A team of international researchers, including Dr Robin Walters from the Nuffield Department of Population Health (NDPH), have carried out the largest ever genetic study in non-Europeans, giving new insight into why people from East Asia seem to be more prone to type 2 diabetes than Europeans.
The new research, published in Nature, looked at genetic information from 433,540 individuals from China, Hong Kong, Japan, the Philippines, Singapore, South Korea, Taiwan and the US. Type 2 diabetes is generally thought to develop as a result of obesity, but some East Asians develop the condition despite not being obese based on their body mass index (BMI). The researchers identified 61 new genetic variants associated with type 2 diabetes in people of East Asian descent that had not previously been detected in people of European descent, which might help to explain this.
The international research team of almost 100 people was led by Dr Walters, Dr Xueling Sim at Saw Swee Hock School of Public Health, National University of Singapore, Dr Karen Mohlke at the Department of Genetics, University of North Carolina at Chapel Hill School of Medicine, Dr Bong-Jo Kim at the Center for Genome Science, National Institute of Health, South Korea, and Dr Takashi Kadowaki at the Department of Diabetes and Metabolic Diseases, University of Tokyo, Japan.
The new variants associated with type 2 diabetes in people of East Asian descent include several near to genes involved in skeletal muscle, pancreatic functions and alcohol metabolism, and in genes linked to higher levels of fat within the abdomen. They also found that some genetic signals reflect multiple influences on type 2 diabetes development, through combinations of different mechanisms in different parts of the body. For example, a gene affecting insulin production in the pancreas overlaps with a gene affecting the use of insulin in muscles.
Dr Walters, Senior Scientist in Genetic Epidemiology, led the genetic analysis of data from the China Kadoorie Biobank (CKB), which is based at NDPH. More than 20% of the total sample size included in the Nature paper came from CKB.
Dr Walters said: "The study shows how the underlying causes of type 2 diabetes are similar across the world, meaning that these major new findings in East Asian populations are potentially important globally. The discovery of new genes that are important in diabetes can help us to understand the factors that affect someone's chances of developing diabetes, and can identify possible new targets for drug treatments.
"We are really excited that CKB could be part of this significant international effort, which emphasises the value of genetic studies in ancestry groups other than Europeans. This major contribution by CKB to an important 'genome-wide association study' is - we hope - the first of many, as the last few years' hard work by the CKB genomics team begin to bear fruit."