1. Change in Abdominal Obesity & Risk of Coronary Calcification Siamak Sabour, MD, MSc, DSc, PhD, Postdoc Clinical Epidemiologist Persian International Epidemiology Network (PIEPNET)

2. 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 2Sabour S, MD, MSc, DSc, PhD, Postdoc

3. Introduction Obesity is a major health problem in industrialized countries. The prevalence of overweight and obesity has increased dramatically in last decades. 3Sabour S, MD, MSc, DSc, PhD, Postdoc

4. Introduction Visceral or abdominal obesity is an important indicator of cardiovascular risk. Atherosclerosis is a key factor in the pathogenesis of cardiovascular disease. 4Sabour S, MD, MSc, DSc, PhD, Postdoc

5. Introduction Atherosclerosis in the coronary arteries (CAC) can be accurately and reproducibly assessed with Multi- Detector Computed Tomography (MDCT) in a non-invasive way. 5Sabour S, MD, MSc, DSc, PhD, Postdoc

6. Introduction CAC is increasingly used as a marker of disease risk or of subclinical atherosclerosis. The presence of CAC is a significant predictor of subsequent cardiovascular disease and total mortality. 6Sabour S, MD, MSc, DSc, PhD, Postdoc

7. Introduction Randomized Controlled Trials (RCT) have indicated that weight loss may benefit levels of risk factors; however, trials were usually of modest duration. 7Sabour S, MD, MSc, DSc, PhD, Postdoc

8. PURPOSE To determine the impact of change in abdominal obesity, as assessed by change in WHR during 9 years, on risk of coronary artery calcification (CAC). 8Sabour S, MD, MSc, DSc, PhD, Postdoc

9. DESIGN Cohort (longitudinal) study 9Sabour S, MD, MSc, DSc, PhD, Postdoc

10. SUBJECTS 573 postmenopausal women selected from a population based cohort study. (PROSPECT study) 10Sabour S, MD, MSc, DSc, PhD, Postdoc

11. METHODS Data on 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). 11Sabour S, MD, MSc, DSc, PhD, Postdoc

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14. METHODS The Agatston score was used to quantify coronary artery calcium. Logistic regression models were used to evaluate the relations under study. 14Sabour S, MD, MSc, DSc, PhD, Postdoc

15. METHODS Change in 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 15Sabour S, MD, MSc, DSc, PhD, Postdoc

16. 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 2.7 [95% CI 1.8-4.0] fold increased risk of CAC. 16Sabour S, MD, MSc, DSc, PhD, Postdoc

17. RESULTS Women whose WHR rose over the 9 year period from below the median to above the median had a 2.5 [95%CI 1.4-4.5] fold increased risk of CAC. 17Sabour S, MD, MSc, DSc, PhD, Postdoc

18. Risk factorsMean (SD) _______________________________ Baseline Follow-up (1993-1997) (2002-2004) P value Age (year)57.2 ± 5.266.8 ± 5.5 Body Mass Index (Kg/ m 2 )25.6 ± 4.026.7 ± 4.4<0.001 Waist circumference (cm)82.3 ± 9.486.1 ±11.2<0.001 Hip circumference (cm)105.1 ± 8.2102.1 ± 9.3<0.001 Waist to Hip Ratio0.78 ± 0.050.84 ± 0.07<0.001 Systolic blood pressure (mmHg)131 ± 19136 ± 21<0.001 Diastolic blood pressure (mmHg)78 ± 1072 ± 9<0.001 Pulse pressure (mmHg)52 ± 1464 ± 16<0.001 Cholesterol (mmol/l) (n=95)5.9 ± 0.96.2 ± 1.00.078 LDL cholesterol (mmol/l) (n=95)4.0 ± 0.94.2 ± 0.90.118 HDL cholesterol (mmol/l) (n=95)1.6 ± 0.41.4 ± 0.4<0.001 Glucose (mmol/l) (n=90)4.3 ± 0.95.6 ± 1.0<0.001 Current smoking (%)1811<0.001 Former smoking (%)3744<0.001 Hypertension § 140/90 (%)28270.178 Diabetes (%)16<0.001 General characteristics of study population (n=573) Low Density Lipoprotein, High Density Lipoprotein § Based on systolic, diastolic and history of having hypertension in baseline questionnaire 18Sabour S, MD, MSc, DSc, PhD, Postdoc

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20. Baseline Follow-upParticipantsOR (95% CI) Body Mass IndexModel 1Model 2 Low 25011 HighLow220.97 (0.39-2.46)0.83 (0.32-2.12) LowHigh451.36 (0.68-2.71)1.21 (0.60-2.46) High 2551.12 (0.77-1.63)1.13 (0.80-1.65) Waist circumference Low 24211 HighLow501.46 (0.70 – 3.04)1.35 (0.64 – 2.84) LowHigh382.15 (1.09 – 4.23)1.94 (0.97 – 3.86) High 2351.53 (1.04 – 2.26)1.50 (1.01 – 2.23) Hip circumference Low 24611 HighLow551.17 (0.63 – 2.19)1.14 (0.60 – 2.15) LowHigh331.06 (0.48 – 2.37)1.05 (0.47 – 2.35) High 2310.95 (0.65 – 1.40)0.93 (0.63 – 1.38) Waist to Hip Ratio Low 22711 HighLow491.62 (0.83-3.16)1.70 (0.87-3.33) LowHigh712.48 (1.38-4.46)2.45 (1.35-4.50) High 2242.65 (1.76-3.99)2.56 (1.70-3.89) Risk of coronary calcification in categories of change in obesity markers (BMI, WC, HC and WHR) Model 1= Adjusted for Age Model 2= Adjusted for Age and Smoking at baseline. 20Sabour S, MD, MSc, DSc, PhD, Postdoc

21. CONCLUSION Persistent abdominal obesity as well as an increase in abdominal fat over time relates to an increased risk of coronary atherosclerosis. 21Sabour S, MD, MSc, DSc, PhD, Postdoc

22. 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 22Sabour S, MD, MSc, DSc, PhD, Postdoc

23. 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. 23