New finding may improve type-2 diabetes treatment in India: Lancet study

Scientists have found genetic similarities and differences between various forms of type 2 diabetes in India and Europe, an advance that they say can be used to improve the treatment of the disease in the country.

Researchers in Sweden have previously shown that diabetes can be divided into five subgroups, and that there are genetic differences between the four subgroups relating to type 2 diabetes.

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The new study, published in The Lancet Regional Health—Southeast Asia journal, confirms that the classification system is applicable on a group in western India.

"The study highlights genetic similarities and differences between different forms of type 2 diabetes in India and Europe," said Rashmi Prasad, associate professor in genomics, diabetes, and endocrinology at Lund University in Sweden.

"We see this as an exciting new step towards a better understanding of the development of type 2 diabetes in India," Prasad said in a statement.

The results are based on clinical data from 2,217 patients and genome-wide associations studies (GWAS) and a genetic risk score analysis (GRS) on 821 people with type 2 diabetes from a study in western India.

"The characteristics of all the subgroups reflected those seen in European people with diabetes. We could also confirm our previous findings that have shown that a certain form of type 2 diabetes that is characterised by relatively low BMI is the most common form of the disease in India," said Prasad.

The subgroup is called severe insulin-deficient diabetes (SIDD) and this is a form of type 2 diabetes that is also characterised by early onset, low insulin secretion, and poor metabolic control, the researchers said.

Of all the participants with type 2 diabetes in the Indian study, 47 per cent were classified as belonging to the SIDD group.

Previous studies on populations in Sweden have shown that mild age-related diabetes (MARD), which is characterized by late onset, is the most common form of diabetes among Swedish people.

"Early life undernutrition in Indians may be a major contribution to early onset of type 2 diabetes, and this may be why we see this difference in the distribution of patients between Sweden and India," Prasad said.

"The knowledge may be used to prevent the disease in India, which has the second highest number of diabetes worldwide after China. Our findings suggests that efforts to prevent malnutrition in Indians may also prevent type 2 diabetes," she added.

The second largest group in India was mild obesity-related diabetes (MOD), a group which is characterized by obesity, early onset, and a relatively mild disease progression, according to the study.

The Indian participants in the MOD group were associated with genetic variants for vitamin B12 deficiency, and this was not seen in the Swedish group of people, the researchers said.

"It's an interesting example of genetic differences between the Indian and Swedish groups in our study. This finding suggests that the causes of the disease differ between the two populations. Vitamin B12 deficiency may be a factor that drives the disease in the Indian MOD group," Prasad added.