248465 Relationship between homocysteine levels and atherosclerosis in the National Health and Nutrition Examination Survey (NHANES)

Sunday, October 30, 2011

Shikhar Agarwal, MD, MPH, CPH , Internal Medicine Department, Cleveland Clinic, Cleveland, OH
Tarique Zaman, MD , School of Public Health, Case Western Reserve University, Cleveland, OH
Navkaranbir Bajaj, MD , Internal Medicine, Cleveland Clinic, Cleveland, OH
E. Tuzcu, MD FACC , Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH
Samir Kapadia, MD FACC , Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH
Introduction: Elevated homocysteine levels have been shown to be associated with atherosclerosis. Pathophysiologic mechanisms are believed to be different between coronary atherosclerosis and peripheral artery atherosclerosis. We aimed to examine the differences in the prevalence of coronary artery disease (CAD), cerebrovascular disease (CVD) and peripheral artery disease (PAD) across rising homocysteine levels.

Methods: Cross-sectional data from NHANES 1999-2000, 2001-2002, 2003-2004 and 2005-2006 were merged. Homocysteine levels were used to create three categories: normal (<10micromoles/L), borderline (10-15micromoles/L) and elevated (>15micromoles/L). CAD and CVD were determined using standardized questionnaires. PAD was defined as ankle brachial pressure index <0.9. Multivariate logistic regression analysis was performed using CAD, CVD or PAD as outcome and homocysteine category as the independent variable. Results: We observed increased odds of CAD among individuals with borderline [OR (95%CI):1.19(1.01-1.41)] or elevated [OR (95%CI):1.45(1.08-1.96)] homocysteine levels in comparison to those with normal homocysteine levels. Similarly, increased odds of CVD were observed among individuals with borderline [OR (95%CI):1.55(1.10-2.17)] or elevated [OR (95%CI):1.65(1.10-2.46)] homocysteine levels. Since, the odds of PAD were not elevated among the homocysteine categories defined above, we divided entire cohort into 10 quantiles according to the homocysteine levels to determine a cut-point above which the risk of PAD would be elevated. The risk of PAD appeared to increase only at homocysteine levels >27.5micromoles/L.

Conclusions: The risk of CAD and CVD appear to be elevated in patients with homocysteine levels >10micromoles/L. However, the risk of PAD increased only at significantly higher levels of serum homocysteine (>27.5micromoles/L).

Learning Areas:
Biostatistics, economics
Clinical medicine applied in public health

Learning Objectives:
To assess the relationship of coronary artery disease, cerebrovascular disease and peripheral artery disease with rising serum homocysteine concentrations.

Keywords: Chronic Diseases, Cardiorespiratory

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am qualified to present as I possess adequate training in cardiovascular epidemiology and biostatistics and have been responsible for several research projects in the area of cardiovascular epidemiology and clinical research.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.