South Asians have about five times the risk of adult onset diabetes (high blood sugar) than
Europeans and nearly one in five South Asian men in the United Kingdom have the disease.
Diabetes is a serious disease that can lead to a number of adverse health consequences
including heart disease, kidney disease and blindness and accounts for about 10% of all
healthcare costs in the UK. Obesity is strongly linked to diabetes risk, but the adverse
effect of getting fatter on diabetes risk is much higher in South Asians than Europeans. The
purpose of this study is to understand why this is the case. When humans put on weight
initially this fat is stored under the skin (subcutaneous fat). This is relatively safe.
However, when the capacity of this under skin storage is exceeded, fat is stored internally
within the tummy area (visceral fat) and in organs such as the liver and muscle, which is
less safe and increases diabetes risk. Investigators think that South Asians' capacity to
store fat safely under the skin is lower than Europeans, so fat is stored internally and in
liver and muscle at lower body weights than Europeans. The purpose of this study is to
investigate whether this occurs and why. To do this investigators will compare a group of
South Asian and European men and see how gaining and losing weight affects fat storage within
the body and the function of fat cells. Investigators will also assess the effect of weight
gain and weight loss on metabolism, fitness and risk factors for diabetes and heart disease.
The study will include healthy men of normal weight aged between 18-45 year and of either
white European or South Asian (both parent of Indian, Pakistani, Bangladesh or Sri Lankan
origin) ethnic origin.
Body weight will be altered by initially gaining weight and then losing weight. To do this
participants will initially have to eat more food for 4-6 weeks and then go on a diet
combined with exercise for 12 weeks. Participation in the study will last around 5½ months in
total.
During the study pictures of body fat stores will be taken using an MRI scanner, a
biopsy/sample of tummy fat will be taken to look at the fat cells and physical fitness and
body metabolism (the way the body deals with sugar, insulin and fat) will be measured. These
measurements will be done at three different times: before gaining weight, once weight is
gained, and after losing weight (and back to original weight). The measurements will give a
detailed assessment of the changes in the body when gaining or losing weight.
The benefits of taking part in the study are receiving detailed feedback about fitness
levels, body fat, dietary intake, blood pressure, cholesterol, blood sugar and level of
"insulin resistance". Feedback about the overall study findings will also be provided.
In addition, the knowledge gained from participation may benefit people who are at risk of
diabetes in the future by increasing our understanding of why South Asians are at increased
risk of developing diabetes. It will also help guide future research investigating how to
reduce this increased risk through lifestyle changes and may also help direct the development
of medicines to prevent and treat diabetes groups at increased risk of the disease.
Possible disadvantages of the study are gaining 7% of body weight over 4-6 weeks. This is
likely to temporarily induce negative metabolic changes. However, investigators are also
supporting losing this weight (and hopefully more) in the weight loss phase of the study.
There is no evidence that short-term weight gain of this nature causes any long-term adverse
effects. Longer-term weight gain however is associated with an increased risk of diabetes,
cardiovascular disease and high blood pressure. It is therefore important that investigators
ensure participants return to original weight at the start of the study. Taking fat biopsies
carries a small risk of minor bruising or an infection. Good sterile practice reduces this
risk of infection and application of ice and pressure to the biopsy site reduces the risk of
bruising. Blood sampling via the cannula may cause minor bruising or an inflammation of the
vein. Some participants may feel faint when they give blood. One of the exercise tests will
be at a maximal level and the possibility exists that, very occasionally, certain changes may
occur during or shortly after the test. They include abnormal blood pressure, fainting or a
change in the normal rhythm of the heartbeat. There is a small possibility that taking part
in this study will reveal a health problem that patients already have such as high
cholesterol or high blood pressure. If such a problem is revealed, investigators will ask
permission to inform the participant's General Practitioner to receive clinically appropriate
follow-up care.
This study is running for ~2.5 years from March 2015 and is based at the University of
Glasgow. The study is being funded by the European Commission as part of the European Medical
Information Framework (EMIF), called EMIF-Metabolic. This research will help investigators to
better predict who is likely to be at risk of developing diseases such as diabetes and to
develop new medicines to prevent and treat these diseases. More details about EMIF-Metabolic
are available here: http://www.emif.eu/emif-meta/objectives.
