Why Do We Treat Obesity? Epidemiology

Epidemiology of Obesity U.S. Epidemic

More than Two Thirds of US Adults Are Overweight or Obese NHANES Data US Adults Age ≥20 Years (Crude Estimate) 1.7-fold increase in obesity since 1962 BMI ≥30 BMI 25-29 BMI = body mass index (in kg/m2); NHANES = National Health and Nutrition Examination Survey (x-axis lists last year of each survey). Flegal KM, et al. Int J Obes Relat Metab Disord. 1998;22:39-47; Flegal KM, et al. JAMA. 2002;288:1723-1727; Flegal KM, et al. JAMA. 2010;303:235-241; Flegal KM, et al. JAMA. 2012;307:491-497. Ogden CL, et al. JAMA. 2014;311:806-814.

Obesity Rates Are Increasing Across the United States BFRSS Data Adults with BMI ≥30 kg/m2 No data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30% (2010) 30%-34% (2011-2013) ≥35% 1990 2011* 2000 2012* From the 1980s through 2010, the CDC used the post-stratification method to adjust respondent data to known proportions of age, race and ethnicity, gender, and geographic region to ensure the sample was representative of the population and also adjust for nonresponse bias. Beginning with the 2011 dataset, the CDC has used a methodology called raking, which allows incorporation of a greater number of demographic variables than were possible with post-stratification. These include1: Telephone source (land line or mobile phone) Detailed race and ethnicity information Regions within states Education level Marital status Age group by gender Gender by race and ethnicity Age group by race and ethnicity Homeowner status These methodological changes have facilitated collection of more data from younger persons and those of nonwhite race or ethnicity or lower socioeconomic status. As a result, datasets collected after 2010 are likely to show indications of somewhat higher occurrences of risk behaviors common to younger adults and to certain racial or ethnic minority groups, including obesity. Shifts in prevalence from 2010 to 2011 and later probably reflect the new methods of measuring risk factors, rather than true trends in risk-factor prevalence. For this reason, comparisons between data collected before and after 2010 are not recommended.2 Centers for Disease Control and Prevention. Behavioral Risk Factor Surveillance System Improving Survey Methodology Fact Sheet. Available at: http://www.cdc.gov/surveillancepractice/documents/DBS_BRFSS%20Improvements_12_232372_M_REM_5_25_2012.pdf Centers for Disease Control and Prevention. Frequently Asked Questions About Changes to the Behavioral Risk Factor Surveillance System. Available at: http://www.cdc.gov/surveillancepractice/reports/brfss/brfss_faqs.html 2010 2013* *BFRSS methodology changed in 2011 and data from 2010 and earlier cannot be compared to data from 2011 onward. BRFSS = Behavioral Risk Factor Surveillance System; BMI = body mass index. CDC. Adult obesity facts. Available at: http://www.cdc.gov/obesity/data/trends.html.

Prevalence of Obesity Varies With Race, Ethnicity, and Sex NHANES Data US Adults Age ≥20 Years With BMI ≥30 Population (%) NHANES surveys conducted up to 2008 reported prevalence among Latino populations for Mexican Americans only. The 2009-2010 survey (published in 2012) reported prevalence estimates for the “Hispanic” (term used in reference) population, including Mexican Americans, and for Mexican Americans separately. The 2011-2012 survey (published in 2014) reported the prevalence for the total Hispanic population, without separating Mexican Americans or other nationalities. *Estimates based on Mexican Americans only for 1980-2008. BMI = body mass index (in kg/m2); NHANES = National Health and Nutrition Examination Survey (x-axis lists last year of each survey). Flegal KM, et al. Int J Obes Relat Metab Disord. 1998;22:39-47; Flegal KM, et al. JAMA. 2002 ;288:1723-1727; Flegal KM, et al. JAMA. 2010;303:235-241; Flegal KM, et al. JAMA. 2012;307:491-497. Ogden CL, et al. JAMA. 2014;311:806-814.

Epidemiology of Obesity Worldwide Trends

Worldwide Prevalence of Obesity 2015 Women, Age ≥18 Years <10.0% 10.0%-19.9% 20.0%-29.9% ≥30% Data not available Not applicable BMI ≥30 kg/m2 Men, Age ≥18 Years WHO. Global Health Observatory Map Gallery. Available at: http://gamapserver.who.int/mapLibrary/app/searchResults.aspx.

Obesity Increase Is Associated with Rising Rates of Diabetes Worldwide Current estimated prevalence: 415 million worldwide By 2040, 642 million people worldwide are expected to have diabetes IDF. Diabetes Atlas Update 2015. Available at: http://www.idf.org/sites/default/files/Atlas7e-poster.pdf.

Strong Association Between Weight Gain and Diabetes: Rural India Obesity* Diabetes 750% increase 191% increase *BMI ≥25 kg/m2. BMI = body mass index. Ramachandran A, et al. Diabetologia. 2004;47:860-865.

The Increase in Diabetes Parallels the Increase in Obesity in the United States Population (%) *BMI ≥30 kg/m2. BMI = body mass index. CDC. National diabetes statistics report, 2014. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, 2014. Mokdad AH, et al. JAMA. 1999;282:1519-1522; Mokdad AH, et al. Diabetes Care. 2000;23:1278-1283; Ogden CL, et al. JAMA. 2014;311:806-814.

Impact on Clinical Outcomes Epidemiology of Obesity Impact on Clinical Outcomes

The Risk of Chronic Conditions Increases With BMI Women Men Type 2 diabetes Hypertension Cholelithiasis Coronary heart disease BMI (kg/m2) <21 22 23 24 25 26 27 28 29 30 6 5 3 2 1 4 Relative Risk BMI (kg/m2) 6 5 3 2 1 4 <21 22 23 24 25 26 27 28 29 30 Increased abdominal adiposity is highly correlated with insulin resistance and type 2 diabetes BMI = body mass index. Willett WC, et al. N Engl J Med. 1999;341:427-434. Carey VJ, et al. Am J Epidemiol. 1997;145:614-619.

Prevalence of Weight-Related Comorbidities in the US NHANES 2007-2010 US 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 cholesterol-lowering drug FPG ≥126 mg/dL, A1C ≥6.5%, or DM diagnosis Normal weight = BMI 18 to <25 kg/m2; overweight = BMI 25 to <30 kg/m2; obese = BMI ≥30 kg/m2 BMI = body mass index; DM = diabetes mellitus; DBP = diastolic blood pressure; HDL-C = high density lipoprotein cholesterol; HT = hypertension; SBP = systolic blood pressure. Saydah S, et al. Obesity (Silver Spring). 2014;22:1888-1895.

Mortality Increases with BMI Cancer Prevention Study II (N=1,046,154) 32.0-34.9 Overweight Obese Normal <18.5 18.5-20.4 20.4-21.9 22.0-23.4 23.5-24.9 25.0-26.4 26.5-27.9 28.0-29.9 30.0-31.9 35.0-39.9 >40.0 0.6 1.0 1.4 1.8 2.2 2.6 3.0 Men Women CVD death risk significantly increased Relative risk of death* Cardiovascular disease Cancer All other causes *Cox proportional hazards model adjusted for age at enrollment, education, physical activity, alcohol use, marital status, aspirin use, fat consumption, vegetable consumption, and use estrogen replacement therapy in women. Calle EE, et al. New Engl J Med. 1999;341:1097-1105.

All-Cause Mortality Increases with BMI National Institutes of Health AARP Cohort Study, 1996-2009 (N=109,947 Never-Smokers) P<0.0005 for linear trend Multivariate hazard ratio* (Referent) Body mass index (kg/m2) *Regression analyses adjusted for age, race/ethnicity, education, leisure-time physical activity, and alcohol consumption. Adams KF, et al. Am J Epidemiol. 2014;179:135-144.

Earlier Weight Gain Increases Total Mortality Risk National Institutes of Health AARP Cohort Study, 1996-2009 (N=109,947 Never-Smokers) Multivariate hazard ratio* (Age 50-71) Age at which BMI ≥25 kg/m2 *Regression analyses adjusted for age, race/ethnicity, education, leisure-time physical activity, and alcohol consumption. Adams KF, et al. Am J Epidemiol. 2014;179:135-144.

Racial Differences in BMI-Mortality Association National Health Interview Survey, 1997-2006 All-Cause Mortality Rates Among Individuals Who Have Never Smoked Deaths per 1000 person-years Body mass index (kg/m2) Age-standardized all-cause mortality rates for persons aged 35-75 years without a history of heart disease or cancer at baseline. Jackson CL, et al. Obesity (Silver Spring). 2014;22:842-851.

Epidemiology of Obesity Economic Impact

The Effect of Weight on Healthcare Costs U.S. Adults (N=23,689) Medical expenditures Confidence interval Population distribution Cawley J, Meyerhoefer C. J Health Econ. 2012;31:219-230.

Obesity-Related Illness Accounts for One-Fifth of U. S Obesity-Related Illness Accounts for One-Fifth of U.S. Healthcare Costs Obesity Costs1 U.S. Adults Age ≥18 Years Diabetes Costs2 U.S. Residents, All Ages Total $923.2 billion Total $1,300 billion Obesity $190.2 billion 20.6% of total costs Diabetes $176 billion 13.5% of total costs 1. Cawley J, Meyerhoefer C. J Health Econ. 2012;31:219-230. 2. ADA. Diabetes Care. 2013;36:1033-1046.

Annual Increase in Medicare Expenditures Medicare Spending Is Rising Significantly Faster in the Overweight Population Annual Increase in Medicare Expenditures 1997-2006 P=0.001 P=0.01 After adjustment for obesity-related chronic conditions, interactions were no longer significant Alley D, et al. Arch Intern Med. 2012;172:277-278.

Obesity Significantly Increases Medicare Expenditures Mean Expenditures in 2003 Individuals >65 Years of Age ** ** ** ** *Includes dental and other costs not shown. **P≤0.001 vs normal weight. BMI = body mass index in kg/m2. Wilkins TL, et al. Obesity (Silver Spring). 2012;20:1240-1248.

Weight Loss Reduces Lifetime Healthcare Costs Projected Lifetime Healthcare Expenditures Obese Individuals <45 Years of Age + $1700 + $930 Cost offsets + $23 - $357 - $4080 - $8100 5% Weight Loss for 2 Years Total Benefit $334 Permanent 5% Weight Loss Total Benefit $3150 Permanent 10% Weight Loss Total Benefit $6400 Dall TM, et al. Am J Prev Med. 2011;40:338-344.

Summary Obesity is increasing globally Obesity is costly Rates of obesity have risen dramatically in the United States over the past 4 decades The increase in obesity is strongly associated with the increase in diabetes in the U.S. and worldwide Obesity is costly