Abstract P347: The Relationship Between Renal Artery Calcium and Kidney Function: the Multi-Ethnic Study of Atherosclerosis
Background: Renal Artery Calcium (RAC) has been shown to be associated with a higher odds of hypertension (HTN). The purpose of this study was to determine if the presence and extent of RAC is associated with significant differences in several measures of kidney function.
Methods: We analyzed cross-sectional data from the Multi-Ethnic Study of Atherosclerosis (MESA). During MESA follow-up visits 2 and 3, a random subsample of 1226 participants underwent computed tomography (CT) of the abdomen and also had venous blood samples assayed for kidney function. RAC was the primary predictor variable and the following measures of kidney function were the outcome variables: eGFR, cystatin-C, micro and macroalbuminuria and CKD stage. CKD stage was divided into the following groups: stage 1 GFR < 90mL/min, stage 2 GFR 60-89 mL/min, stage 3A GFR 45-59 mL/min, and stage 3B GFR 30-44 mL/min. There were no study participants in the stage 4 category of GFR < 30mL/min. The analyses were adjusted for age, gender, race, height, visceral fat, dyslipidemia, diabetes, cigarette smoking, hypertension, interleukin-6 (IL-6), coronary artery calcium (CAC), abdominal aortic calcium (AAC), renin and aldosterone.
Findings: The average age of this cohort was 66.1 years (SD 9.7) and 44.8% (549 of 1226) were male, 36.3% (445 of 1226) Caucasian, 14.1% (173 of 1226) Chinese-American, 21.6% (265 of 1226) African-American and 28.0% (343 of 1226) Hispanic-American. Compared with those with no RAC, those with RAC > 0 were significantly older but not different by gender or race. After adjustment for age, sex and race, those with RAC > 0 had significantly higher visceral fat, were more likely to have dyslipidemia, diabetes and hypertension, had a higher IL6, and a higher prevalence of CAC and AAC > 0.
In fully adjusted multivariable linear regression models, the presence of RAC was associated with higher creatinine (β = 0.052, p = 0.01) and Cystatin-C (β = 0.052, p < 0.01), as well as a lower eGFR (β = -2.209, p = 0.06). In logistic regression, the presence of RAC was also associated with albuminuria but after adjustment for cardiovascular risk factors including dyslipidemia, diabetes, smoking and hypertension, this association was no longer significant. In fully adjusted ordinal logistic regression, RAC as a continuous variable was associated with increased odds of being in a higher CKD category (β = 1.14, p = 0.05).
Discussion: Our results suggest a modest relationship between RAC and kidney function, when measured by creatinine, Cystatin-C, eGFR and CKD stage. As such, the identification of RAC on abdominal CT scans obtained as part of clinical practice may be considered in the prevention of chronic kidney disease.
Author Disclosures: D. Vashishtha: None. R. McClelland: None. J. Ix: None. D. Rifkin:None. N. Jenny: None. M. Allison: None.
- © 2017 by American Heart Association, Inc.