Type 1.5 diabetes is a slow, progressing variation of type 1 diabetes, and a term given to people who do not need insulin instantly to manage their diabetes.

The most common other name for the disease is Latent Autoimmune Diabetes in Adults (LADA), while an alternative term is late-onset type 1 diabetes.

Type 1.5 diabetes is typically diagnosed in adults who have low or no resistance to insulin. Diagnosis is common in people of normal weight, but overweight people can also develop type 1.5 diabetes.

While type 1.5 diabetes is a form of type 1 diabetes, it shares similarities with type 2 diabetes, particularly in its slower development of symptoms.

Relationship between type 1.5 and type 1 diabetes

Type 1.5 diabetes and type 1 diabetes are similar as both are characterised by the autoimmune destruction of insulin-producing beta cells.

People who develop type 1 diabetes have an immediate resistance to insulin, but those with type 1.5 diabetes can go a long time before requiring insulin.

Type 1.5 diabetes is not immediately dependent upon insulin treatment following diagnosis and some doctors and endocrinologists may withhold insulin therapy until it is strictly necessary.

Insulin will eventually be required to manage type 1.5 diabetes. However, in some cases it can take up to six years for people with type 1.5 diabetes to become dependent on insulin.

Relationship between type 1.5 and type 2 diabetes

Type 1.5 diabetes is not a form of type 2 diabetes, but misdiagnosis is common. The typical development of type 1.5 in adulthood and slow progression of the disease is often confused with type 2.

People with type 1.5 will require insulin therapy within several years, a key difference in people with type 2 diabetes.

Another difference is that unlike type 2 diabetes, type 1.5 diabetes cannot be reversed through significant weight loss.

People with type 1.5 diabetes can be overweight and display signs of insulin resistance, but it is a not a hallmark of the condition as it is often the case with type 2 diabetes.