Overdiagnosis of Overweight and Obesity: Cultural …...Overdiagnosis of Overweight and Obesity:...

Overdiagnosis of Overweight and Obesity:

Cultural Dogma Trumps Evidence-Based Medicine

Robert A. Gelfand, M.D. Associate Clinical Professor of Medicine

Yale University School of Medicine

4th International Preventing Overdiagnosis Conference

Barcelona, Spain

20-22 September 2016

-- Wallis Simpson, 1896-1986

(American socialite, Duchess of Windsor)

“You can never be too

rich or too thin.”

The Oxford Dictionary of Quotations. Ed. Elizabeth Knowles. Oxford University Press, 2004.

A Simple Message

“The greater the BMI, the greater

the risk of CVD, type 2 diabetes,

and all-cause mortality.”

A Simple Message

-- 2013 Obesity Guidelines, Recommendation #1: Advice for adult patients

“…if you looked at any epidemic -- whether it’s

influenza, or plague from the Middle Ages -- they are

not as serious as the epidemic of obesity in terms of

the health impact on our country and our society.”

-- Julie L. Gerberding, Director of the Centers for Disease Control

and Prevention, 2003

(The 1918-9 influenza epidemic killed 40 million people worldwide)

VERY Serious

(The 1348 plague killed 30% of the population of Europe)

2013 Poll: “Worst Health Problem”

Overweight-Obesity: Reweighing the Evidence

• Does mortality increase as body weight increases throughout the overweight-obesity BMI range?

• Is obesity consistently associated with worsened clinical outcomes?

• Does obesity strongly predict cardiac risk?

• Does medical treatment of obesity improve clinical outcomes?

• Does medicalization of obesity do harm?

•

QUESTIONS:

• Does mortality increase as body weight increases throughout the overweight-obesity BMI range?

• Is obesity consistently associated with worsened clinical outcomes?

• Does obesity strongly predict cardiac risk?

• Does medical treatment of obesity improve clinical outcomes?

• Does medicalization of obesity do harm?

•

QUESTIONS:

Overweight-Obesity: Reweighing the Evidence

Classification by Body Mass Index

Category BMI

Underweight < 18.5

Normal Weight 18.5 to <25

Overweight 25 to <30

Obesity, mild (I) 30 to <35

Obesity, moderate (II) 35 to <40

Obesity, extreme (III) > 40

BMI = Weight (kg) / Height (m)2

Weight Categories, US Population

Normal Weight

Overweight Obesity

JAMA, Jan 2013; 309:71-82

All-Cause Mortality by Standard BMI Categories

Meta-Analysis – JAMA, 2013

97 studies; 2.8 million people; 270,000 deaths

BMI Category Hazard Ratio

18.5 to <25 (Normal) 1

25 to <30 (Overweight) 0.94 *

30 to <35 (Obesity I) 0.95

> 35 (Obesity II, III) 1.29 *

* Significant difference vs. Normal BMI category

Flegal et al., JAMA 2013; 309:71-82

Only Above BMI of 35 does Obesity Predict Increased Mortality

Normal Weight

Overweight Obesity

BMI ≥ 35

• Does mortality increase as body weight increases throughout the overweight-obesity BMI range?

• Is obesity consistently associated with worsened clinical outcomes?

• Does obesity strongly predict cardiac risk?

• Does medical treatment of obesity improve clinical outcomes?

• Does medicalization of obesity do harm?

•

QUESTIONS:

Overweight-Obesity: Reweighing the Evidence

“Obesity Paradox” -- Higher BMI Associated with Better Clinical Outcomes

(J Am Coll Cardiol 2009;53:1925-32)

MEDLINE Search: Citations with

“Obesity Paradox” in Title or Abstract

• Does mortality increase as body weight increases throughout the overweight-obesity BMI range?

• Is obesity consistently associated with worsened clinical outcomes?

• Does obesity strongly predict cardiac risk?

• Does medical treatment of obesity improve clinical outcomes?

• Does medicalization of obesity do harm?

•

QUESTIONS:

Overweight-Obesity: Reweighing the Evidence

Cardiac Risk Assessment Scoring Systems

• Framingham (1998)

• ATP-III (2001)

• Pooled Cohort Equations (2013)

(New ACC/AHA statin guidelines)

Risk Factors:

Age, Sex, Systolic-BP, Smoking, Total-

Chol, HDL-Chol, Diabetes, anti-HTN-rx

None Use Obesity (BMI) in Calculating Cardiac Risk

The Lancet, Early Online Publication 11 March 2011

Cardiovascular Disease Risk: Adiposity Measures vs. Conventional Risk Factors

Conclusion:

BMI, waist circumference, and waist-to-hip ratio, assessed singly or in

combination, do not importantly improve cardiovascular risk prediction

beyond blood pressure, diabetes history, smoking, and lipids.

• Does mortality increase as body weight increases throughout the overweight-obesity BMI range?

• Is obesity consistently associated with worsened clinical outcomes?

• Does obesity strongly predict cardiac risk?

• Does medical treatment of obesity improve clinical outcomes?

• Does medicalization of obesity do harm?

•

QUESTIONS:

Overweight-Obesity: Reweighing the Evidence

NIH Look AHEAD Trial N Engl J Med 2013; 369:145-54

NIH Look AHEAD Trial: Funding NEJM 2013; 369:145-54

• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

• National Heart, Lung, and Blood Institute

• National Institute of Nursing Research

• Office of Research on Women’s Health

• National Center for Minority Health and Health Disparities

• Indian Health Service

• Centers for Disease Control and Prevention (CDC)

NIH Look AHEAD Trial: Summary NEJM 2013; 369:145-54

• Subjects: T2DM, age 59±7, BMI 36±6

• 28,622 pre-screened, 9,045 screened

• N = 5145 randomized

- Intensified Lifestyle Intervention (calorie restriction + exercise) (n=2,570)

- Usual diabetes education (n=2,575)

• ILI: weekly counseling sessions for first 6 months; twice monthly for next 6 months; monthly thereafter; vs. usual diabetes education (~3 sessions/year)

• 9.6-year median follow-up (low dropout rate, ~4% each group)

• Primary Composite Endpoint: CV Death, nonfatal MI or CVA, or hospitalization for angina

NIH Look AHEAD Trial: Significant Weight Loss For 10 Years

NEJM 2013; 369:145-54.

NIH Look AHEAD Trial: Cardiac Events: No Benefit of Weight Loss

NEJM 2013; 369:145-54.

NIH Look AHEAD Trial Halted: No Benefit of Weight Loss on Cardiac Events

• Does mortality increase as body weight increases throughout the overweight-obesity BMI range?

• Is obesity consistently associated with worsened clinical outcomes?

• Does obesity strongly predict cardiac risk?

• Does medical treatment of obesity improve clinical outcomes?

• Does medicalization of obesity do harm?

•

QUESTIONS:

Overweight-Obesity: Reweighing the Evidence

Medicalization of Obesity May Do Harm

“Fat people know that they are fat. You don’t need to tell us; society’s been doing that our whole lives. Many of us have been traumatised by constant reminders about weight loss culture—about how shameful you seem to find our bodies.”

“Losing Weight – An Ill-Fated New Year’s Resolution”

Kassirer JP and Angell M: N Engl J Med 1998: 338:52-54. (Editorial, Jan 1, 1998)

Given the enormous social pressure to lose weight, one might suppose there is clear and overwhelming evidence of the risks of obesity and the benefits of weight loss. Unfortunately, the data linking overweight and death, as well as the data showing the beneficial effects of weight loss, are limited, fragmentary, and often ambiguous.

Given the ambiguous benefits of weight loss, why are physicians and public health officials joining in the general enthusiasm for losing weight? One reason for the medical campaign against obesity may have to do with a tendency to medicalize behavior we do not approve of. In this age of political correctness, it seems that obese people can be criticized with impunity, because the critics are merely trying to help them. Some doctors take part in this blurring of prejudice and altruism by overstating the dangers of obesity and the redemptive powers of weight loss.

• Does mortality increase as body weight increases throughout the overweight-obesity BMI range?

• Is obesity consistently associated with worsened clinical outcomes?

• Does obesity strongly predict cardiac risk?

• Does medical treatment of obesity improve clinical outcomes?

• Does medicalization of obesity do harm?

•

QUESTIONS:

Unproven

Probably Yes

No

No

No

Overweight-Obesity: Reweighing the Evidence

THE END