Abstract P003: Serum Urate and Subclinical Atherosclerosis: The Coronary Artery Risk Development in Young Adults (CARDIA) Study
Background: Elevated serum urate (sUA) has been related to risk of cardiovascular disease (CVD), while evidence is limited among young and apparently healthy populations.
Objective: To examine whether sUA concentration is positively associated with subclinical atherosclerosis as reflected in coronary artery calcified plaque (CAC), aortoiliac artery calcified plaque (AoIC), common carotid intima-media thickness (cCIMT), and carotid stenosis, among young adults.
Methods: The Coronary Artery Risk Development in Young Adults (CARDIA) Study tracked a cohort of 5,115 black and white adults aged 18-30 years since 1985-86 (year 0), with 7 subsequent examinations at approximately 5 year intervals. sUA concentration was assayed at years 0, 10, 15, and 20, while subclinical atherosclerosis was measured at years 15 (i.e. CAC), 20 (i.e. CAC, carotid stenosis, and cCIMT) and 25 (i.e. CAC and AolC). A dietary history questionnaire was administered at year 0, 7 and 20. Logistic and generalized linear regressions were used as appropriate to examine the relations of sUA at year 0 or 20 with subclinical atherosclerosis. sUA was modeled as continuous variable or gender-specific quartiles that were pooled for the analyses. Covariates at the year of sUA measurement were selected and adjusted in the models based on biological relevance and statistically significant confounding effects.
Results: The mean (standard deviation [SD]) year 20 sUA concentrations were 6.61 (1.29) mg/dL in men and 4.95 (1.15) mg/dL in women. Adjusting for year 20 age, sex, race, clinic, education, physical activity, smoking status, and intakes of alcohol, protein and total calories, per SD higher year 20 sUA concentration was associated with 26% (95% confidence interval [CI]=9-44%) and 18% (95%CI=3-34%) higher risk of the presence of CAC at years 20 and 25, respectively. However, further adjustment for year 20 body mass index (BMI) and other metabolic factors (i.e. full model) substantially attenuated these relations. In contrast, the positive associations between year 20 sUA and the presence of AolC at year 25 or cCIMT at year 20 retained statistical significance in the model including BMI and metabolic factors: the odds ratio of year 25 AoIC was 1.38 (95%CI=1.03-1.86) for the highest vs. lowest year 20 sUA quartile; and per SD higher sUA was related to 0.01mm greater year 20 cCIMT (p=0.002). Year 20 sUA was not related to carotid stenosis. Parallel analysis using year 0 sUA as the predictor variable and year 0 covariates found a similar pattern in relation to years 15, 20 and 25 subclinical atherosclerosis markers, which, however, were all attenuated to non-significance in the year 0 full model.
Conclusion: The sUA concentration may be an early biomarker for subclinical atherosclerosis in young adults prior to the development of clinical CVD, operating in part through its relation with BMI and other metabolic factors.
- © 2012 by American Heart Association, Inc.