Sleep Yourself To a Leaner You?
Regular readers will appreciate the rapidly accumulating body of evidence linking much of the current obesity epidemic to a rather marked reduction in sleep that has befallen us all (not least our kids). In a commentary published in the Canadian Medical Association Journal (CMAJ), Jean-Philippe Chaput and Angelo Tremblay discuss this increasing evidence pointing to a critical role of sleep (or lack thereof) in weight management. As the authors note: “Chronic sleep restriction is pervasive in modern societies, and there is robust evidence supporting the role of reduced sleep as contributing to the current obesity epidemic. New studies provide evidence that insufficient sleep enhances hedonic stimulus processing in the brain underlying the drive to consume food; thus, insufficient sleep results in increased food intake. In addition, lack of sleep has been reported to decrease plasma leptin levels, increase plasma ghrelin and cortisol levels, alter glucose homeostasis and activate the orexin system, all of which affect the control of appetite and might compromise the efficacy of dietary interventions.” Although interventions focusing on sleep are still scarce, they do discuss one randomised controlled trial in which decreased sleep (5.5 vs. 8.5 hours) together with a calorie-deficient diet resulted in amost 60% less weight loss than in the long sleepers. In another study, participants in a 6-week weight loss intervention who reported better sleep and/or sleeping at least 7 hours experienced almost 35% more weight loss than those who did not. As the authors point out: “The Canadian Obesity Network recently launched a set of practitioner tools — the 5As of Obesity Management (ask, assess, advise, agree and assist) — that highlight the importance of addressing sleep for weight management.” They recommend the use of the Pittsburg Sleep Quality Index for screening and diagnosing common sleep/wake disorders and remind clinicians that the association between inadequate sleep and obesity can also be confounded by factors such as stress, depression, psychosocial problems, chronic illness and the use of hypnotic agents. Reason enough to go well beyond ‘eat-less-move-more’ (ELMM) recommendations on obesity management. AMS Edmonton, Alberta photo credit: Michael Sissons via photo pin cc
Obesity Does Not Increase Mortality in Gastric Cancer
One of the consistent findings in the medical literature is the fact that although excess weight is associated with an increased risk for a wide range of medical problems (including the earlier onset of such complications), once people have these problems, excess weight appears to be either ‘protective’ (the so-called obesity ‘paradox’) or have little influence on long-term outcomes. Thus, a study by Kai Bickenback and colleagues from the Memorial Sloan-Kettering Cancer Center, New York, NY, published in the Annals of Surgical Oncology, failed to find an impact of obesity on long-term survival of patients with gastric (stomach) cancer. In their study, the researchers examined dat from about 1,800 patients who underwent curative intent resection for gastric carcinoma from 1985 to 2007. Overall, there was no difference in survival between overweight or obese and normal weight patients. However, overweight patients did have more proximal tumors and a lower tumor (T) stage at surgery. Overweight and obese patients also had about twice the rate of wound infections and anastomic leaks than normal weight patients. In multivariate logistic regression analyses, higher BMI, total gastrectomy, and use of neoadjuvant chemotherapy were all associated with increased wound infection and anastomotic leaks. Thus, the authors note that although peri-operative complications may be more common in overweight and obese patients undergoing surgery for gastric cancer, their survival rates are no worse than those of normal weight individuals. Obviously, given the higher peri-operative complication rates, costs for hospital stay and doctor visits may be higher in the overweight and obese patients (not analysed in this paper) – however, this should certainly not prove a barrier to providing the same care to overweight and obese patients with gastric cancer as one would to normal-weight individuals with this unfortunate condition. AMS Edmonton, Alberta photo credit: Defence Images via photo pin cc Bickenbach KA, Denton B, Gonen M, Brennan MF, Coit DG, & Strong VE (2012). Impact of Obesity on Perioperative Complications and Long-term Survival of Patients with Gastric Cancer. Annals of surgical oncology PMID: 22976377
Weekend Roundup, September 14, 2012
As not everyone may have a chance during the week to read every post, here’s a roundup of last week’s posts: Edmonton Obesity Chair, Five Years Hence Not Everything that Works Works Do Public Health Messages Promote Weight Bias? Electronic Entertainment and Communication Devices Deprive Kids of Sleep and Make Them Fat? Does Social Stigma Drive People To Bariatric Surgery? Have a great Sunday! (or what is left of it) AMS Edmonton, Alberta
Hindsight: Monocyte Activation and Adipose Tissue Inflammation
It is now well recognised that infiltration of adipose tissue with pro-inflammatory macrophages (white blood cells) is an important factor in the development of the metabolic complications of obesity. In a paper we published in HYPERTENSION in 2005, we examined the relationship between markers of macrophage activitation (DC11b) on circulating monocytes and expression of pro-inflammatory genes in adipose tissue biopsies. We also used in-vivo microdialysis to examine glucose metabolism in adipose tissue. We found that participants with higher CD11b expression on monocytes also had increased expression of the macrophage marker CD68 in adipose tissue. Although we found no differences in systemic insulin sensitivity, subjects with higher peripheral CD11b expression also showed a markedly augmented increase in dialysate glucose in adipose tissue during oral glucose tolerance testing as well as increased adipose tissue lipolysis. Thus, out data showed that human monocyte activation is associated with tissue-specific changes in glucose and lipid metabolism, which may in part be explained by monocyte/macrophage infiltration of adipose tissue. Since then, the concept of adipose tissue inflammation and its relation to metabolic complications of obesity have been well characterized and this continues to be a hot area of research. Indeed, there is now much data to support the notion that it may well be that the presence or absence of adipose tissue inflammatory response is the key defining difference between those who are considered metabolically ‘healthy’ obese and those who develop metabolic complications. AMS Edmonton, Alberta
Do Public Health Messages Promote Weight Bias?
Regular readers may recall previous posts asking whether well-meant public health messages in response to the obesity epidemic could in fact promote weight bias, thereby causing more harm than good (at least amongst the intended audience). This question has now been scientifically addressed by Rebecca Puhl and colleagues from Yale University’s Rudd Centre for Food Policy, in a paper published in the International Journal of Obesity. Puhl and colleagues collected online data from a nationally representative sample of 1014 adults, who were shown a random selection of 10 (from a total of 30) messages from major obesity public health campaigns from the United States, the United Kingdom and Australia, and were asked to rate each campaign message according to positive and negative descriptors, including whether it was stigmatizing or motivating. Participants responded most favourably to messages that were perceived to be most positive and motivating and which made no mention of the word ‘obesity’ at all, instead focusing on making healthy behavioral changes without reference to body weight. Participants also responded favorably to messages involving themes of increased fruit and vegetable consumption, and general messages involving multiple health behaviors. In contrast, messages that have been publicly criticized for their stigmatizing content (such as ‘Childhood obesity is child abuse.’, ‘Too much screen time, too much kid.’ and ‘Being fat takes the fun out of being a kid.’) received the most negative ratings and the lowest intentions to comply with message content. There were also important differences on how people of different weights perceived the stigmatizing nature of these messages: Thus, compared to non-obese participants, obese participants perceived messages like, ‘Skip seconds…Lose your gut.’, ‘You have the strength to take control of your health.’, or ‘The temptation to eat unhealthy food is hard to fight, but it’s a fight that you and your community can win.’ as significantly more stigmatizing. As the authors point out, “Despite widespread prejudice induced by societal weight stigmatization, there nevertheless remains a perception that stigmatizing obese persons will instill motivation to engage in healthier lifestyles or is necessary to raise public awareness about the seriousness of obesity….Although this perception may be common, considerable evidence demonstrates that individuals who feel stigmatized or shamed about their excess weight engage in higher calorie intake, unhealthy eating behaviors, binge-eating patterns, as well as avoidance of exercise,which can reinforce weight gain and impair weight loss. Thus, public health campaigns that communicate stigmatizing,… Read More »
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