for Adipose Tissue DIabetes VAriants (fATDIVA)

The adipose (fat) cells under the skin are where individuals store excess fat. The more excess fat they have, the more "strain" they put on these cells which then get bigger and don't work as well as they should. Having some fat under the skin is important. People who have a genetic defect which results in them having almost no fat under their skin have a very high risk of a condition called insulin resistance (where the body does not respond as well to insulin and blood sugar levels rise). This can lead to diabetes and heart disease despite them not being overweight. Scientists have only recently started to understand the importance of fat in insulin resistance and how people unable to store fat very well can have insulin resistance despite not being obese. The investigators have also recently discovered that small changes in a person's genetic code (their body's instruction manual) may also affect their ability to store fat and would like to explore this in more detail. To do this, they will recruit volunteers from the Exeter 10,000 study who gave permission to contact them about further research. The investigators will collect detailed body size measures and blood samples taken before and after a special drink that is high in fat (similar to a thick milk shake), then compare the results between people with and without the particular genetic changes of interest. Knowing more about these genetic changes and how fat cells work could help to improve understanding about why some people develop diabetes and heart disease despite a relatively normal BMI.