Impact of obesity on coronary artery calcification examined by electron beam computed tomographic scan

Obesity is highly associated with cardiovascular disease (CVD). The early and non-invasive diagnosis method for asymptomatic obese is desirable. The aim of this study was to examine the impact of obesity on coronary artery calcification (CAC) by electron beam computed tomographic (EBCT) scan.

A total of 465 subjects (i) aged between 40 and 65 years, (ii) being Chinese, (iii) without clinical or historical angiographic obstruction or arrhythmia and (iv) without family history of CVD were enrolled in this study. All the subjects were assigned to one of the EBCT CAC score categories according to the quartiles: quartile 1 (<25%), quartile 2 (25-49%), quartile 3 (50-75%) and quartile 4 (>75%), for further assessment and comparison. The main outcome evaluated is the difference in CAC scores between obese [body mass index (BMI): > or =30 kg/m(2)] and healthy (BMI: 18.5-25.0 g/m(2)) BMI groups. The trends of the characteristics in CAC quartile groups and the odds ratios (ORs) were also evaluated.

The mean of CAC scores between the obese and the healthy BMI groups showed significant difference (p = 0.05). The obese subjects had higher ORs (1.0-5.8 times) than those with BMI < 23 kg/m(2), and male had higher ORs (1.1-3.6 times) than female, to develop the high CAC score quartile group.

This study demonstrated that the obese BMI group has a higher mean of CAC scores than the healthy BMI group of middle-aged, asymptomatic, Chinese adults. The obese males have higher risk of developing high CAC scores, which might induce CVD.