Does waist circumference predict disease risk beyond metabolic risk factors and body mass

index?

Peter M. Janiszewski, Ian Janssen, and Robert RossSchool of Kinesiology and Health Studies

Queen’s University

Ontario

2007 Obesity Society Annual Scientific Meeting October 21st

Relationship Between BMI and the Risk of Death

Stevens et al., N Engl J Med 1998.

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6 45-54 yrs

55-64 yrs

65-74 yrs

75-84 yrs

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.645-54 yrs

55-64 yrs

65-74 yrs

75-84 yrs

Rel

ativ

e R

isk

Rel

ativ

e R

isk

Body Mass Index Body Mass Index

Women Men<1

9.019

.0-21

.922

.0-24

.925

.0-26

.927

.0-28

.929

.0-31

.9

<19.0

19.0-

21.9

22.0-

24.9

25.0-

26.9

27.0-

28.9

29.0-

31.9

Obesity: A heterogeneous condition

≠

Central ObesityCentral Obesity Peripheral ObesityPeripheral Obesity

Vague 1956, AJCN

Men <102 cm ( < 40 in) >102 cm ( > 40 in) BMI (kg/m2) Class Women < 88 cm ( < 35 in) > 88 cm ( > 35 in)

Overweight 25.0 - 29.9 Increased HighObesity 30.0 - 34.9 I High Very HighObesity 35.0 - 39.9 II Very High Very HighExtreme Obesity > 40 III Extremely High

Health Risk

NIH National Heart, Lung and Blood Institute, 1998, Obesity Research.

Characterizing Obesity Related Health Risk

BMI + WC = HEALTH RISK

Waist Circumference

0

0.5

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1.5

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2.5

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RR

for C

VD

Low WCMid WC

High WC

Low Mid HighBMI

Rexrode et al. 1998, JAMA

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RR

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Low WCMid WC

High WC

Low Mid HighBMI

Wang et al. 2005, AJCN

Obesity: A heterogeneous condition

Waist Circumference and Cardiometabolic Risk: A Consensus Statement

• “…there is not yet a compelling body of evidence demonstrating that WC provides…sufficient incremental value in predicting diabetes, CVD, and mortality above and beyond that offered by BMI and commonly evaluated cardiometabolic risk factors…”

• “…WC should only be measured if it can provide additional information that influences patient management.”

The Obesity Society, the American Society for Nutrition, and the American Diabetes Association (2007)

Current Investigation• Objective:

– To determine whether WC predicts risk of diabetes and CVD beyond that explained by commonly evaluated cardiometabolic risk factors and BMI

• Research Design:– Subjects: Men and women from the 1999-2004 National Health and

Nutrition Surveys (NHANES)

– Analysis: Logistic regression to calculate the odds of diabetes and CVD according to sex-specific WC tertiles

– Cardiometabolic Risk Factors: blood pressure, triglycerides, LDL and HDL cholesterol, and fasting glucose levels

Results: Subject Characteristics

Variable Total (n = 5882)

Men(n = 3001)

Women(n = 2881)

Age, y 44.2 ± 0.5 43.3 ± 0.5 45.1 ± 0.5

Waist circumference, cm 95.3 ± 0.4 98.5 ± 0.4 92.1 ± 0.5

BMI, kg/m2 27.7 ± 0.1 27.6 ± 0.1 27.8 ± 0.2

Impaired fasting glucose, % 24.6 (1.1) 30.3 (1.4) 19.0 (1.1)

Diabetes, % 8.1 (0.5) 9.2 (0.7) 7.1 (0.5)

Cardiovascular disease, % 7.0 (0.5) 8.0 (0.7) 6.0 (0.6)

Hypertension, % 27.3 (0.9) 26.6 (1.2) 28.1 (1.0)

High LDL-cholesterol, % 21.6 (0.8) 22.8 (0.9) 20.4 (0.1)

Low HDL-cholesterol, % 19.9 (0.8) 27.8 (1.0) 12.0 (0.9)

High triglycerides, % 14.7 (0.6) 17.0 (1.0) 12.4 (0.6)

Results: WC and Risk of Diabetes and CVDResults: WC and Risk of Diabetes and CVDO

dds

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VDLow Med High

Waist Circumference

Low Med High

Waist Circumference

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Adjusted for sex, age, race, and smokingAdjusted for sex, age, race, and smokingAdjusted for sex, age, race, and smoking

Results: WC and Risk of Diabetes and CVDResults: WC and Risk of Diabetes and CVD

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Waist Circumference

Low Med High

Waist Circumference

Adjusted for sex, age, race, and smokingAdjusted for sex, age, race, and smokingAdjusted for sex, age, race, and smoking, metabolic risk factors and BMIAdjusted for sex, age, race, and smoking

Results: BMI and Risk of Diabetes and CVDResults: BMI and Risk of Diabetes and CVD

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BMI

Adjusted for sex, age, race, and smoking

Results: BMI and Risk of Diabetes and CVDResults: BMI and Risk of Diabetes and CVD

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Adjusted for sex, age, race, and smokingAdjusted for sex, age, race, and smokingAdjusted for sex, age, race, and smoking, metabolic risk factors and WCAdjusted for sex, age, race, and smoking

Results: WC, Cardiometabolic Risk Factors and Diabetes Risk

02468

10121416

0 1 2 3+

Number of Cardiometabolic Risk Factors

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Low WCModerate WC

High WC

Ptrend < 0.001 for both WC and risk factors

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Number of Cardiometabolic Risk Factors

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High WC

Results: WC, Cardiometabolic Risk Factors and CVD Risk

Ptrend < 0.001 for risk factors, not significant for WC

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Number of Cardiometabolic Risk Factors

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Results: WC, Cardiometabolic Risk Factors and CVD Risk

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Low Med HighWaist Circumference

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Conclusions

• WC predicts risk of diabetes, but not CVD, beyond that explained by commonly obtained cardiometabolic risk factors and BMI

* p<0.05 vs Control

Effects of Aerobic Exercise (4 mo) With or Without Weight Loss on Waist Circumference in Obese Men and Women

Red

uctio

n in

Wai

st C

ircum

fere

nce

(cm

)

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6

9

Obese Men

*

*

Control WeightLoss

No WeightLoss

Exercise

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*

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Obese Women

Control WeightLoss

No WeightLoss

Exercise

No Changein BMI

No Changein BMI

Ross et al. Ann Intern Med (2000) ; Ross et al. Obesity Research (2004)

Conclusions

• WC predicts risk of diabetes, but not CVD, beyond that explained by commonly acquired cardiometabolic risk factors and BMI

• Thus, WC should be a routine clinical measure for the identification and management of the high-risk, abdominally obese patient