Vascular calcifications, vertebral fractures and mortality in haemodialysis patients

Abstract

Background: Vascular calcifications and the bone fractures caused by abnormal bone fragility, also called osteoporotic fractures, are frequent complications associated to chronic kidney diseases (CKD). The aim of this study was to investigate the association between vascular calcifications, osteoporotic bone fractures and survival in haemodialysis (HD) patients. Methods: A total of 193 HD patients were followed up to 2 years. Vascular calcifications and osteoporotic vertebral fractures (quoted just as vertebral fractures in the text) were assessed by thoracic, lumbar spine, pelvic and hand X-rays and were graded according to their severity. Clinical, biochemical and therapeutical data gathered during the total time spent on HD were collected. Results: The prevalence of aortic calcifications was higher in HD patients than in a random-based general population (79% versus 37.5%, p<0.001). Total time on any renal replacement therapy (RRT) and diabetes were positively associated to a higher prevalence of vascular calcifications. In addition to these factors, time on HD was also positively associated to the severity of vascular calcifications, and higher haemoglobin levels were associated with a lower prevalence of severe vascular calcifications in large and medium caliber arteries. The prevalence of vertebral fractures in HD patients was similar to that of the general population (26.5% versus 24.1%). Age and time on HD showed a positive and statistically significant association with the prevalence of vertebral fractures. Vascular calcifications in the medium caliber arteries were associated to a higher rate of prevalent vertebral fractures. In women, severe vascular calcifications and vertebral fractures were positively associated to mortality [RR=3.2 (1.0-10.0) and RR=4.8 (1.7-13.4)[respectively]. Conclusions: Positive associations between vascular calcifications, vertebral fractures and mortality have been found in patients on HD.