Implications of the Obesity Paradox for Weight Stigma in Healthcare Tamara Horwich, MD, MS Health Sciences Associate Clinical Professor of Medicine / Cardiology Co-Director, UCLA Women’s Cardiovascular Center
What We Learn in Medical School Risk Factors for Cardiovascular Disease • • • • • • • • •
Older Age Male Gender Cigarette Smoking Hypertension High Cholesterol Diabetes Family History of CAD Obesity Physical Inactivity AHA Scientific Position, March 9 2010 (americanheart.org)
What Obesity Can Lead To. . . . • • • • • • •
Diabetes High Blood Pressure Coronary Artery Disease Stroke Cancer Sleep Apnea Osteoarthritis
2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults Endorsed by the American Associa2on of Cardiovascular and Pulmonary Rehabilita2on, American Pharmacists Associa2on, American Society for Nutri2on, American Society for Parenteral and Enteral Nutri2on, American Society for Preven2ve Cardiology, American Society of Hypertension, Associa2on of Black Cardiologists, Na2onal Lipid Associa2on, Preven2ve Cardiovascular Nurses Associa2on, The Endocrine Society, and WomenHeart: The Na2onal Coali2on for Women with Heart Disease © American College of Cardiology Founda2on and American Heart Associa2on, Inc.
Obesity Context • Most primary care physicians (PCPs) are not trained in obesity etiology, pathogenesis, diagnosis and treatment • Culture promotes supplements and dietary approaches that promise quick and easy weight loss • PCPs need authoritative recommendations for managing weight to improve their patient’s health
2013 American Heart Association / American College of Cardiology Recommendation #1
I IIa IIb III
1a. Measure height and weight and calculate BMI at annual visits or more frequently. (BMI = weight in kg/ height in m2)
I IIa IIb III
I IIa IIb III
I IIa IIb III
1b. Use the current cutpoints for overweight (BMI >25.0-29.9 kg/m2) and obesity (BMI ≥30 kg/m2) to identify adults who may be at elevated risk of CVD and the current cutpoints for obesity (BMI ≥30 kg/m2) to identify adults who may be at elevated risk of mortality from all causes. 1c. Advise overweight and obese adults that the greater the BMI, the greater the risk of CVD, type 2 diabetes, and all-cause mortality.
1d. Measure waist circumference at annual visits or more frequently in overweight and obese adults. Advise adults that the greater the waist circumference, the greater the risk of CVD, type 2 diabetes, and all-cause mortality. The cutpoints currently in common use (from either NIH/NHLBI or WHO/IDF) may continue to be used to identify patients who may be at increased risk until further evidence becomes available.
Recommendation 2 I IIa IIb III
Counsel overweight and obese adults with cardiovascular risk factors (high BP, hyperlipidemia, and hyperglycemia), that lifestyle changes that produce even modest, sustained weight loss of 3%–5% produce clinically meaningful health benefits, and greater weight losses produce greater benefits. a.
Sustained weight loss of 3%–5% is likely to result in clinically meaningful reductions in triglycerides, blood glucose, hemoglobin A1c, and the risk of developing type 2 diabetes. b. Greater amounts of weight loss will reduce BP, improve LDL-C and HDL-C, and reduce the need for medications to control BP, blood glucose and lipids as well as further reduce triglycerides and blood glucose.
Recommendation 3a I IIa IIb III
Prescribe a diet to achieve reduced calorie intake for obese or overweight individuals who would benefit from weight loss, as part of a comprehensive lifestyle intervention. Any one of the following methods can be used to reduce food and calorie intake: a.
Prescribe 1,200–1,500 kcal/d for women and 1,500–1,800 kcal/d for men (kilocalorie levels are usually adjusted for the individual’s body weight); b. Prescribe a 500-kcal/d or 750-kcal/d energy deficit; or c. Prescribe one of the evidence-based diets that restricts certain food types (such as high-carbohydrate foods, low-fiber foods, or high-fat foods) in order to create an energy deficit by reduced food intake.
Recommendation 5 I IIa IIb III
5a. Advise adults with a BMI ≥40 kg/m2 or BMI ≥35 kg/m2 with obesity-related comorbid conditions who are motivated to lose weight and who have not responded to behavioral treatment with or without pharmacotherapy with sufficient weight loss to achieve targeted health outcome goals that bariatric surgery may be an appropriate option to improve health and offer referral to an experienced bariatric surgeon for consultation and evaluation.§
Hughes. Nature 2013.
The Unexpected Truth About Body Weight
Survival in UCLA Heart Failure Patients Divided by Body Mass Index (BMI)
Adjusted for: age, sex, cardiac function, comorbidities, severity of disease
. Horwich. Journal of the American College of Cardiology 2001
Body Mass Index and HF: Insight from CHARM Trial (n=7599) BMI<22.5, HR 1.69 BMI 22.5-24.9, 1.46
40
Mortality (%)
Log Rank p value <0.0001
BMI 25-29.9, 1.22
30
BMI≥35, 1.17 BMI 30-34.9, HR 1.0
20 10 0 0
0.5
1
1.5
2
2.5
3
3.5
4
Time (years) Kenchaiah et al. Circulation 2007; 116: 627-636.
Relationship Between BMI and Mortality in Severe Chronic Obstructive Pulmonary Disease (COPD) Severe COPD
Relative Risk
2.5 2 1.5 1 0.5 0 <20
20-24.9
25-29.9
Body Mass Index, kg/m2 Landbo et al. Am J Resp Crit Care Med 1999; 60: 1856-61.
>=30
“Obesity Paradox” in Patients on Maintenance Hemodialysis N=9714 HD patients from the Dialysis Outcomes and Practice Patterns Study (DOPPS)
Deaths/100 pt-yrs
30 25 20 15 10 5 0 <20
20-22.9
23-24.9
25-29.9
>30
BMI, kg/m2 Leavey SF et al. Nephrol Dial Transplant 2001;16:2386-94.
Hudson Street Press, 2014
Potential Explanations for the “Obesity Paradox” in Chronic Disease 1. Obese patients are simply less sick 2. Obesity or increased fat or increased lean mass is protective in terms of altering stress and inflammatory hormones 3. High body mass index (or higher % body fat or higher lean mass) represents greater metabolic reserve in HF (a catabolic state) to protect against the ravages of chronic disease
Obesity Paradox in Hypertension and Coronary Artery Disease
Hazard Ratio
Death, MI, CVA 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0
All Cause Mortality
P<0.001 N = 22,756, INVEST
Thin
Normal
Overwt
Obese I
Obese II-III
Uretsky et a. Am J Med 2007; 120: 863-870
Obesity Paradox: Beyond Heart Failure • Heart Failure • End Stage Renal Disease on Hemodialysis • Rheumatoid Arthritis • Chronic Obstructive Pulmonary Disease • AIDS • Malignancy • The Elderly • Coronary Artery Disease • Diabetes Estimated 45-50 million Americans
All Cause Mortality in the General Population Analysis of 97 studies including 2.88 million individuals in the
OverObese I Obese II weight
BMI
<25
Flegal. Journal of the American Medical Association 2013
25-<30
30-<35
>=35
What does BMI tell us?
Wall Street Journal January 26, 2010
What does BMI tell us? Body Fat (%) Variations in US Men and Women with BMI of 25 kg/m2
Romero-Corral, et al. Int J Obes 2008: 32: 959-966
Hidden Fat
AT = adipose tissue
Despres. Progress in Cardiovascular Disease 2013.
Muscle Mass Matters Stable Coronary Artery Disease Patients
Lavie et al. J Am Coll Cardiol 2012
Healthy Adults Ages 55 and Above
Srikanthan. Am J Med 2014
Fat, Muscle, and Coronary Artery Calcium Score in Women BMI = 29
BMI = 23 BMI = 35
BMI = 26
FAT
HIGH
LOW
HIGH
LOW
MUSCLE
LOW
LOW
HIGH
HIGH
Fitness vs. Fatness on All Cause Mortality: A Meta-Analysis