Abstract 3755: The Association of Indices of Kidney Function with Coronary Artery and Abdominal Aortic Calcification: The Framingham Offspring Study
Background: End stage renal disease is associated with increased coronary artery calcification (CAC). It is uncertain whether moderate chronic kidney disease (CKD), as well as additional indices of kidney function, are associated with CAC or abdominal aortic calcification (AAC).
Methods: We used logistic regression analysis to relate CKD, cystatin-C (CysC), and microalbuminuria (MA) to CAC and AAC obtained using multi-detector computed tomography among Framingham Offspring participants free of CVD (n=1179, mean age 59 years, 55% women). Glomerular filtration rate (eGFR) was estimated using simplified Modification of Diet in Renal Disease Study equation; CKD was defined as eGFR < 59 mL/min per 1.73 m2 (women) and < 64 (men). High CysC was defined as ≥ 1.04 mg/L (women) and 1.11 (men). MA was defined as urinary albumin to creatinine ratio ≥ 30 mg/g. CAC and AAC were defined as ≥ 90th percentile age-and sex-specific cutpoints derived from a healthy referent sample. Models were adjusted for age, sex, systolic blood pressure, hypertension treatment, diabetes, body mass index, total/HDL-cholesterol, lipid treatment and smoking.
Results: Among participants, 6.3% had CKD, 8.3% had MA, and 16.1% high CysC. CKD and MA were not associated with CAC (Odds ratio, OR [95% CI]: 0.8 [0.4 –1.6] p=0.63 and 0.8 [0.4 –1.7] p=0.54 for CKD and MA respectively) or with AAC (OR: 0.9 [0.6 –2.0] p=0.95 and 1.1 [0.5–1.7] p=0.74 for CKD and MA respectively). High CysC was associated with CAC (OR: 1.8 [1.1–2.8] p=0.01) and remained associated upon excluding participants with CKD (OR: 2.0 [1.3–3.4] p=0.004). CysC was not associated with AAC (OR: 0.8 [0.5–1.3] p=0.39). Among participants in middle Framingham risk score quartiles (those in quartiles 2 and 3), high CysC was associated with a 2-fold increased odds of CAC (OR: 2.1[1.2–3.6] p=0.009). In contrast, CysC was not associated with CAC in the low (quartile 1) or high (quartile 4) 10-year CHD risk category (p-value= 0.25, 0.76, respectively).
Conclusion: CysC is associated with CAC, suggesting that the association between CysC and CVD may be mediated via mechanisms related to coronary atherosclerosis. CysC is associated with CAC among those in the middle CHD risk subgroup.