Week 4 - Obesity and Diabetes - Student Notes PDF

HLSC 4805 NON-COMMUNICABLE DISEASES Week 4 Obesity Diabetes Krystie Robinson-Vincent RN, PhD Obesity  Major Topics Global Pandemic of Obesity Body Mass Index (BMI) Global Burden of Adult Obesity Gender Di...

HLSC 4805 NON-COMMUNICABLE DISEASES Week 4 Obesity Diabetes Krystie Robinson-Vincent RN, PhD Obesity  Major Topics Global Pandemic of Obesity Body Mass Index (BMI) Global Burden of Adult Obesity Gender Differences in Obesity Trends in Obesity Rates Health Consequences of Obesity Mechanisms of Pathogenesis Profile of Adipokines Risk Factors of Obesity Genetics of Obesity Environmental Factors and Obesity  Outline Childhood Obesity Primary Prevention of Obesity Weight Reduction Programs Liposuction Bariatric Therapy  Obesity Pandemic Upward trends in number of overweight and obese adults; pandemic is continuing Obesity increases risk for developing multiple disease conditions: – Diabetes – Cardiovascular disease – Several types of cancers – Musculoskeletal disorders – Gastrointestinal disorders – Respiratory disorders – Reproductive disorders – Poor mental health Obesity Pandemic Most significant public health threats of 21st century Fueled by excess calories and physical inactivity Rise in prevalence of childhood and adolescent overweight and obesity  Earlier onset of obesity- related diseases  Body Mass Index Obesity - excessive body fat; health is negatively affected Body Mass Index (BMI) - BMI=kg/(m2); measuring/classifying levels of adiposity and obesity- related chronic disease risk among adults Childhood obesity measured using percentile cut points based on standardized growth charts  Limitations of Body Mass Index (BMI) Limitations: – Does not really measure body fat – People with increased muscle mass misclassified as overweight/obese – Fat mass underestimated for those who have lost lean mass due to infirmity, sedentary lifestyle, or increasing age – Cut points for being overweight derived from studies of Caucasians – Cut points inaccurate for some ethnic groups Global Burden of Adult Obesity Worldwide prevalence of overweight and obesity has doubled since 1980; 1/3 of world population classified as overweight or obese Number of obese adults in world population more than doubled during 2000-2015; 300 million  700 million  1 billion (2025); 2.2 billion overweight Prevalence of obesity is higher in women (11.2%) than men (7.7%)  Gender Differences in Obesity Prevalence of obesity in women exceeds that in men by 5-10% Attributed to evolutionary pressures that predispose women to store excess fat for reproduction and lactation Differences in distribution of body fat  differences in sex hormones Women, abdominal/visceral adiposity increases with loss of ovarian estrogens; Men, gradual decline in circulating androgens predisposes to accumulation of abdominal fat  Prevalence of Adult Obesity USA US - prevalence of obesity has doubled 13.3% of adult population was classified as obese (1960) Prevalence of obesity exceeded 30% in most states for men and women of most age groups (2008) Prevalence of Adult Obesity Canada Canada - prevalence of obesity increased significantly between 2005 and 2017/18; 22.2% to 27.2% Increases across both sexes, all age groups and all Canadian provinces and territories  Prevalence of Adult Obesity Canada Prevalence of obesity was higher among males than females (28.9% v. 25.4% (2017/2018) Prevalence among adults 40- 69) exceeded 30% Newfoundland and Labrador had highest prevalence (39.4%) British Columbia had lowest (22.8%) prevalence of obesity Quebec and Alberta exhibited largest relative increases in obesity Health Consequences of Obesity Obesity  Obesity and Total Mortality Strongly associated with increased 7% to morbidity, mortality, disability 41% 44% and impaired QOL from from forms diabete Overweight and obesity of s responsible for 2.8 million cancer deaths/year; 5/10 leading cause of 23% from death ischemic Major contributor to morbidity heart disease and mortality in Canada; contributing to 20% premature deaths  Obesity and Type 2 Diabetes Obesity strongest modifiable predictor of T2D US - 70% of cases attributable to overweight and obesity Canada - 61% to 74% of T2D cases attributable to overweight and obesity Increase in obesity prevalence  increase in T2D prevalence Prevalence in pediatric populations accompanied by increase in T2D in children and adolescents Results in β cell mass and insulin secretion which eventually fails  normal glucose tolerance  impaired glucose tolerance  T2D Obesity and CVD Obesity is a major risk factor for development of cardiovascular diseases (CVD) Obese (BMI > 30) 81% more likely to develop coronary heart disease compared to normal weight Obesity and severe obesity (BMI≥35 kg/m2) strongly related with higher risk of incident CVD and CVD mortality  Obesity and CVD Obesity is associated with risks for coronary heart disease, atrial fibrillation, and heart failure Intra-abdominal obesity a cardiovascular risk state; contributes to or directly causes most other modifiable risk factors Exacerbate CVD through systemic inflammation, hypercoagulability, and activation of sympathetic and renin-angiotensin systems Risk of CVD increases with BMI, even in absence of metabolic abnormalities  Obesity and Cancer Significant risk factor for many cancers; association does not affect all subgroups equally Colon cancer - higher in obese men than obese women Breast Cancer - obesity increases risk in postmenopausal women but not premenopausal women; adipose tissue is primary source of estrogens after menopause  Obesity and GERD Abdominal adiposity is of particular importance in pathogenesis of GERD and its progression Obesity associated with many factors leading to increased esophageal acid exposure: – increased intra-abdominal pressures – impaired gastric emptying – decreased lower esophageal sphincter pressure – increased frequency of transient sphincter relaxation Increased BMI and visceral fat associated with 2-3 fold increased risk of developing reflux symptoms and esophageal lesions Barrett’ Esopha Erosive s geal Complications Esophagitis Esopha Carcino  Other Health Consequences of Obesity Health Consequence Description Sleep Apnea Major risk factor for the development of obstructive sleep apnea Prominent among men with abdominal obesity Improve/resolve with weight loss Osteoarthritis Strong association between obesity and osteoarthritis of major weight-bearing joints Quality of Life Associated with decreased overall quality of life Mechanisms of Pathogenesis Obesity and excess weight increase mechanical stress and strain on multiple systems Excess weight  compression of blood vessels and body organs  mechanical resistance and distortion of normal function Adipose tissue - active endocrine organ secretes adipokines; critical role in whole body metabolic regulation and cellular energy homeostasis Mechanisms of Pathogenesis Risk Factors of Obesity Modifiable Risk Factors of Obesity Diet Exercise Sleep Stress Take in more Sedentary 7-9 hours of Chronic stress calories than lifestyle  risk uninterrupted  activate you use. of obesity sleep/night biological Body stores Remain Getting too pathways fat sedentary for little sleep  (stress-related Limiting too long  metabolic factors + processed weight gain + changes  stress foods obesity weight gain hormones)  Over Obesity rates body hold consumption higher in onto extra of added sugar areas where weight is a risk factor adults report Saturated fats no physical higher risk of activity CVD; calorie dense  obesity  Genetics of Obesity Importance of genetics related to increase in prevalence of obesity Family members share similar environments and behaviors (diet and exercise) Significant genetic impact on measures of body mass and obesity Three genetic patterns:  Environmental Factors Increase risk of developing obesity by influencing energy intake and energy expenditure Increased sedentary behaviors linked to childhood adiposity Two environmental factors: – Food marketing strategies (especially to children) and – 24-hour availability of convenience/processed food  Burden of Childhood Obesity Globally, number of overweight children < 5 years increased from 20 million (2005) to 43 million (2010) Obesity rates higher in developed countries; developing countries have far more children that are obese 35 million overweight/obese preschoolers in developing countries; 8 million in developed countries Changes in diets and lifestyles  weight gain and obesity  health threats Burden of Childhood Obesity  Childhood Obesity USA Prevalence did not exceed 15% in any state; in 10 states prevalence < 10% (1990) Only 1 state had prevalence < 20%; in 32 states, ¼ of all children classified as obese (2008) Ethnic Groups - more common among African Americans, Hispanics, and American Indians compared to Caucasians Socioeconomic Status - obesity highest in low-income children Childhood Obesity USA  Childhood Obesity Canada ¼ or 23% of children 2- 17 were overweight or obese (1978)  35% (2004)  1/3 (30- 33%) between 5-17 classified as overweight or obese Boys more likely than girls to be obese; highest between 12-17 years (16.2% vs 9.3%)  Perinatal/Postnatal Factors and Obesity Maternal Obesity Pharmacolo gical Diabetes Maternal Stressors Diet and health Immunologi Infant Adiposity Feeding cal Malnutrition Rebound Patterns Stressors Psychologica l Stressors Health Consequences of Childhood Obesity Prevention of Obesity Therapy of Obesity Liposuction Liposuction – surgical removal of subcutaneous fat with aspiration cannulas assisted by suction; primarily for cosmetic purposes Not considered weight-loss method or alternative Lose more weight through diet/exercise Studies needed to determine both short term and long term impact of high volume liposuction  Therapy of Obesity Bariatric Surgery Bariatric Surgery - gastric bypass or metabolic surgery; elective surgical weight loss procedure reduces gastric reservoir/limits food intake Only proven treatment for severe obesity Types: – Roux-en-Y Gastric Bypass (RYGB) – Gastric bypass - constructs a small pouch; bypassing part of stomach and duodenum – Sleeve Gastrectomy (SG) – Gastric sleeve; remove large portion of stomach without bypassing intestines – Laparoscopic Adjustable Gastric Band (LAGB) – Gastric band; laparascopic surgery where an inflatable band is placed around the stomach to create pouch  Conclusions Number of obese adults more than doubled during 2000-2015, from 300 million to 700 million Consequence of increased urbanization and environmental changes; decreased physical activity, increased sedentary behavior, ready access to high fat, high sugar, energy dense, cheap food/drink Risk factors include genetic susceptibility, female gender, aging, ethnicity, perinatal factors (maternal obesity), menopause, psychological factors (stress, depression) and physiological factors (adiposity rebound and fat cell dynamics)  Conclusions Obesity significant risk factor for type 2 diabetes, cardiovascular diseases (such as coronary heart disease, myocardial infarction, and stroke), gastroesophageal reflux disease (GERD), obstructive sleep apnea, asthma, gall bladder and fatty liver disease, depression, urinary incontinence, gout, polycystic ovarian syndrome, and osteoarthritis  Conclusions Obesity has become one of the leading causes of premature death and disability in the world; 2.8 million deaths annually, ranking fifth among the top ten leading causes of death worldwide Visceral (abdominal) fat is more metabolically active than subcutaneous (peripheral) fat; responsible for increasing risk of developing obesity-related diseases  Conclusions Obesity can be classified into types: hypertrophic obesity (increased fat cell size) and hyperplastic obesity (increased fat cell number) Preventive and therapeutic strategies should be designed to counteract both types Prevalence of obesity in children has risen dramatically Comprehensive/sustainable prevention programs should be established to encourage healthy, nutritious eating habits and physically active lifestyles in order to avoid development of obesity and obesity-related diseases in future generations