OBESITY OVERVIEW. Natsurang Chongkrairatanakul, MD

Transcription

1 OBESITY OVERVIEW Natsurang Chongkrairatanakul, MD Diplomat of American Board of Obesity Medicine Assistant Professor of Internal Medicine, Endocrinology Diabetes and Nutrition Froedtert & Medical College of Wisconsin Disclosure I have no financial disclosure 1

2 Objectives Definitions of overweight and obesity Incidence and prevalence of obesity in the U.S. Actual percent and rate of growth Demographic, geographic and age distributions Genetic, environmental and cultural risk factors of obesity Obesity related diseases Financial impacts of obesity Definition of Obesity CDC - Weight that is higher than what is considered as a healthy weight for a given height WHO - An abnormal or excessive fat accumulation in the body that may impair health 2

3 Body Mass index (BMI) OBESITY CLASS I OBESITY CLASS II >40 OBESITY CLASS III Adapt from Body Mass index (BMI) BMI is a convenient screening tool to measure body fat content The accuracy of BMI is higher in persons with high BMI but even if 2 people have the same BMI, their levels of body fat content may differ Limitations: Measure both fat mass (FM) and fat free mass (FFM) Distribution of fat e.g. android vs gynoid Ethnic differentiation e.g. at any given BMI, there is 5% higher FM in Asian population At the same BMI, there is more body fat content in: Women > men Asians > Whites > Blacks Older adults > younger adults Non-athletes > athletes 3

4 Definition of Overweight and Obesity Adults Overweight: BMI 25 Obesity: BMI 30 Children under 5 years of age Overweight: weight-for-height >2 SDs above WHO Child Growth Standards median Obesity: weight-for-height >3 SDs above the WHO Child Growth Standards median Children aged between 5 19 years Overweight: BMI-for-age >1 SD above the WHO Growth Reference median Obesity: BMI-for-age >2 SD above the WHO Growth Reference median Prevalence of Obesity Among U.S. Adults Derived from NHANES data ( 4

5 Obesity Prevalence Among U.S. Adults and Youth *Not significant Prevalence of Obesity Among U.S. Adults, 2016 Higher prevalence found in the South and the Midwest Lower prevalence observed in the Northeast and the West 5

6 Prevalence of Obesity Among Non-Hispanic White Adults, Prevalence of Obesity Among Non-Hispanic Black Adults,

7 Prevalence of Obesity Among Hispanic Adults, Prevalence of Obesity Among U.S. Adults, by Age and Sex: Obesity rate is higher among middle age adults for both men and women (40.2%), followed by older adults age 60 and over (37.0%) 7

8 Prevalence of Obesity Among U.S. Adults, by Sex and Race: Non-Hispanic blacks have the highest age-adjusted rates of obesity (48.1%) followed by Hispanics (42.5%), non-hispanic whites (34.5%), and non- Hispanic Asians (11.7%) When categorized by sex, Hispanic men have the highest rates of obesity (39%) while non- Hispanic black women have the highest rate of obesity (56.9%) Obesity Affects Some Groups More Than Others Non-Hispanic blacks have the highest rates of obesity followed by Hispanics, non- Hispanic whites, and non-hispanic Asians Obesity is higher among middle age adults years and older adults over 60 Among non-hispanic black and Mexican-American men, those with higher incomes are more likely to have obesity Higher income women are less likely to have obesity than low-income women There is no significant relationship between obesity and education among men Among women, there is a trend those with college degrees are less likely to have obesity 8

9 Contributors to the Obesity Epidemic Drug induced weight gain Cultural beliefs on food Food marketing Behaviors, dietary trend and habits Increased obesity prevalence Epigenetics Endocrine disruptions Lack of sleep Reduced physical activity Appetite dysregulation/ Energy homeostasis disruption Genetic of Obesity Obesity is genetically influenced condition, but it is not a simple Mendalian trait As of 2015, there are 97 associated genetic loci from an analysis of >300,000 of individuals but only accounted for 2.7% of the BMI variation seen in population Ramachandrappa S et al. Genetic approaches to understanding human obesity. J Clin Invest 2011 June 1; 121(6)

10 Drug-induced Obesity Diabetes medications Insulin TZDs Sulfonylurea (up to 5 Kg first 3-12 months) Anti-psychotics and mood stabilizers TCAs (0.4-4 Kg/month) SSRIs Lithium (most patients gain >10 Kg) Olanzapine is the worst Anti-seizure medications (up to 20 Kg) Gabapentin Pregabalin Steroid hormones Antihistamine (except Loratadine) Beta-blockers HAART esp protease inhibitors Sports & Leisure Lack of outdoor areas Widely available indoor activities Unsafe streets Lack of public transportation Few cycle routes Education & Information Lack of school lessons Cultural beliefs Obesogenic Environment Sociocultural Preference for foods high in fat and/or carbohydrates Large portion size (value meal) Society acceptance of obesity Readily available snacks & soft drinks Sponsorship Eating out Advertising Family Genetic predisposition to obesity Excess weight in parents & family members Shorter period of breast-feeding Lack of knowledge Financial Shopping & cooking skills Work & life circumstances Sedentary occupations Heavy time commitments to work, social and family obligations Sleep deprivation Working night shift 10

11 Possible Cognitive Behavioral Mechanisms Underlying Development of Obesity Normal Conditioned memory Reward signals Inhibitory control Drive to eat Abnormal Conditioned memory* Reward signals Inhibitory control Drive to eat *Chronic exposure to obesity-promoting behaviors (e.g, alcohol use, sleep deprivation, TV) Chapman CD, et al. Am J Clin Nutr. 2012;96: Effects of Alcohol, Sleep Deprivation, and TV Watching on Food Intake Effect size (95% CI) P value No. studies / subjects Alcohol 1.03 (0.66, 1.4) < / 278 Sleep deprivation 0.49 (0.11, 0.88) / 78 TV watching 0.20 (0.04, 0.37) / 363 Food intake higher Chapman CD, et al. Am J Clin Nutr. 2012;96:

12 Obesity is a Disease Many professional societies and organizations have accepted obesity as a disease and have adopted treatment guidelines for clinicians American Associated of Clinical Endocrinologists (AACE) recognize obesity is a primary disease and the full force of medical knowledge should be brought to bear on the prevention and treatment of obesity Impairment of Normal Function Physical impairments Altered physiologic function (inflammation, insulin resistance, dyslipidemia, etc) Altered regulation of satiety in the hypothalamus Characteristic Signs or Symptoms Increased body fat mass Joint pain Impaired mobility Low self-esteem Sleep apnea Altered metabolism Complications Cardiovascular disease Type 2 diabetes Metabolic syndrome Cancer AMA = American Medical Association. Mechanick JI, et al. Endocr Pract. 2012;18:

13 The Risk of Chronic Medical Conditions Increases With BMI Women Men Type 2 diabetes Hypertension Gall stones Coronary heart disease Relative Risk < BMI (kg/m 2 ) < BMI (kg/m 2 ) Adapt from Willett WC, et al. N Engl J Med. 1999;341: Carey VJ, et al. Am J Epidemiol. 1997;145: Prevalence of Weight-Related Comorbidities NHANES U.S. Adults Age 18 Years (N=12,175) SBP 140 mmhg, DBP 90 mmhg, or using anti-ht drug Non-HDL-C 160 mg/dl or using cholesterollowering drug FPG 126 mg/dl, A1C 6.5%, or DM diagnosis Saydah S, et al. Obesity (Silver Spring). 2014;22:

14 Age-Adjusted Prevalence of Obesity and Diagnosed Diabetes Among U.S. Adults Source: CDC s Division of Diabetes Translation. National Diabetes Surveillance System, Obesity and Cancer Obesity is associated with type specific cancers For each 5 kg/m2 increase in BMI, there was a linear association with cancers of uterus, gall bladder, kidney, cervix, thyroid and leukemia High BMI was associated with liver, colon, ovarian, and postmenopausal breast cancers Bhaskaran, K et al. Body-mass index and risk of 22 specific cancers: a population-based cohort study of 5 24 million UK adults. Lancet. 2014; 384(9945):

15 Obesity and Cardiovascular Disease Obesity is associated with an increased of 4% per 1 unit of BMI of new onset atrial fibrillation (? Due to left atrial dilation) Obesity causes LVH, increases risk for CHF and sudden death syndrome Weight gain is directly related to these cardiovascular risk factors: Dyslipidemia Hypertension Elevated insulin level Elevated fibrinogen Bray G. Handbook of Obesity Wang, TJ et al. Obesity and the risk of new-onset atrial fibrillation. JAMA. 2004;292(20): Obesity and Stroke For every increase in BMI by 1 unit, there is an increase in Hemorrhagic stroke by 6% Ischemic stroke by 4% Steelman, GM et al. Obesity: Evaluation and Treatment Essentials

16 Obesity and Liver Disease Liver abnormalities associated with obesity includes hepatomegaly, elevated LFTs, and abnormal liver histology (ranges from hepatic steatosis to non-alcoholic steatohepatitis) Non-alcoholic steatohepatitis (NASH) is found in 15-30% of normal population, up to 70% in DM type % prevalence in those with BMI >30 90% of patients with BMI >40 will have hepatic steatosis Weight loss (esp rapid weight loss) may increase transaminases transiently Tarantino, G. et al. Non-alcoholic fatty liver disease: Further expression of the metabolic syndrome. J Gastroenterol Hepatol. 2007;22(3): Obesity and Gallbladder Disease Increased incidence as BMI increases Increased body fat increased cholesterol production increased cholesterol turnover increased risk of gallstones For every 1 unit of increased BMI, there is a 7% higher risk of gallstone formation Recycling of weight increases RR for cholecystectomy ( RR) Stampfer, MJ et al. Risk of symptomatic gallstones in women with severe obesity. Am J Clin Nutr Mar;55(3): Bray GA. Medical consequences of obesity. J Clin Endocrinol Metab. 2004;89(6):

17 Obesity and Sleep Apnea Sleep apnea abnormal breathing during sleep that causes recurrent arousals, sleep fragmentation, and nocturnal hypoxemia Can result in daytime sleepiness, impaired cognitive function, and organ malfunction such as pulmonary HTN, stroke, right sides heart failure, and cardiac arrhythmias Occurs >30% in patients with BMI >30 and 50-98% in patients with BMI >40 An increase in BMI by 1 unit leads to a 30% increase in the RR of developing abnormal sleep-disordered breathing Risk factors include neck circumference >17 inches in men and >16 inches in women, older age and male sex (male-to-female ratio is 2:1) Weaker associations include menopause, family history, smoking, and nighttime nasal congestion Steelman, GM. Obesity: Evaluation and Treatment Essentials Hensley et al. Sleep apnea. Am Fam Physician ;81(2): Epworth Sleepiness Score (ESS) A subjective assessment of daytime sleepiness Patients are asked to assign a numerical value to each of the following situations to indicate the likelihood that they might fall asleep: Sitting and reading - Lying down to rest in the afternoon Watching television - Sitting while conversing Sitting in a public place or meeting - Sitting after lunch (without alcohol) As a passenger in a car for an hour - As a passenger in a car stopped in traffic for a few minutes Score: 0 = would never sleep, 1 = a slight chance of sleeping, 2 = a moderate chance of sleeping, 3 = a high chance of sleeping A total score 10 is considered abnormal and a score 16 indicates pathological daytime sleepiness 17

18 Sleep & Obesity Lower sleep level is associated with a higher BMI Adults with 7.7 hours of sleep had the lowest BMI Sleep reduction is associated with decreased leptin, increased ghrelin and increased hunger Shorter or longer sleep duration is associated with greater mortality Highest mortality was <4.5 hours and >10 hours Mild OSA is associated with increase A1c by 1.49%, compared to 1.93% and 3.69% in moderate and severe OSA Healthcare night shift work increases obesity Aging and Obesity BMI gradually increases during adult life with peak at years Fat free mass (FFM) starts to decrease at age Aging decreases all aspect of total energy expenditure (TEE) Decreased resting metabolic rate (RMR) by 2-3% per decade after age 20 Decreased thermic effect of food Decreased physical activity Fat mass Muscle mass Stenholm S, et al. Curr Opin Clin Nutr Metab Care. 2008;11:

19 Weight Loss Improves Obesity Related Medical Conditions 10% weight loss will beneficially improve the following conditions: Osteoarthritis Rheumatoid arthritis Low back pain Carpal Tunnel Syndrome Gout Cancers of breast, esophagus, stomach, colon CAD Dyslipidemia HTN Chronic venous insufficiency Deep vein thrombosis Stroke Chronic kidney disease Type 2 diabetes Impaired respiratory function Obstructive sleep apnea Infection following wound healing Infertility Neural tube defects Liver disease Pancreatitis Gall bladder disease Surgical complications Urinary stress incontinence Weight Loss for Primary Prevention: LOOK AHEAD Study The average follow-up was 2.8 years The incidence of DM was 11, 7.8, and 4.8 cases per 100 personyears in the placebo, metformin, and lifestyle groups, respectively The lifestyle intervention reduced the incidence of DM by 58% and metformin by 31%, as compared with placebo Knowler, WC et al. Reduction in the incidence of type 2 DM with lifestyle intervention or metformin. N Engl J Med 2002; 346(6):

20 Weight Loss for Primary Prevention: HbA1c and Fasting Glucose Wing, RR et al. Benefits of Modest Weight Loss in Improving Cardiovascular Risk Factors in Overweight and Obese Individuals With Type 2 Diabetes. Diabetes Care 2011;34(7): Weight Loss for Primary Prevention: Blood Pressure and Triglyceride Wing, RR et al. Benefits of Modest Weight Loss in Improving Cardiovascular Risk Factors in Overweight and Obese Individuals With Type 2 Diabetes. Diabetes Care 2011;34(7):

21 Weight Loss for Primary Prevention: HDL and LDL Cholesterol Wing, RR et al. Benefits of Modest Weight Loss in Improving Cardiovascular Risk Factors in Overweight and Obese Individuals With Type 2 Diabetes. Diabetes Care 2011;34(7): Obesity is Common, Serious and Costly The estimated annual medical cost of obesity in the U.S. was $147 billion in 2008 and is now estimated at $270 billion/ year If we do not make changes, it could be at $ billion/year by 2030 The medical costs for people who have obesity were $1,426 higher than those of normal weight 21

22 Source: Reuters, KEAS, Centers for Disease Control and Prevention Take Home Points Obesity is a complex, multifactorial and relapsing disease with multiple signals influencing the brain and appetite that requires lifelong treatment Obesity is common, serious and costly Prevalence of obesity is significantly increased since 1980 with highest in the South and the Midwest of the U.S. Over 50% of the U.S. population may be affected by obesity by 2030 Obesity affects some groups more than others 22

23 Take Home Points The risk of chronic medical conditions increases with higher BMI e.g. hypertension, DM, dyslipidemia, CAD etc 5-10% weight loss from baseline can positively improve incidence of type 2 diabetes, high blood pressure, lipid profiles, quality of life, and financial burden on the individual and for the country How we approach the complex issues of obesity requires a comprehensive and team-based approach. Having a good understanding of pathophysiology of obesity can help us manage patients appropriately. You do not need to be skinny to be healthy 23