Inverse relationship between body mass index and coronary artery calcification in patients with clinically significant coronary lesions

Abstract 

Aims

Mounting data support a ‘calcification paradox’, whereby reduced bone mineral density is associated with increased vascular calcification. Furthermore, reduced bone mineral density is prevalent in older persons with lower body mass index (BMI). Therefore, although BMI and coronary artery calcification (CAC) exhibit a positive relationship in younger persons, it is predicted that in older persons and/or those at risk for osteoporosis, an inverse relationship between BMI and CAC may apply. We sought to explore this hypothesis in a large group of patients with coronary artery disease undergoing percutaneous coronary intervention (PCI).

Methods and results

We accessed our single-center registry for 07/01/1999 to 06/30/2009, extracting data on all patients that underwent PCI. To minimize bias we excluded those at the extremes of age or BMI and non-Black/Hispanic/Caucasians, leaving 9993 study subjects (age 66.6±9.9years). Index lesion calcification (ILC) was analyzed with respect to BMI. Comparing index lesions with no angiographic calcification to those with the most severe, mean BMI decreased by 1.11kgm⁻²; a reduction of 3.9% (P<0.0001). By multivariable modeling, BMI was an independent inverse predictor of moderate–severe ILC (m-sILC; odds ratio [OR] 0.967, 95% CI 0.953–0.980, P<0.0001). Additional fully adjusted models identified that, compared to those with normal BMI, obese patients had an OR of 0.702 for m-sILC (95% CI 0.596–0.827, P<0.0001).

Conclusions

In a large group of PCI patients, we identified an inverse correlation between BMI and index lesion calcification. These associations are consistent with established paradigms and suggest a complex interrelationship between BMI, body size and vascular calcification.

Keywords: Aging, Calcium, Vascular calcification, Cardiovascular disease, Obesity, BMI