Assessment and risk factors of abdominal aortic calcification in peritoneal dialysis patients

Abstract

Objectives To evaluate the incidence and risk factors of abdominal aortic calcification (AAC) in chronic kidney disease (CKD) stage 5 patients undergoing peritoneal dialysis (PD). Methods Eligible CKD stage 5 patients undergoing PD in Renji Hospital, Shanghai Jiao Tong University School of Medicine were enrolled in present study. Demographic features, blood pressure, laboratory parameters, residual renal function (RRF), dialysis adequacy and medication were determined. Lateral abdominal X-ray plain film was used to assess AAC, and abdominal aortic calcification score (AACS) was calculated. Risk factors for AAC were analyzed by Logistic regression. Results A total of 206 PD patients aged (55.6 ± 15.0) years with median PD duration 20 (8, 44) months were enrolled in present study. Among them, 108 (52.4%) patients were males and 35(17.0%) complicated with diabetes mellitus. AAC was presented in 118 (57.3%) patients, and 49 (23.8%) patients had severe calcification (calcification involving more than 3 lumber segments). Compared to those without AAC, patients with AAC were elder [(62.3±11.9) years old vs (46.7±13.9) years old, P < 0.01], had longer PD duration [28(11, 57) months vs 16(7, 29)months, P <0.01], higher diabetic nephropathy (18.6% vs 6.8%, P <0.05) and diabetic incidence (23.7% vs 8.0%, P <0.01) proportion, higher pulse pressure [52.0(44.0, 66.3) mmHg vs 48.0(40.0, 58.0) mmHg, P <0.05], lower diastolic blood pressure[(81.4±11.7) mmHg vs (88.6±14.6) mmHg, P <0.01] and mean arterial pressure [(99.6± 13.3) mmHg vs (104.8±15.1) mmHg, P <0.05], higher high-sensitivity C-reactive protein [2.8(0.7, 5.6) mg/L vs 1.1(0.3, 4.4) mg/L, P <0.05], lower serum albumin [(36.9±4.5) g/L vs (38.7±4.5) g/L, P< 0.01], pre-albumin [(373.2±89.1) g/L vs (404.9±74.7) g/L, P<0.01], high density lipoprotein [1.1(0.9, 1.4) mmol/L vs 1.3(0.9, 1.5) mmol/L, P<0.05], and total creatinine clearance rate [(59.1 ± 18.9) L·week-1·(1.73 m2)-1 vs (67.8±29.8) L·week-1·(1.73 m2)-1, P <0.05]. Logistic regression showed that old age (OR=1.104, 95%CI 1.071-1.138, P <0.01) and high calcium phosphorus product (OR=1.467, 95% CI 1.037-2.074, P <0.05) were independent risk factors for AAC, while RRF (OR=0.858, 95%CI 0.740-0.995, P <0.05) as a protective factor. Conclusions AAC is prevalent in CKD stage 5 patients undergoing PD. Advancing age and high calcium phosphorus product are independent risk factors for AAC, while high RRF is a protective factor. The lateral abdominal X-ray plain film is an inexpensive, simple and promising tool for assessment of AAC, even though its prognostic value of PD patients requires more follow-up studies. Key words: Peritoneal dialysis; Aorta, abdomina; Vascular calcification; Lateral abdominal X-ray plain film