Diabetes may actually be of five types and not just type 1 and type 2 as people know it, suggests new research published in The Lancet Diabetes & Endocrinology journal.
Recasting adult-onset diabetes into five types could help better tailor early treatment for patients, said the research by scientists from Lund University Diabetes Centre, Sweden, and Institute for Molecular Medicine Finland. The five types found had different characteristics, with different complications, and called for different treatment needs.
According to WHO estimates, India has about 70 million diabetics and is rapidly moving towards becoming the diabetes capital of the world, even though rates of the disease are increasing across the world.
While type 1 diabetes is generally diagnosed in childhood and caused by the body not producing enough insulin, type 2 occurs when the body cannot produce enough insulin to meet increased demand imposed by obesity and insulin resistance (dearth of hormone receptors), and typically occurs later in life. Most diagnosed cases are type 2 (75-85%).
For the new study, in 14,775 patients across Sweden and Finland, the authors analysed six measurements — age at diagnosis, body mass index, long-term glycaemic control, successful functioning of insulin-producing cells in the pancreas, insulin resistance, and presence of auto-antibodies associated with autoimmune diabetes. They also did genetic analyses, and compared disease progression, treatment, and development of complications for each type.
The authors identified one autoimmune type of diabetes (condition in which the body produced chemicals that destroyed insulin) and four distinct subtypes of type 2 diabetes. Three forms were severe and two mild. Among the severe forms, one group had severe insulin resistance and a significantly higher risk of kidney disease than the other types (affecting 11-17% of patients). Another had relatively young, insulin-deficient individuals with poor metabolic control but no auto-antibodies (9-20%). The remaining severe group was insulin-deficient patients who had auto-antibodies associated with autoimmune diabetes (6-15%), the form called type-1, or latent autoimmune diabetes in adults.
The most common was one of the more moderate forms, seen in the elderly and affecting 39-47% of the patients. The other mild form was mainly seen in obese individuals and affected 18-23% of patients.
All five types were genetically distinct.
“Evidence suggests that early treatment for diabetes is crucial to prevent life-shortening complications. More accurately diagnosing diabetes could give us valuable insights into how it will develop over time, allowing us to predict and treat complications before they develop,” said lead author Professor Leif Groop, Lund University Diabetes Centre . “Existing treatment guidelines are limited by the fact they respond to poor metabolic control when it has developed, but do not have the means to predict which patients will need intensified treatment. This study moves us towards a more clinically useful diagnosis, and represents an important step towards precision medicine in diabetes.”
The study could not confirm if the five types have different causes, nor if patients’ type changes over time. Future research will be needed to test and refine the five types.