Wednesday, March 2, 2016 (ECR) – Obesity is a disease that has reached epidemic proportions around the world and affects nearly all medical disciplines. Professor Nick Finer, honorary consultant endocrinologist and bariatric physician at University College Hospital, London, will discuss how the worldwide prevalence of obesity – defined as a body mass index (weight/height² ) above 30kg/m² – has doubled between 1980 and 2008 and how modern imaging methods can be of help.
“In many ‘westernised’ countries such as the UK, Australia, Canada and the USA, more than one in three adults are obese. Children are getting fatter earlier and earlier in life too. While the mechanisms of obesity relate to energy balance: i.e. energy consumed from what we eat and drink, versus energy expended at rest and in physical activity, the causes are more complex,” Finer explains.
Obesity is strongly heritable; mutations or variations appear in many genes involved in body weight regulatory pathways, and can either result in severe childhood onset obesity – around 5% of those presenting under the age of five – or predispose to weight gain and obesity later in life. These genes can of course only drive and increase the risk of developing obesity in an environment that makes it easy to over-consume calorific foods and to remain inactive. Obesity is developing at ever earlier ages, which increases the lifetime exposure to its risks. Few organ systems are exempt from the deleterious effects of excess adiposity. Damage is increasingly linked to the secretion of hormones and chemicals from fat tissue (adipocytokines) that produce low grade inflammation locally and systemically. Type 2 diabetes, non-alcoholic fatty liver disease, cardiovascular and cancer risk, and obstructive sleep apnoea are all closely linked to obesity and the metabolic syndrome.
During the past 20 years, bariatric surgery has become an increasingly popular form of treatment for morbid obesity. The most common bariatric procedures performed include laparoscopic Roux-en-Y gastric bypass, laparoscopic adjustable gastric banding, and laparoscopic sleeve gastrectomy. Fluoroscopic upper gastrointestinal examinations and abdominal computed tomography (CT) are the major imaging tests used to evaluate patients after these various forms of bariatric surgery.
Obesity also affects medical imaging, simply due to the size of patients. Imaging equipment can be too small and sufficient imaging quality can be very hard to obtain in morbidly obese patients, especially when it comes to ultrasound.
“Obesity is now responsible for about five per cent of all deaths worldwide and the costs of obesity to society are huge. A recent report from the McKinsey organisation concluded that ‘obesity is one of the top three global social burdens generated by human beings’, equivalent in cost to smoking, or armed violence, war and terrorism. They estimated that the annual global direct economic impact and investment to mitigate obesity in 2012 amounted to £2 trillion or 3% of global GDP,” said Finer.
Body Mass Index, while useful for population studies, is not an accurate measure of total body fat, nor does it give information about fat distribution. The methodological short-comings of epidemiological studies that have suggested modest overweight may be protective, may account for the so-called ‘obesity paradox’ theory, which suggests that obese people with chronic diseases have a better chance of survival than normal-weight individuals do. “The increasing use of imaging techniques such as DXA, CT and MRI may help to resolve these issues”, said Finer.
Nicholas Finer: Honorary Clinical Professor, National Centre for Cardiovascular Prevention and Outcomes, University College London Institute of Cardiovascular Science; Honorary Consultant Endocrinologist and Bariatric Physician, UCLH Centre for Weight Loss, Metabolic and Endocrine Surgery, London, United Kingdom
Thursday, March 3, 16:00–17:30, Room D1
SF 8c Imaging in obesity
- Chairman’s introduction
S. Lee; Manchester/UK
- Epidemiology and current trends in obesity
N. Finer; London/UK
- Fat quantification and advanced body composition assessment using MRI
O. Dahlqvist Leinhard; Linkoping/SE
- Imaging of modern surgical procedures and their complications
M. Rengo; Latina/IT
- Is there a role for bariatric embolisation in the treatment of the obese patient?
C. Weiss; Baltimore, MD/US
- Panel discussion: How best to manage obesity and its implications on the radiology department