Adipose tissue inflammation and the regulation of muscle mass

This study is looking for healthy volunteers from two age groups: younger adults aged 20-30 years and older adults aged 65-75 years. Both men and women can take part. To join, you need to be able to understand the study and agree to participate, and be willing to continue your usual diet, exercise, and medications throughout the study.

However, there are some reasons why you might not be able to join. For example, if you live in a care home, or have certain serious ongoing health conditions that aren't well controlled, such as unstable heart or kidney problems, or if you have diagnosed diabetes or an autoimmune condition. You also can't take part if you have a history of cancer that needed body-wide treatment, or very high blood pressure.

Other reasons for not being able to participate include using tobacco or recreational drugs, recent changes to certain medications, regular heavy resistance exercise, very high levels of intense exercise, or if your body fat levels are outside a certain healthy range. You also can't join if you have a known bad reaction to anaesthetics like lidocaine, or if you take warfarin.

If you decide to take part, the study involves several visits to the University of Bath and, for older participants, an extra visit to the University of Exeter. You'll have two visits to Bath. The first visit includes filling out questionnaires, having body scans (to see your muscle, fat, and bone density), and checks of your thinking skills, physical fitness, and how your body uses energy. You’ll also do a short walk on a treadmill. You'll be given diaries for food and sleep, and a device to wear that tracks your physical activity between visits. You'll be asked to maintain your normal daily routine during this time.

The second visit in Bath involves taking two small fat samples from your tummy area. A small, thin tube (cannula) will also be placed in a vein in your arm to take regular blood samples throughout the visit. You'll also drink a sugary drink to check your blood sugar levels. For younger participants, this second visit is the end of their involvement.

Older participants will have a third visit to the University of Exeter. Here, we'll look at how your muscles respond to exercise and food. This involves resting, doing some gentle resistance exercises, and then drinking a protein shake. During this visit, two thin tubes (cannulas) will be placed: one in your arm to give you a special protein "tracer" that helps us measure muscle changes, and one in your hand for taking more blood samples. We'll also take four small muscle samples from your thigh muscle (two from each leg). You'll be reimbursed for travel, given parking permits, and receive gift vouchers for your time. At the end, you'll get your results and personalised feedback on diet, activity, blood pressure, body composition, and thinking skills. If anything unexpected comes up, we'll let you know and suggest you see your GP.