BACKGROUND AND AIMS:Coronary artery calcification (CAC) is common among patients with chronic kidney disease (CKD) and predicts the risk for cardiovascular disease (CVD). We examined the associations of novel risk factors with CAC progression among patients with CKD. METHODS:Among 1123 CKD patients in the Chronic Renal Insufficiency Cohort (CRIC) Study, CAC was measured in Agatston units at baseline and a follow-up visit using electron beam computed tomography or multidetector computed tomography. RESULTS:Over an average 3.3-year follow-up, 109 (25.1%) participants without CAC at baseline had incident CAC and 124 (18.0%) participants with CAC at baseline had CAC progression, defined as an annual increase of ≥100 Agatston units. After adjustment for established atherosclerotic risk factors, several novel risk factors were associated with changes in CAC over follow-up. Changes in square root transformed CAC score associated with 1 SD greater level of risk factors were -0.20 (95% confidence interval, -0.31 to -0.10; p < 0.001) for estimated glomerular filtration rate, 0.14 (0.02-0.25; p = 0.02) for 24-h urine albumin, 0.25 (0.15-0.34; p < 0.001) for cystatin C, -0.17 (-0.27 to -0.07; p < 0.001) for serum calcium, 0.14 (0.03-0.24; p = 0.009) for serum phosphate, 0.24 (0.14-0.33; p < 0.001) for fibroblast growth factor-23, 0.13 (0.04-0.23; p = 0.007) for total parathyroid hormone, 0.17 (0.07-0.27; p < 0.001) for interleukin-6, and 0.12 (0.02-0.22; p = 0.02) for tumor necrosis factor-α. CONCLUSIONS:Reduced kidney function, calcium and phosphate metabolism disorders, and inflammation, independent of established CVD risk factors, may progress CAC among CKD patients.

Apparent treatment-resistant hypertension (ATRH) is highly prevalent and associated with cardiovascular disease risk in patients with chronic kidney disease. We analyzed the association of inflammatory biomarkers with ATRH and its complications in patients with chronic kidney disease. ATRH was defined as blood pressure ≥140/90 mm Hg while taking ≥3 antihypertensive medications or blood pressure <140/90 mm Hg while taking ≥4 medications. Analyses included 1359 CRIC study (Chronic Renal Insufficiency Cohort) participants with ATRH and 2008 hypertensive participants without. Logistic regression was used to examine cross-sectional associations of inflammatory biomarkers and ATRH adjusting for demographic, lifestyle, and clinical risk factors and treatments. Cox proportional hazards models were used to assess the impact of inflammatory biomarkers on associations of ATRH with composite cardiovascular disease and mortality beyond conventional risk factors. Multivariable-adjusted odds ratio (95% CI) of ATRH for the highest tertile versus the lowest tertile of inflammatory biomarker levels was 1.29 (95% CI, 1.05-1.59) for IL (interleukin)-6, 1.49 (95% CI, 1.20-1.85) for TNF-α (tumor necrosis factor-α), and 0.77 (95% CI, 0.63-0.95) for TGF-β (transforming growth factor-β). High-sensitivity CRP (C-reactive protein), fibrinogen, IL-1β, and IL-1 receptor antagonist were not significantly associated with ATRH. Adding inflammatory biomarkers to Cox models did not attenuate the significant association of ATRH with cardiovascular disease and mortality. Our findings show higher levels of IL-6 and TNF-α and lower levels of TGF-β were independently associated with odds of ATRH. Targeting specific inflammatory pathways may improve blood pressure control in patients with chronic kidney disease.

RATIONALE & OBJECTIVE:Coronary artery calcification (CAC) is prevalent among patients with chronic kidney disease (CKD) and increases risks for cardiovascular disease events and mortality. We hypothesized that a novel serum measure of calcification propensity is associated with CAC among patients with CKD stages 2 to 4. STUDY DESIGN:Prospective cohort study. SETTING & PARTICIPANTS:Participants from the Chronic Renal Insufficiency Cohort (CRIC) Study with baseline (n=1,274) and follow-up (n=780) CAC measurements. PREDICTORS:Calcification propensity, quantified as transformation time (T50) from primary to secondary calciprotein particles, with lower T50 corresponding to higher calcification propensity. Covariates included age, sex, race/ethnicity, clinical site, estimated glomerular filtration rate, proteinuria, diabetes, systolic blood pressure, number of antihypertensive medications, current smoking, history of cardiovascular disease, total cholesterol level, and use of statin medications. OUTCOMES:CAC prevalence, severity, incidence, and progression. ANALYTICAL APPROACH:Multivariable-adjusted generalized linear models. RESULTS:At baseline, 824 (65%) participants had prevalent CAC. After multivariable adjustment, T50 was not associated with CAC prevalence but was significantly associated with greater CAC severity among participants with prevalent CAC: 1-SD lower T50 was associated with 21% (95% CI, 6%-38%) greater CAC severity. Among 780 participants followed up an average of 3 years later, 65 (20%) without baseline CAC developed incident CAC, while 89 (19%) with baseline CAC had progression, defined as annual increase≥100 Agatston units. After multivariable adjustment, T50 was not associated with incident CAC but was significantly associated with CAC progression: 1-SD lower T50 was associated with 28% (95% CI, 7%-53%) higher risk for CAC progression. LIMITATIONS:Potential selection bias in follow-up analyses; inability to distinguish intimal from medial calcification. CONCLUSIONS:Among patients with CKD stages 2 to 4, higher serum calcification propensity is associated with more severe CAC and CAC progression.