Coronary Calcification; Body Mass Index (BMI)

or Waist to Hip Ratio (WHR)

Siamak Sabour, MD, MSc, DSc, PhD, PostdocClinical Epidemiologist

Persian International Epidemiology Network (PIEPNET)

SCIENTIFIC BACKGROUND

• 1994: M.D, I.R. Iran

• 2004: M.Sc, Clinical Epidemiology, Erasmus MC, The Netherlands

• 2006: D.Sc, Clinical Epidemiology, Erasmus MC, The Netherlands

• 2007: Ph.D, Clinical Epidemiology, UMC Utrecht, The Netherlands

• 2008

• Post doc Cardiovascular Epidemiology

Thomas Jefferson University, Philadelphia, PA, USA

• Post doc Pharmacoepidemiology

University of Pennsylvania, Philadelphia, PA, USA

• 2008 until now

Assistant Prof of Clinical Epidemiology & Medicine

Sabous S, MD, MSc, DSc, PhD, Postdoc 2

PURPOSE

To examine the relation between 9 years change in

Body Mass Index (BMI),

Waist-to-Hip Ratio (WHR)

and

risk of coronary artery calcification (CAC).

Sabous S, MD, MSc, DSc, PhD, Postdoc 3

DESIGN

Longitudinal study

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SUBJECTS

573 postmenopausal women selected from a population based cohort study.

Sabous S, MD, MSc, DSc, PhD, Postdoc 5

METHODS

Data on BMI & WHR were collected at

baseline (1993-1997) and follow-up

(2002-2004).

At follow-up, the women underwent a

multi-detector computed tomography

(MDCT) (Philips Mx 8000 IDT16) to

assess coronary artery calcium (CAC).

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7

8

METHODS

The Agatston score was used to quantify

coronary artery calcium.

Logistic regression models were used

to evaluate the relations under study.

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METHODS

Change in BMI & WHR was categorized

into four groups:

• Low at baseline-Low at follow-up (low was defined as below the median)

• High-Low

• Low-High

• High-High

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RESULTS

Compared to subjects whose WHR

remained below the median of the

distribution at both occasions, those with

a WHR above the median at both

occasions had a 2.8 [95% CI 1.5 - 5.7]

fold increased risk of CAC. Sabous S, MD, MSc, DSc, PhD, Postdoc 11

RESULTS

Women whose WHR rose over the 9 year

period from below the median to above

the median had a 2.6 [95%CI 1.3 - 5.2]

fold increased risk of CAC.

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RESULTS

In contrast, change in BMI was

not related to risk of CAC.

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Risk of Coronary Calcification in Categories of Change in BMI & WHR

Baseline Follow-up

Participants

OR (95% CI)

Body Mass Index Model 1 Model 2 Low Low 247 1 1 High Low 22 0.97 (0.39 - 2.46) 0.67 (0.22 – 1.99) Low High 44 1.36 (0.68 - 2.71) 0.81 (0.33 – 1.96) High High 250 1.12 (0.77 - 1.63) 0.92 (0.43 – 1.95)

Waist to Hip Ratio Low Low 224 1 1 High Low 49 1.62 (0.83 - 3.16) 1.62 (0.76 – 3.42) Low High 71 2.48 (1.38 - 4.46) 2.58 (1.29 – 5.17) High High 219 2.65 (1.76 - 3.99) 2.80 (1.52 – 5.17)

Model 1= Adjusted for Age

Model 2= Full Model (Adjusted for Age and Changes in WC, HC, WHR, BMI, SBP, DBP and Smoking)

Sabous S, MD, MSc, DSc, PhD, Postdoc 14

CONCLUSION

Change in WHR over time

relates to

an increased risk of CAC.

However, BMI has no effect on that.

Sabous S, MD, MSc, DSc, PhD, Postdoc 15

Acknowledgments

Prof. Diederick. E. Grobbee, MD, PhD

Prof. Mathias Prokop, MD, PhD

Dr. Yvonne. T. van der Schouw, PhD

Prof. Michiel. L. Bots, MD, PhD

1. Julius Centre, University Medical Centre Utrecht, The Netherlands

2. Radiology Department, University Medical Center Utrecht, The Netherlands

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CONCLUSION

Changes in Waist-to-Hip Ratio (WHR)

relates to an

increased risk of CAC.

However, Body Mass Index (BMI), has no

effect on that.

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