UK.

Kidney disease affects nearly 30-40% of people with diabetes, regardless of type.

Lead author Dr Janaka Karalliedde, from King’s College London, said: “Diabetes-related kidney failure is devastating for people affected and their families.

“This is the first study in type 1 diabetes to describe the impact of ethnicity on kidney function loss.

“We observed that African-Caribbean people with type 1 diabetes are at nearly 60% higher risk of losing more than half of their kidney function and that this loss also occurs faster.

“Further studies are needed to study and understand the exact reasons for this increased risk of kidney disease in African-Caribbean people with type 1 diabetes.”

Although it is known that ethnicity is a risk factor for type 2 diabetes and kidney disease, not much is known about whether ethnicity is a risk factor for kidney complications of type 1 diabetes.

Most previous studies looking at risk factors for kidney disease have been in less diverse or predominantly white people.

Researchers from King’s College London looked at more than 5,000 people with type 1 diabetes.

They all had good kidney function and 13% were African-Caribbean.

After following the group for eight years, they found that 260 people had a decline of more than 50% of kidney function and developed stage 4 kidney disease –  an indicator of severe and advanced kidney disease.

Stage 5 is kidney failure when people often need a kidney transplant or dialysis to live.

Hilary Nathan, director of policy and communications at Juvenile Diabetes Research Foundation UK, said: “This is important research, showing for the first time that people of African-Caribbean heritage have a far higher risk of developing kidney disease because of type 1 diabetes.

“This research area needs greater funding and focus to help form future approaches to genuinely personalised medicine, so that people from African-Caribbean backgrounds with type 1 diabetes do not have to face undue fear or consequences of traumatic kidney function loss.”

The study was supported by a research grant from Guy’s and St Thomas’ Hospital Charity.

The findings are published in the Diabetes Care journal.