Unique clusters of type 2 diabetes identified in Indians

Researchers have identified distinct forms of type 2 diabetes unique to Asian Indians which could have implications for managing the disease.

Scientists said that Type 2 diabetes in Asian Indians, referred to as the “Asian Indian Phenotype”, differs from that in white Caucasians in a number of significant ways, however the majority of knowledge surrounding diabetes and its cardiovascular complications has been accumulated from studying white populations with Western European ancestry.

In the latest study, led by the University of Dundee’s Inspired project, researchers found that type 2 diabetes in Asian Indians can be classified into four distinct phenotypic clusters.

While two of the clusters correspond to clusters identified in the European populations, the other two are novel sub-groups unique to Asian Indians.

The Asian Indian Phenotype is characterised by high levels of abdominal fat and increased insulin resistance even at low levels of body mass index (BMI), and it has been suggested this is the main reason for increased propensity to develop type 2 diabetes at younger age.

Researchers said classifying Asian Indians with type 2 diabetes into phenotypic clusters could help in predicting the risk of complications and in focusing more attention on individuals with the highest risk of developing these.

Professor Colin Palmer, of the University of Dundee’s School of Medicine, said: “These findings appear to be unique to Indians as they differ significantly from the findings published earlier in the European population.

“We recently reported that Asians respond better to DPP4 inhibitors and SGLT2 inhibitors.

“The findings of this study confirm the greater insulin secretory defect and the younger age at onset of diabetes in South Asians.”

Inspired seeks to improve diabetes outcomes in India by working to better understand who gets diabetes, how it progresses, why some people respond better than others to treatments, and why some patients develop complications.

The university said the project sees Dundee’s expertise in the use of medical records to deliver improved care in diabetes “twinned” with the large patient data set (covering more than 450,000 Indian patients) collected by Dr Mohan’s Diabetes Specialities Centres, the largest clinical network of diabetes care in India.

The four clusters identified in the study are Severe Insulin Deficient Diabetes (SIDD), Insulin Resistant Obese Diabetes (IROD), Combined Insulin Resistant and Deficient Diabetes (CIRDD) and Mild Age-Related Diabetes (MARD).

SIDD and MARD correspond to the clusters identified in the Europeans populations, while the other two are novel sub-groups unique to the Asian Indian population.

Researchers said CIRDD is of particular importance as it is characterised by difficult-to-control hyperglycemia and increased risk of both diabetes eye and kidney disease.

Lead author Dr Viswanathan Mohan, chairman of Dr Mohan’s Diabetes Specialities Centre and President of Madras Diabetes Research Foundation, said: “These subgroups of type 2 diabetes have implications as far as treatment is concerned and the choice of anti-diabetic drugs.”

The study is published in BMJ Open Diabetes Research and Care.

The research was funded by the National Institute for Health Research.