Clinical predictors of incipient vertebral fractures and bone mineral
density in kidney transplant patients
Abstract
Purpose: Kidney transplant recipients are prone to metabolic bone
diseases and consequent fractures. This study aimed to evaluate the
incidence of incipient vertebral fractures, osteopenia, osteoporosis,
and the clinical factors associated with incipient vertebral fractures
in a group of kidney transplant patients. Methods: Two hundred
sixty-four patients (F/M:124/140, 45.3±13 years) who had undergone
kidney transplantation between 2008 and 2018 and who were followed up at
least one year in third care centers were included in this multicenter
retrospective study. Bone mineral densitometry was performed using
dual-energy X-ray absorptiometry. Vertebral fractures were assessed
semi-quantitatively using conventional thoracolumbar lateral radiography
in 202 of the patients. Results: Vertebral fractures were observed in
56.4% (n=114) of the study group. Severe vertebral fractures were
observed in 30.7% (n=62) of the patients in vertebral X-ray evaluation.
The frequency of osteoporosis was 20.0% (53 of 264 patients), and
osteopenia was 35.6% (94 of 264 patients). BMD levels were in the
normal range in 40.3% (n=46) of the subjects with vertebral fractures.
It was in the osteoporotic range in 20.1% (n=23) and the osteopenic
range in 40.3% (n=46). Serum calcium, parathormone vitamin, and
creatinine levels were similar between the patients with and without
vertebral fractures. Femoral neck BMD was negatively correlated with age
(r: −0.21, p<0.001) and positively correlated with body mass
index (r:0.29, p<0.001). Vertebral fractures were associated
with age, duration of hemodialysis, BMI, femoral neck Z score (R2:
37.8%, p=0.027). Conclusion: BMD was in the normal or osteopenic range
in 79.8% in our cohort of renal transplant patients with incipient
vertebral fractures. As incipient vertebral fractures can be observed in
patients with normal BMD levels in kidney transplant recipients,
conventional X-ray screening for vertebral fractures may be beneficial
for a proper therapy decision of metabolic bone disease in kidney
transplant recipients.