Femoral Neck X-Ray Absorptiometry Parameters and Peripheral Quantitative Computer Tomography Tibial Cortical Density Predict Survival in Dialysis Patients

Nephron. 2017;136(3):183-192. doi: 10.1159/000460262. Epub 2017 Mar 21.

Abstract

Background: Low bone mineral density (BMD) is a known independent predictor of mortality in the general elderly population. However, studies in patients with end-stage renal disease (ESRD) are limited. The present study evaluated mortality during long-term follow-up in a population of patients having dialysis for ESRD, in whom BMD was also measured.

Methods: Fifty-eight patients with ESRD were recruited consecutively from a dialysis clinic and followed prospectively for 6 years. Baseline BMD of the lumbar spine and femoral neck (FN) were measured by X-ray absorptiometry and by peripheral quantitative CT at the radius and tibia. Serum calcium, phosphate, parathyroid hormone (PTH), and albumin were measured at baseline.

Results: During follow-up, 25 patients died. Univariate analysis showed that mortality was significantly associated with FN-BMD: hazards ratio (HR) per 0.1 g/cm2 decrease 1.50 (95% CI 1.07-2.10), p = 0.019; FN-T score: HR per 1-SD decrease 1.84 (95% CI 1.16-2.92), p = 0.009; and tibial cortical density: HR per 10 mg/cm3 decrease 1.08 (95% CI 1.02-1.14), p = 0.010. In multivariate analysis with stepwise adjustment for age, sex, transplant status, albumin, PTH, phosphate, dialysis duration, diabetes, and smoking, FN-T score remained significantly associated with mortality: HR per 1-SD decrease 1.82 (95% CI 1.02-3.24), p = 0.044, whereas the HR for FN-BMD and tibial cortical density were no longer significant. When 4 patients who had peritoneal dialysis were excluded, the HR relating FN-BMD, FN-T score, and tibial cortical density to mortality remained significant but became insignificant when albumin was included in the multivariate analysis.

Conclusion: Reduced FN-BMD, FN-T score, and tibial cortical density were significantly associated with an increased risk of death in patients with ESRD.

Keywords: Bone quantitative computer tomography; Chronic kidney disease-mineral and bone disorder; Dialysis; Mortality; Osteoporosis; X-ray absorptiometry.

MeSH terms

  • Absorptiometry, Photon / methods*
  • Adult
  • Aged
  • Bone Density
  • Female
  • Femur Neck / diagnostic imaging*
  • Humans
  • Kidney Failure, Chronic / diagnostic imaging*
  • Kidney Failure, Chronic / physiopathology
  • Male
  • Middle Aged
  • Renal Dialysis*
  • Survival Analysis
  • Tibia / diagnostic imaging*
  • Tomography, X-Ray Computed / methods*