Monocyte counts are negatively associated with ankle-brachial index values in non-dialysis-dependent chronic kidney disease patients

Abstract

Our aim was to determine which leukocyte subtypes are most relevant to ankle-brachial index (ABI) values in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD). The study included 79 NDD-CKD patients aged 62.84 +/- 12.09 years (63.33% men; 26.67% patients with diabetes) and 21 age-matched normal controls. According to the estimated glomerular filtration rate (eGFR) calculated by the CKD-Epidemiology Collaboration equation (CKD-EPI), we classified the study population into 2 groups (21 subjects with NDD-CKD with an eGFR 60-89 mL/min/1.73m(2), 58 subjects with NDD-CKD with eGFR <60 mL/min/1.73 m(2)). ABI was calculated as the ratio of the ankle systolic BP divided by the arm systolic BP using an ABI-form device. An automated hematologic analyzer was used to measure total and differential leukocyte counts. Monocyte counts and monocyte-to-total leukocyte count ratios (MTR) in patients with an ABI value <1.10 were significantly higher than those in patients with an ABI value >= 1.10, respectively. Univariate analyses revealed that mean ABI values were negatively correlated with monocyte count (r= -0.341;p = 0.044), MTR (r= -0.346,p = 0.031). Multivariate linear regression analyses showed that monocyte count was negatively associated with ABI values (beta +/- SE = -1.825 +/- 0.341,p = 0.013). The area under the curve of monocyte counts was 0.695 (95% confidence interval 0.586-0.804,p = 0.002) in predicting an ABI value <1.10. Monocyte counts are negatively associated with ABI values in patients with NDD-CKD without apparent peripheral arterial occlusive disorder (PAOD).