Impact of obesity on vascular calcification in patients with chronic kidney disease

The aim of this study was to compare vascular calcification (VC) in obese and non-obese chronic kidney disease (CKD) patients, using three methods for measuring VC. The study included 168 consecutive patients with CKD. Patients were divided into two groups by body mass index (BMI) - group 1 (BMI ≥ 30 kg/m ) and group 2 (BMI < 30 kg/m ), and according to estimated glomerular filtration rate (eGFR) - subgroup A (eGFR < 45 mL/min/1.73m ) and subgroup B (eGFR < 45 mL/min/1.73m ). VC was assessed by measuring abdominal aortic calcification (AAC), ankle-brachial index (ABI) and echocardiography. Group 1 patients were older (p = 0.03). There was a relatively low number of diabetics in our study cohort: 41 patients, (24%). The number of diabetics was similar in both groups. The presence of AAC was more common in 1B and 2B than in 1A and 2A groups (p = 0.005 and p = 0.02) and in 1B group compared to 2B group (p = 0.05). In both groups, ABI ≥ 1.3 and ABI < 0.9 were more common in B subgroups. The presence of heart valvular lesions was very high in both groups. Spearman rank-order analysis of every cohort demonstrated significant correlation between AAC and heart valve lesions (Spearman R = 0.3; p = 0.01) and also between AAC and LVH (Spearman R = 0.3; p = 0.004). Analysis of variance of every cohort showed that in patients with ABI ≥ 1.3 and heart valve lesions, Kauppila score was significantly higher than in those with normal heart valves. Our study shows that obesity is not an independent predictor of VC in CKD patients. VC, assessed by three different methods, was more pronounced in obese patients with lower kidney function.