The First International Congress on Abdominal Obesity was held in Hong Kong on January 28-30. After 5 years of activities, we, at the International Chair on Cardiometabolic Risk (ICCR), felt that the time had come to organize an international meeting devoted entirely to abdominal obesity. Indeed, despite the fact that there has been a proliferation of meetings in the areas of obesity, diabetes, lipids, hypertension, nutrition, exercise physiology, no meeting had focussed specifically on abdominal obesity while taking a multidisciplinary look which would be appealing to both basic and clinical academic scientists as well as to practicing physicians.
With the generous contribution of our academic board members and with the help of additional international experts, we were able to develop an original and unique educational program of superb quality: the International Congress of Abdominal Obesity was born and announced. As visceral (intra-abdominal) obesity and its metabolic and clinical consequences are afflicting all parts of the world, we decided to hold our first meeting in Asia in order to emphasize the fact that this part of the world will also be heavily affected by this condition. With a list of outstanding confirmed speakers, we were confident that we would have a great scientific program. However, we were anxiously awaiting the response of the scientific and medical communities. With 300 submitted abstracts and 450 participants, we got our answer: there was indeed a need for such a meeting which would take a multidisciplinary look at abdominal obesity.
The official meeting began with a session entitled “Assessment of Abdominal Obesity, Metabolic Syndrome and Related Cardiometabolic Risk”. Phil Barter opened the session by providing evidence from the large GEMS study that the low HDL cholesterol dyslipidemia is a clear feature of abdominal obesity and insulin resistance, putting into context the importance of abdominal obesity as the most prevalent form of low HDL cholesterol. Bryan Brewer followed by discussing the usefulness of the metabolic syndrome and the contribution of this concept to global cardiovascular disease (CVD) risk. He introduced the concept of cardiometabolic risk, which incorporates the additional risk driven by abdominal obesity and related features of the so-called metabolic syndrome which often results from the presence of excess visceral adipose tissue and insulin resistance. Scott Lear then followed by addressing the issue of ethnicity. He provided some key evidence that the Asian population is more prone to visceral accumulation whereas South-Asians may have more visceral fat because they have higher levels of both subcutaneous and visceral adipose tissue at any given body mass index compared to Caucasians. Takashi Kadowaki then described the key elements of an interesting comprehensive public health program focussing on the measurement of waist circumference and related features of the metabolic syndrome in Japan. We learned that such a program, called ME-TA-BO, has had a huge impact on the awareness of the Japanese population regarding the health hazards of abdominal obesity. Finally, our local host in Hong Kong, Juliana Chang, reviewed the evidence that Asians from Hong Kong were quite prone to a form of visceral obesity leading to diabetes and hypertension, increasing the risk of kidney failure. Such ethnic differences in susceptibility to the various clinical consequences of visceral obesity and the metabolic syndrome is a fascinating observation with major clinical and public health consequences and will receive further attention in our future meetings.
The next session was devoted to the “Pathophysiology of Abdominal Obesity and Related Cardiometabolic Risk”. It began with an update provided by Vincenzo Di Marzo on the contribution of the endocannabinoid system to the control of body fat distribution and ectopic fat deposition. Then, Richard Bergman discussed results from his elegant series of metabolic studies conducted on dogs which suggested that excess visceral adiposity in this model may also be associated with variations in the pulsatile lipolytic activity of the visceral fat depot, leading to particularly elevated overnight free fatty acid levels. André Tchernof then extended these observations of dog adipose tissue physiology to man with the description of a comprehensive series of studies which suggested that the excess lipolytic activity of the expanded omental depot of viscerally obese men and women could indeed play a role in the etiology of the metabolic syndrome. Marja-Riitta Taskinen then reviewed recently published and unpublished data from her laboratory suggesting that the excess liver fat accumulation observed in viscerally obese individuals was associated with an overproduction of large VLDL1 particles. Thus, in visceral obesity, excess visceral adipose tissue and liver fat could represent a “double hit” leading to a markedly deteriorated metabolic profile whereas elevated visceral adiposity in isolation would be associated with less severe metabolic abnormalities. Caroline Fox then reviewed the imaging sub-study of the Framingham Heart Study, the largest CT study published so far on the independent relationship between visceral adiposity and features of cardiometabolic risk. She also reviewed evidence that the size of other ectopic fat depots is also associated with visceral obesity and some features of the metabolic syndrome. Ulf Smith then followed by providing evidence that the inability of subcutaneous preadipocytes to differentiate in the face of an energy excess would lead to ectopic fat deposition in the liver and to the hypertrophy of visceral adipocytes which would be associated with evidence of inflammation. Thus, an “inflamed” visceral adipose tissue could, through the increased secretion of several cytokines, including interleukin-6, lead to increased systemic inflammation, insulin resistance and increased cardiometabolic risk. Jean-Pierre Després closed this session by proposing a simple approach to screen for individuals with excess visceral adiposity and with the proinflammatory, insulin resistant profile: the combination of an increased waist circumference and triglyceride levels, the so-called hypertriglyceridemic waist phenotype.
On Friday afternoon, a full session entitled “Assessment of Global Cardiometabolic Risk” was devoted to the review of relevant data from some very well-known prospective studies: Framingham (Peter Wilson), EPIC-Norfolk (Nick Wareham), Physicians and Nurse Health Studies (Frank Hu) and ARIC (Christie Ballantyne). Mark Cobain also described an approach which attempted to translate the evaluation of risk into information which would be more “palatable” for the patient. This very interesting session was beautifully introduced by a plenary lecture given by Peter Libby who put forward the notion that visceral obesity/ectopic fat was the missing link between inflammation and CVD and he made his point by reviewing a combination of classic findings and very recent cutting edge results from his laboratory.
On the next day, the whole morning session was devoted to discussion of visceral obesity from the perspectives of academic clinical scientists from various disciplines: Luc Van Gaal (diabetes), Michael Jensen (obesity), Bryan Brewer (lipidology), Arya Sharma (hypertension), Paul Poirier (cardiology), and Patrick Mathieu (heart surgery). The audience reached the conclusion that viscerally obese patients are quite prevalent across specialties. The point was made that a holistic and integrated approach will be needed to better manage these viscerally obese patients who are too often evaluated and treated in silos. The perspective of family physicians will also be sought at future meeting.
Saturday afternoon was devoted to management of abdominal obesity. The first session dealt with physical activity /exercise. A very comprehensive overview of the virtues of physical activity/exercise was provided by Robert Ross who also gave evidence that waist circumference was a better therapeutic target than body weight. This was followed by an important update on the 4-year results of an important lifestyle modification program which will be testing the hypothesis that a lifestyle modification program aiming at moderate weight loss and improvement of fitness will reduce CVD morbidity in patients with type 2 diabetes: the look-AHEAD trial which was very nicely reviewed by Donna Ryan. The session was concluded by Nick Wareham who presented a very convincing case that type 2 diabetes could indeed be prevented by improving lifestyle. He then went on to debate on the relevance of considering the development of individualized clinical approaches compared to public health preventive programs which, in his opinion, would be more effective. The issue was also raised that better approaches for the individual assessment of diabetes risk were needed which could lead to effective dual individualized and public health approaches.
Finally, the last session of the meeting was devoted to the “Nutritional Management of Abdominal Obesity”. Jean-Pierre Després first reviewed the final results of a 3-year lifestyle modification program focussing on healthy eating and physical activity/exercise: the SYNERGIE study. This was followed by a nice review given by Ronald Krauss on the potentially deleterious effects of a low fat/high carbohydrate diet on the atherogenic lipoprotein profile, suggesting that among sedentary abdominally obese individuals, one should limit the intake of carbohydrates, particularly of refined sugars. Cyrill Kendall provided evidence that one could theoretically substantially lower LDL cholesterol levels by a so-called portfolio diet which would incorporate all the beneficial components of a healthy diet. Finally, Barry Popkin shared evidence that the consumption of sugar-sweetened beverages (sodas and fruit juices) had been increasing all over the world and that this phenomenon could contribute to the epidemics of obesity. This was followed by evidence presented by Frank Hu that an increased consumption of sugar-sweetened beverages not only increased the risk of obesity but also the probabilities of developing diabetes and CVD. The audience reached the conclusion that not only we are what we eat but also what we drink.
Thus, from the positive feedback and the active participation of the audience, we feel that we have succeeded in our attempt to take, for the first time, a multidisciplinary look at a condition which affects numerous disciplines in medicine such as cardiology, diabetology, internal medicine, lipidology, hypertension, and many others which will be covered at our future meetings. Indeed, from the success of this first conference, we have decided to make it a yearly event and we proudly announce that the next meeting will be held in Buenos Aires in 2011. The core content of the meeting will be updated and completed by additional lectures and satellite meetings covering additional aspects relevant to the management of visceral obesity. For instance, we will need to better understand the development of visceral adiposity/ectopic fat over time, the genetic factors involved, its role in conditions such as sleep apnea, in lipodystorphic HIV-treated patients, in post-menopausal women, in aging, the role of sarcopenia, etc. We therefore intend to update our participants with a core content program to which we will add cutting edge findings and other topics relevant to abdominal obesity.
The landscape of modifiable risk factors for CVD has clearly changed evolving from a world of lean, hypertensive, hypercholesterolemic smokers to sedentary, viscerally obese subjects with type 2 diabetes who have a specific form of atherogenic dyslipidemia which does not include hypercholesterolemia but rather an inflammatory profile leading to insulin resistance and a plethora of diabetogenic/atherogenic metabolic abnormalities. Unfortunately, we feel that such condition is not properly assessed and managed in general and specialized medical practices. This is the ultimate goal of the ICCR and our yearly educational event will keep those interested by this updated topic and at par with cutting edge science. For those of you who were in Hong Kong, we hope that you enjoyed the meeting. For those who could not attend our conference, we hope to see you next year in Buenos Aires for an exciting second edition!