Why Obesity Is A Chronic Disease

Transcription

1 Why Obesity Is A Chronic Disease Arya M Sharma, MD, FRCP(C) Professor of Medicine Chair in Obesity Research & Management University of Alberta Edmonton, AB, Canada

2 Global Obesity Map 2014 The Lancet, 2016

3

4 Societal influences Individual psychology Food Production Food Consumption Individual activity Activity environment Biology

5 Prevalence of Obesity in Canada Twells LK, et al. CMAJ Open 2014

6 Overview/Objectives Describe the chronic nature of obesity Understand mechanisms of weight homeostasis Apply principles of chronic disease management

7

8 Recovery of Lost Weight After Diet-Induced Weight Loss (16 studies) 100 % weight regain Duration of Follow-Up Safer, So. Med. J. 84:1470, 1991

9 Successful Weight-Loss Maintainers National Weight Control Registry Limit their intake of certain foods Consume an average of 1400 Cal/day 24% of cal from fat 19% of cal from protein 56% of cal from carbohydrates. Eat five times a day Burn an average of 2,800 Cal a week through exercise 400 Cal/day or 60 min of walking at 15 min/mile

10 Isn t Obesity Simple? Genetics Diet Energy In +/- +/- Exercise Energy Out Energy Regulation is Complex! Sharma AM 2007

11 Central Control of Energy Metabolism

12 Long-Acting Adiposity Signals and Short- Acting Meal-Related Signals that Contribute to Energy Balance Marx J: Science 2003;299:846

13 Adipose Tissue Adipokines Sharma AM & Staels B, JCEM 2007

14 Adaptations To Weight Loss Hormonal changes (e.g. decrease in leptin, increase in ghrelin, etc.) Increase in appetite Decrease in metabolic rate Decrease in activity thermogenesis

15 Biggest Losers Fight a Slower Metabolism New York Times 2016

16

17 Persistence of Hunger and Desire to Eat After Weight Loss Sumithran P, et al. NEJM 27;365:

18 Persistence Ghrelin, Peptide YY, Amylin, and Cholecystokinin (CCK) After Weight Loss Sumithran P, et al. NEJM 27;365:

19 Astrogliosis

20 Morphological Microglial Reactivity in Diet-Induced Obesity in Mice (AIF-1-ir) Stefanie Kälin et al., Nature Reviews Endocrinology 2015 Chow-fed High-fat diet

21 Horvath TL, et al. PNAS 2010;107:14875

22 Diet-Induced Hypothalamic Reactive Gliosis and Obesity in Obesity-Prone Rats Horvath TL, et al. PNAS 2010;107:14875

23 These data suggest that consumption of an HFD has a major impact on the cytoarchitecture of the arcuate nucleus in vulnerable subjects, with changes that might be irreversible due to reactive gliosis. Horvath TL, et al. PNAS 2010;107:14875

24 Hypothalamic Innate Immune Reaction in Obesity Stefanie Kälin et al., Nature Reviews Endocrinology 2015

25 Stunkard: Twin Studies Monozygous Share genes and environment

26 Stunkard: Twin Studies Monozygous Share genes and environment Heterozygous Share environment

27 Gene Map of Common Obesity El-Sayed Moustafa et al. Nature Reviews Endocrinology, 2013

28 Epigenetics nihroadmap.nih.gov

29 J Clin Endocrinol Metab. 2009;94: mothers with bariatric surgery; 54 children before and 57 after surgery yrs old Children born after surgery: 3-fold lower prevalence of severe obesity (11 vs. 35%) greater insulin sensitivity improved lipid profile lower C-reactive protein

30 Increased Melanocortin Expression in Fetal Offspring of Nonhuman Primates Fed a High-Fat Diet Grayson BE, et al. Endocrinology 2010;151:1622 Maternal Control Diet Maternal High Fat Diet

31

32 Phases of Obesity Treatment Phase I (Weight Loss) Phase II (Weight-Loss Maintenance) Weight When you stop treatment, the disease comes back! 3-6 months Indefinitely

33 Typical Treatment Success Behaviour Modification (BM) ~ 3-5% Years

34 Typical Treatment Success Behaviour Modification (BM) ~ 3-5% Years BM+Surgery ~ 20-30%

35 Typical Treatment Success Behaviour Modification (BM) ~ 3-5% Treatment Gap Years BM+Surgery ~ 20-30%

36 Typical Treatment Success Behaviour Modification (BM) ~ 3-5% Medication Years BM+Surgery ~ 20-30%

37 Pharmacological Targets in Obesity Bray et al. Lancet 2016

38

39 A Word On Burning Calories! Image: Canadian Obesity Network

40 Jean-Philippe Chaput & Arya M. Sharma

41 Non-Caloric Benefits of Regular Exercise Cardiorespiratory fitness Insulin Sensitivity Ectopic Fat Daily Routine Self-Esteem Mood Stress Anxiety ADHD Sleep Energy Improved Weight Management & Better Health! Chaput JP & Sharma AM BJN, 2011

42 Key Points Once established obesity becomes a chronic, often progressive disease Complex neuro-endocrine factors defend against weight loss and promote weight regain Recognising obesity as a disease can reduce the bias and stigma of obesity improve education of health professionals in obesity foster investments into obesity prevention and research improve access to obesity treatments

43

44