High Prevalence of Vertebral Fractures Assessed by Quantitative Morphometry in Hemodialysis Patients, Strongly Associated with Vascular Calcifications

Abstract

Few studies have provided information on the prevalence of vertebral fractures (VFs) and their risk factors in hemodialysis patients. A multicenter, cross-sectional, observational study was carried out to assess the prevalence of VFs and vascular calcifications (VCs) in 387 hemodialysis patients (mean age 64.2 ± 14.1 years, 63 % males) and in a control group of 51 osteoporotic subjects. Biochemical tests included 25(OH) vitamin D, bone Gla protein (total and undercarboxylated), and total matrix Gla protein. Vertebral quantitative morphometry was carried out centrally for the detection of VF, defined as reduction by ≥20 % of one of the vertebral body dimensions. In the same radiograph, aortic and iliac VC scores were calculated. Prevalence of VF was 55.3 % in hemodialysis patients and 51.0 % in the control group. Multivariate analysis disclosed that male gender (59.8 vs. 47.6 %, p = 0.02; OR = 1.78, 95 % CI 1.15-2.75) and age (mean ± SD 66.7 ± 13.1 vs. 61.0 ± 14.7 years, p < 0.001; OR = 1.03, 95 % CI 1.01-1.05) were significantly associated with VF. The prevalence of aortic VC was significantly higher in hemodialysis patients than in controls (80.6 vs. 68.4 %, p = 0.001). The factors with the strongest association with VC, apart from atrial fibrillation, were serum 25(OH)vitamin D levels below 29 ng/mL for aortic VC (OR = 1.85, 95 % CI 1.04-3.29) and VF both for aortic (OR = 1.77, 95 % CI 1.00-3.14) and iliac (OR = 1.96, 95 % CI 1.27-3.04) VC. In conclusion, the prevalence of VF, especially in males, and VC, in both genders, is high in hemodialysis patients. VF is associated with VC. Vitamin D deficiency is also associated with VC. Further longitudinal studies are warranted to investigate fractures in renal patients.

The relationship between the Spine Deformity Index, biochemical parameters of bone metabolism and vascular calcifications: results from the Epidemiological VERtebral FRACtures iTalian Study (EVERFRACT) in dialysis patients

“…This could be rather surprising considering that VFs are more common in females than in males, at least in the general population [2]. However, we already reported a higher frequency of VFs in hemodialyzed men as compared to women [28]. These results are also consistent with another published report of our group [30] on kidney transplant recipients, demonstrating a higher prevalence of VFs in men.…”

“…Several studies of our and other groups have already demonstrated that VFs are quite common in patients on maintenance HD and associated with vascular calcifications [13,28]. To our knowledge, this is the first study attempting to evaluate the association between the SDI with several factors involved in bone and vascular disease in patients with end-stage renal failure.…”

“…We also determined whether VCs were visible in the iliac arteries calcifications (IAC), creating a score as follows: mild 0.1-3 cm, moderate 3.1-5 cm, and severe > 5 cm, as previously published [28].…”

“…The patient population and the methods of the EVERFRACT study have been already described [28]. Briefly, the EVERFRACT study enrolled 387 adult patients, 244 males and 143 females, aged 64.2 ± 14.1 years, who had been on HD for more than 1 year.…”

“…We have already demonstrated that VFs are associated with several biochemical parameters of skeletal metabolism as well as with atherosclerotic changes in patients on maintenance hemodialysis (HD) [28]. The aim of this study was now to evaluate the relationships between the classic SDI and a c-SDI (developed at our center), laboratory parameters of bone metabolism and vascular calcifications within the context of the EVERFRACT study [28].…”