Overview of the Obesity Epidemic

Overview of the Obesity Epidemic

Speaker notes included in notes section below

More than 60% of US Adults Are Overweight or Obese

Flegal K, et al. JAMA. 2002;288:1723-1727. Hedley AA, et al. JAMA. 2004;291:2847-2850.

Obese (BMI ≥ 30)

Overweight (BMI 25 - 29.9)

Assessing Obesity: What Is BMI?

• BMI

– Calculated as weight(kg)/height(m2)

– Evaluates weight relative to height

– Replaced % ideal body weight as the primary criterion for assessing obesity

– Correlates significantly with body fat, morbidity, and mortality

NIH Natl Heart, Lung, and Blood Inst. Obes Res. 1998;6(suppl 2):51S.Willett WC et al. N Engl J Med. 1999;341:427.

Category BMI

Underweight < 18.5

Normal* 18.5 – 24.9

Overweight 25.0 – 29.9

Obesity ≥ 30.0

Class I 30.0 – 34.9

Class II 35.0 – 39.9

Class III ≥ 40.0

Obesity Trends by Gender and Ethnicity

28 29 29

0

10

20

30

40

50

60

White Men Black Men Mexican Men

Pre

vale

nce

of O

besi

ty

.

31

51

40

0

10

20

30

40

50

60

WhiteWomen

Black Women MexicanWomen

Pre

vale

nce

of O

besi

ty

.

Men Women

Flegal K, et al. JAMA 2002;288:1723-1727.

0

2

4

6

8

10

12

14

16

18

NHES II &III1963-70

NHANES I1971-74

NHANES II1976-80

NHANES III1988-94

NHANES1999-2002

Pre

vale

nce

of O

verw

eig

ht

.

Aged 6-11 years Aged 12-19 years

Prevalence of Overweight in Children and Adolescents

Flegal K, et al. JAMA 2002;288:1723-1727. Hedley AA, et al. JAMA 2004;291:2847-2850.

BMI-for-Age Cutoffs for Children and Adolescents

≥ 95th percentile Overweight

85th to < 95th percentile Risk of overweight

< 5th percentile Underweight

Example: 95th Percentile Tracking

Age BMI

2 yrs 19.3 4 yrs 17.8 9 yrs 21.013 yrs 25.1

For Children, BMI Changes with Age

Boys: 2 to 20 years

BMI BMI

BMI BMI

Obesity is Caused by Long-Term Positive Energy Balance

Fatstores

Energyintake

Energyexpenditure

Heritability of Body Weight

Obesity Genetics vs Environment

Restrictiveenvironment

Resistant Prone

“Obesigenic”environment

Obesity Predisposition

BM

I

Ravussin E, Bouchard C. Eur J Pharmacol. 2000;410:131-145.

Responding to the Obesity Epidemic

• Create a child-healthy environment

• Banish junk food from schools

• Reduce food ads directed at children

• Increase opportunities for physical activity

16 oz 32 oz 44 oz 52 oz 64 oz

1 oz ≈ 12 calories

20%

43%

70%

80%

0

10

20

30

40

50

60

70

80

90

1969 1979 1989 1999

American Academy of Pediatrics.

% of Children withDaily Physical Education

0

5

10

15

20

25

30

35

40

TV hours per day (youth report)

Pre

vale

nce

(%)

NHES 1967-1970

NLSY 1990

0 - 1 1 - 2 2 - 3 3 - 4 4 - 5 > 5

Prevalence of Obesity by Hours of TV per Day

NHES Youth Aged 12 to 17 in 1967-1970 and NLSY Youth Aged 10 to 15 in 1990

Medical Complications of Obesity

Pulmonary diseaseabnormal functionobstructive sleep apneahypoventilation syndrome

Nonalcoholic fatty liver diseasesteatosissteatohepatitiscirrhosis

Coronary heart disease Diabetes Dyslipidemia Hypertension

Gynecologic abnormalitiesabnormal mensesinfertilitypolycystic ovarian syndrome

Osteoarthritis

Skin

Gall bladder disease

Cancerbreast, uterus, cervixcolon, esophagus, pancreaskidney, prostate

Phlebitisvenous stasis

Gout

Medical Complications of ObesityIdiopathic intracranial hypertension

Stroke

Cataracts

Severe pancreatitis

Excess fat stores

GenesEnvironment

Activity Food Intake

Diseases due to increased fat cellsize & visceral fat

Stigma

Sleep apnea

OsteoarthritisDiabetes

GB Disease

NAFLD CVD

Cancer

Diseases due to increased fat

mass

Pathogenesis of Health Problems Associated with Obesity

0

0.5

1

1.5

2

2.5

3

< 1

8.5

18.5

- 2

0.4

20.5

- 2

1.9

22.0

- 2

3.4

23.5

- 2

4.9

25.0

- 2

6.4

26.5

- 2

7.9

28.0

- 2

9.9

30.0

- 3

1.9

32.0

- 3

4.9

35.0

- 3

9.9

> 4

0.0

Body Mass Index Interval

Re

lative

Ris

k o

f D

ea

th

White Men

White Women

BMI and Mortality by Ethnic Group The American Cancer Society Study

Calle NEJM 1999;341:1097.

Relative Risk of Death by BMI Levels from the NHANES I, II, & III Surveys

BMI Level Relative Risk by Age Category

25-59 60-69 ≥ 70

< 18.5 1.38 2.30 1.69

18.5 to < 25 1.00 1.00 1.00

25 to < 30 0.83 0.95 0.91

30 to < 35 1.20 1.13 1.03

≥ 35 1.83 1.63 1.17

Flegal et al JAMA;2005:1861

Range of Estimates of Mortality Associated with Overweight

Author YearEstimated excess

deaths

Foege & McGinnis 1993 300,000

Fontaine et al 1999275,000 to

325,000

Mokdad et al 2004 365,000

Flegal et al NHANES I

2005 112,000

Overweight*(BMI 25 - 29.9)

Obese*(BMI > 30)

Female (non-smoker, 40 years of age) 3.29 y 7.08 y

Male (non-smoker, 40 year of age) 3.05 y 5.82 y

Obesity Decreases Life Expectancy:The Framingham Study

Peeters Ann Int Med 2003;138:24-32.

* Compared to a BMI 18.5-24.9 kg/m2

Proportion of Disease Prevalence Attributable to Obesity

Type 2 Diabetes 57%

Gall bladder disease 30%

Hypertension 17%

Cardiovascular disease 17%

Osteoarthritis 14%

Breast Cancer 11%

Uterine Cancer 11%

Colon Cancer 11%Diet, Nutrition and the Prevention of Chronic Diseases. Report of a Joint WHO/FAO Expert Consultation. Geneva, World Health Organization (WHO Technical Report Series, No. 916).

Relationship Between BMI and Risk of Type 2 Diabetes Mellitus

Chan J et al. Diabetes Care 1994;17:961.Colditz G et al. Ann Intern Med 1995;122:481.

Age

-Adj

uste

d R

elat

ive

Ris

k

Body Mass Index (kg/m2)

< 23 24 - 24.9

25 - 26.9

27 -28.9

33 -34.9

0

25

50

75

100

1.02.9 4.3 5.0

8.1 15.8

27.6

40.3

54.0

93.2

< 22 23 - 23.9

29 -30.9

31 -32.9

35 +

1.0 1.52.2

4.46.7

11.6

21.3

42.1

1.0

Men

Women

Waist Circumference Relative Risk of Type 2 DM

< 28 inches 1.0

28 - 29 1.2

30 - 31 2.8

32 - 33 4.0

34 - 35 4.8

36 - 37 5.5

> 38 6.2

*Controlled for age, family history of diabetes, exercise, smoking, saturated fat intake, calcium, potassium, magnesium, and glycemic index.

Nurses’ Health Study: Waist Circumference Directly Related to Risk for Type 2 Diabetes

Carey et al. Am J Epidemiol. 1997;145:614.

Characteristics of the Metabolic Syndrome

• Abdominal obesity• Glucose intolerance• High triglycerides• Low HDL-cholesterol• High blood pressure• Insulin resistance

• Microalbuminuria• Small dense LDL• Inflammatory markers• Thrombotic factors• Endothelial

dysfunction• Hyperuricemia

Full members Wannabes

Abdominal Obesity

Abdominal Adiposity

Courtesy of Steven Smith, M.D.

Visceral Subcutaneous

Subcutaneous Fat

Abdominal Muscle Layer

Intra-abdominal Fat

Visceral Adiposity:The Critical Adipose Depot

Metabolic Syndrome: NCEP ATP III compared to IDF

* requires presence of 3 or more criteria** requires central adiposity and presence of 2 more criteria

Risk Factor ATP III * IDF**

Central Adiposity (defined by waist circumference)

M (waist) > 40 in (> 102 cm) ≥ 37 in (≥ 94 cm)

F > 35 in (> 88 cm) ≥ 31.5 in (≥ 80 cm)

Triglycerides ≥ 150 mg/dL (≥ 1.7 mmol/L)

≥ 150 mg/dL (≥ 1.7 mmol/L)

HDL-C M < 40 mg/dL

(< 1.03 mmol/L)< 40 mg/dL (< 1.03 mmol/L)

F < 50 mg/dL (< 1.0 mmol/L)

< 50 mg/dL (< 1.0 mmol/L)

Blood Pressure ≥ 130/≥ 85 mm Hg ≥ 130/≥ 85 mm Hg

Fasting Glucose ≥ 110 mg/dL (≥ 6.1 mmol/L)

≥ 100 mg/dL (≥ 5.6 mmol/L)

Age-Adjusted Prevalence of the Metabolic Syndrome

Ford JAMA 2002;287:356-9.

Among 8814 Adults Age > 20

Mortality from Cancer in American Men and Women

Calle NEJM 2003;348:1625.

Men Women

• Liver• Pancreas• Stomach/Esophagus• Colon/Rectum• Gallbladder• Multiple Myeloma• Kidney• Non-Hodgkin’s• Prostate

• Uterus• Kidney• Cervix• Pancreas/Esophagus• Gallbladder• Breast• Non-Hodgkin’s• Liver• Ovary• Colon/Rectum

Other Increased Risks

• Kidney stones• Complications of pregnancy• Sleep disorders• Osteoarthritis• Stigmatization

The Interheart Study: Risk of MI

FactorOdds Ratio

Population Attributable Risk

Abdominal Obesity (WHR)+ 2.24 33.7

Diabetes+ 3.08 12.3

Hypertension+ 2.48 23.4

ApoB/ApoA1+ 3.87 54.2

Smoking* 2.27 36.4

Psychosocial+ 2.51 28.8* Adj for Age, Sex & Geography+ Adj Age, Sex & Smoking

Yusuf et al Lancet 2004;364-352.

BMI and Physical Functioning (SF-36)The Nurses Health Study

BMI Categories Relative Risk

< 21.9 0.94

22 - 23.9 1.00

24 - 24.9 1.05

25 - 27.9 1.23

28 - 29.9 1.49

30 - 34.9 1.66

35 - 39.9 2.08

> 40 3.08

Coakley et al IJO 1998;22:958-963.

Psychosocial Status of Obese Individuals

• Most obese individuals have normal psychological status

• Persons who seek weight loss report greater distress

• Patients at greatest risk of depression:– Women

– Extreme obesity (BMI ≥ 40 kg/m2)

– Binge eating disorder (BED)

Friedman & Brownell. Psych Bull 1995;117:3-20.

Risk of Major Depression with Extreme Obesity

Onyike, et al. Amer J Epidemiology 2003;158:1139-1147.

1.13 1 0.961.33

1.9

4.63

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

< 18.5 18.5 - 24.9 25 - 29.9 30 - 34.9 35 - 39.9 > 40

Body Mass Index (kg/m2)

Odd

s R

atio

Bodily Pain and Depression in Obese Individuals (N = 306)

0

2

4

6

8

10

12

14

16

18

20

40 - 49.9 50 - 59.9 60 +

Body Mass Index

Not Impaired

Impaired

Fabricatore AF. Obes Surg 2005; 15:304-309.

BD

I-II

Sco

re

Bodily Pain:

Medical Benefits of Modest Weight Loss

• Reduces mortality• Lowers conversion rate to diabetes• Improves blood pressure• Reduces risk factors for CHD• Lowers lipids• Improves sleep apnea

Diabetes Prevention Program Research Group. N Engl J Med. 2002;346,393-403.

Diabetes Prevention Program

40

30

20

10

00 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Placebo

Metformin

Lifestyle

Cum

ulat

ive

Inci

denc

eof

Dia

bete

s (%

)

Year

Small Weight Losses Are BeneficialThe Diabetes Prevention Program

-8

-7

-6

-5

-4

-3

-2

-1

0

1

Wei

ght C

hang

e in

DP

P (

Kg)

0 6 12 18 24 30 36 42 48

Months in study

Lifestyle

+

Placebo

Reduces Risk of Diabetes by 58%

DPP NEJM 2002;346:393-402

Plasma Lipids Improve With Weight Loss

Meta-analysis of 70 Clinical Trials

*P0.05.LDL-C=low density lipoprotein cholesterol; HDL-C=high-density lipoprotein cholesterol; TG=triglycerides.

Dattilo et al. Am J Clin Nutr 1992;56:320.

-0.06

-0.04

-0.02

0.00

0.02

TotalCholesterol LDL-C TG

HDL-C(weight stable)

HDL-C (actively losing)

m

mol

/L p

er k

g of

Wei

ght

Loss

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5 m

g/dL per kg of Weight Loss*

**

*

*

Peppard et al. JAMA 2000;284:3015.

Change in Body Weight (%)

-20 to < -10(n = 22)

-10 to < -5(n = 39)

-5 to < +5(n = 371)

+5 to < +10(n = 179)

+10 to +20(n = 79)

6

4

2

0

-2

-4

Mea

n C

hang

e in

AH

I (E

vent

s/h)

Effect of Weight Change on Apnea-Hypopnea Index (AHI)

The Economics of Obesity

Economic Burden of Obesity Similar to Other Chronic Diseases

Billions, $

Obesity 1 75.0

Type 2 Diabetes* 2 73.7

Coronary heart disease 3 52.4

Hypertension 4 28.2

Arthritis 5 23.9

Breast Cancer 6 7.1

1 Finkelstein EA, Obes Res 2004;12 4Hodgson TA et al. Med Care 2001;39:599 2 ADA Diabetes Care, 2003;26:917 5 Yelin & Callahan. Arthritis Rheum 1995;38:13513 Hodgeson TA et al. Medical Care 1999:37:994. 6Brown ML, et al. Medical Care; 2002;40(suppl): IV-

104Courtesy of Anne Wolf, MS, RD

Direct cost of chronic diseases in the U.S. ($2003)

Cost Difference

• 2.3% - Cost increase for each higher BMI unit

• 52.9% - Cost increase for each major associated co-morbidity

Raebel, M. et al. Health Services Use and Health Care Costs of Obese and Non-obese Individuals. Arch Intern Med 2004; No.19. Vol.164: 2135-2140. Oct.25,2004

Obesity Effect on Expected Lifetime Medical Care Costs in Women

0

10,000

20,000

30,000

40,000

Co

sts

($)

37.5 32.5 27.5 22.5

35 - 4445 - 54

55 - 64

BMI (kg/m2)

Age

*Total cost of 8 diseases: CHD, type 2 DM, hypertension, hypercholesterolemia, stroke, gallbladder disease, osteoarthritis of knee, endometrial cancer.

Adapted from Thompson D et al. Arch Intern Med 1999;2177-2183.

Expected Lifetime Medical Care* Savings of Sustained 10% Weight Loss by

Age and Initial BMI (Women)

0

1000

2000

3000

4000

5000

6000

Co

sts

($)

37.5 32.5 27.5

35 - 44

45 - 54

55 - 64

BMI (kg/m2)

Age

*Total cost of 5 diseases: CHD, type 2 DM, hypertension, hypercholesterolemia, and stroke. Adapted from Oster G, et al. Am J Public Health 1999;89:1536-1542.

Childhood/Adolescent Health Costs

• $9 – $20: Cost of a single day of absenteeism for a student

• 9 days: Median # sick days away from school for the most overweight students

• Obesity associated annual hospital costs for children and youth more than tripled over the last two decades

• $35 million in1979 – 1981

• $127 million in 1997 – 1999

Action for Healthy Kids- The Learning Connection- Value of Improving Nutrition and Physical Activity in Our Schools.

Preventing Childhood Obesity: Health in the Balance. 2005. Institute of Medicine. Childhood Obesity Prevention Study.

• Obesity medications produced substantial weight loss

• Drug cost savings for obesity co-morbid conditions

• Subjects were taking medications for:– Diabetes

– Hyperlipidemia

– Hypertension

• Pharmaceutical cost computed for:– Weight loss

– Cardiac risk reduction

– Lipid reduction

– Glucose reduction

Greenway, FL.. Ryan, DH. Bray, GA. Pharmaceutical Cost Savings of Treating Obesity with Weight Loss Medications. Obesity Research. 1999; 7: 523-531.

Obesity Medications

Conclusions

• Obesity is a growing epidemic in the United States and worldwide

• The prevalence of type 2 diabetes and obesity in children/adolescents has dramatically increased

• The risk of comorbid conditions increases as obesity increases.

• The economic burden of obesity is great, and increases as obesity increases