Background A prospective follow-up study was conducted to examine the relationship between 9 year change in abdominal obesity and risk of coronary artery calcification (CAC).

Methods Data on coronary risk factors for 573 postmenopausal women were collected at baseline (1993–1997) and follow-up (2002–2004). At follow-up, the women underwent a multidetector CT to assess coronary calcium using the Agatston score. Markers of abdominal obesity were waist and hip circumference, waist-to-hip ratio (WHR) and body mass index.

Results Compared to subjects whose waist circumference remained below the median at both occasions, those with a waist above the median had a 1.5-fold (95% CI 1.0 to 2.3) increased risk of CAC. Women whose waist rose over the 9 year period had a 2.2-fold (95% CI 1.1 to 4.2) increased risk of CAC, whereas women whose WHR became lower had a non-significant 1.5-fold increased risk of CAC (95% CI 0.7 to 3.0). In contrast, change in body mass index or hip circumference was not related to risk of CAC.

Conclusion This study supports the existing evidence that persistent abdominal obesity, as well as an increase in abdominal fat, relates to an increased risk of coronary atherosclerosis.