Sparing effect of peritoneal dialysis vs hemodialysis on BMD changes and its impact on mortality

Differences in prevalence of reduced and low bone mineral density between lumbar spine and femoral neck in peritoneal dialysis patients using dual-energy X-ray absorptiometry (DXA)

The pattern of chronic kidney disease-mineral bone disease has changed following the increase in elderly patients receiving dialysis, with escalating likelihood of osteoporosis, with associated increased fracture risk and mortality. Thus, we wished to determine the prevalence of osteoporosis in our peritoneal dialysis (PD) cohort. Lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), and low BMD (osteoporosis) and reduced BMD (osteopenia) defined according to the World Health Organisation T scores. DXA scans from 734 patients, 57.2% male, mean age 61.0 ±16.0 years, 34.6% diabetic, with a median 8.0 (2-24) months of treatment with PD were reviewed. Fewer patients had normal BMD at the FN vs. LS (24.1 vs. 55%), and more classified as reduced (FN 55.9 vs. 34% LS) and low BMD (FN 17 vs. 11% LS), χ ² 112.2, p < 0.001. Agreement between FN and LS T scores was r = 0.36 with Spearman rank correlation, and 0.34 by Kendall's tau b, Cohen's kappa score 0.17, and Bland-Altman bias -0.37 (95% limits of agreement -1.8 to 1.08). The prevalence of reduced and low BMD was much greater when using FN T scores compared to LS, with LS T scores a mean of 0.34 higher than FN. DXA scanning at the LS can be affected by overlying vascular calcification and electron densities in the bowel, and as such we suggest that FN T scores are used to report BMD in PD patients.

Comparison of CT acquired cardiac valvular calcification scores in hemodialysis and peritoneal dialysis patients undergoing open heart surgery

Study objective

Data is scarce regarding which dialysis modality portends more severe cardiac valvular calcification (CVC). Our aim was to compare the degree of CVC in hemodialysis (HD) and peritoneal dialysis (PD) patient cohorts prior to open heart surgery (OHS) using a CT calcium score.

Design setting and participants

Dialysis patients who underwent OHS at our institution from 2009 to 2019 and who had pre-surgical cardiac CT were included in our study. We obtained duration of dialysis modality prior to their surgical date. There were two study cohorts to evaluate outcomes of interest: mitral and aortic calcification. CVC was assessed using the Agatston score. Logistic regression was performed to test for the association of PD and HD cumulative dialysis duration with presence of CVC.

Results

A total of 214 and 166 patients met inclusion for the mitral and aortic strata, respectively. Age, female sex, and BMI were associated with higher odds of presence of mitral calcification. Age and BMI were associated with higher odds of presence of aortic calcification, while female sex was associated with lower odds in the aortic strata. Cumulative years on PD and cumulative years on HD were not significantly associated with presence of CVC in either cohort.

Conclusion

Presence of mitral and aortic calcification for patients undergoing OHS was not significantly associated with cumulative length of PD or HD after adjusting for age, gender, and BMI suggesting that there may be more factors at play in the progression of CVC in end stage renal disease patients than what was previously established.

Association of Chronic Kidney Disease and Complications Following Acute Torsional Ankle Fracture

BACKGROUND

Although chronic kidney disease (CKD) has been associated with poor outcomes following traumatic fractures, there is a scarcity of literature describing the effect on outcomes of ankle fractures. We will examine the impact of CKD on clinical outcomes following torsional ankle fracture, including complications and unplanned surgical procedures.

METHODS

A retrospective review of 1981 adult patients with torsional ankle fractures treated at a level 1 trauma center was performed to identify patients with CKD based on glomerular filtration rate. Demographic, injury, and treatment-related characteristics were collected. Outcomes included any unplanned procedure: implant removal, debridement, revision, arthrodesis, and amputation; in addition to complications of superficial infection, deep infection, and implant irritation. Patients with CKD were matched with patients without CKD by propensity score matching. Univariate comparisons between groups were conducted using chi-square and Mann-Whitney U tests.

RESULTS

136 patients (68 with CKD and 68 without CKD) were analyzed. Of the 68 patients with CKD, the mean stage of disease was 3.7 with 24% on dialysis for a mean length of 4.1 years. Patients without CKD were more likely to undergo primary ORIF (100% vs 54%, P < .001). Thirty-five percent of patients with CKD had surgical complications vs 19% in the cohort without (P = .07). Patients with open fractures, dislocation, and chronic kidney disease were, respectively, 5.19, 3.77, and 3.91 times more likely to have any complication (P = .02, P = .05, P = .05). Patients with CKD were more likely to undergo unplanned arthrodesis (P = .01). Only dislocation was an independent predictor for unplanned procedure (odds ratio = 5.08, P = .026).

CONCLUSION

Following torsional ankle fracture, CKD is associated with increased likelihood of having a complication or an unplanned arthrodesis. Open fractures and dislocation at time of injury are also associated with complications. Our findings encourage caution about surgical treatment of ankle fractures in patients with CKD.

LEVEL OF EVIDENCE

Level III, retrospective, comparative, prognostic.

Bone Mineral Density Is Inversely Associated With Mortality in Chronic Kidney Disease Patients: A Meta-Analysis

Low bone mineral density (BMD) is suggested to be associated with increased mortality in the general health population, but the relationship in chronic kidney disease (CKD) patients is still unclear. We performed a meta-analysis to investigate the association of BMD in different sites with risk of all-cause mortality in CKD patients. We searched PubMed, EMBASE, and Web of Science to identify eligible cohort studies that evaluated the association between BMD at different sites and risk of all-cause mortality in CKD patients. Twelve cohort studies were identified, which included 2828 CKD patients and 1052 deaths. Compared with normal/high level of total body BMD, lower total body BMD was associated with 25% higher risk of all-cause mortality. The pooled relative risk (RR) was 1.25 (95% confidence interval [CI] 1.09, 1.42) with little heterogeneity across studies. Regarding BMD measured at different sites, the risk of all-cause mortality was highest for lower BMD at hip/femoral neck (pooled RR = 1.69; 95% CI 1.20, 2.40). The pooled RRs were 1.26 (95% CI 1.04, 1.53) and 1.17 (95% CI 1.00, 1.37) for lower BMD at arm and spine, respectively. Similarly, the risk of death for per SD decrease in BMD was also higher at hip/femoral neck (pooled RR = 1.43, 95% CI 1.15, 1.77) compared with arm (pooled RR = 1.03, 95% CI 1.00, 1.06) and spine (pooled RR = 1.17, 95% CI 0.98, 1.39). In conclusion, lower BMD values at hip, arm, spine, as well as the whole body are associated with increased risk of all-cause mortality in CKD patients. The excess risk is highest for patients with lower BMD at hip/femoral neck, suggesting BMD measured at hip region may be the best indicator of mortality risk in CKD patients. © 2022 American Society for Bone and Mineral Research (ASBMR).

Inverse Relationship between Mean Corpuscular Volume and T-Score in Chronic Dialysis Patients

Background and Objectives: Osteoporosis and anemia are prevalent among chronic kidney disease stage 5D (CKD stage 5D) patients. Osteoblasts are known as the niche cells of hematopoietic stem cells (HSCs) and stimulate HSCs to form blood-cell lineages within bone marrow microenvironments. We hypothesized that an inverse correlation may exist between mean corpuscular volume (MCV), a surrogate for ineffective hematopoiesis, and bone mineral density (BMD) in the CKD stage 5D population. Materials and Methods: This is a cross-sectional designed cohort study evaluating CKD stage 5D patients who have received dialysis therapy for over three months. Baseline clinical characteristics and laboratory data were prospectively collected. The dual-energy X-ray absorptiometry (DXA) method was used to measure BMD at five sites, which were bilateral femoral neck, total hip, and lumbar spine 1–4. The Pearson correlation test was initially adopted, and a multivariate linear regression model was further applied for potential confounder adjustments. Results: From September 2020 to January 2021, a total of 123 CKD stage 5D patients were enrolled. The Pearson correlation test revealed a significant inverse association between MCV and BMD at bilateral femoral neck and lumbar spine. The lowest T-score of the five body sites was determined as the recorded T-score. After adjustments for several potential confounding factors, the multivariate linear regression model found consistent negative associations between T-score and MCV. Conclusions: The present study found significant inverse correlations between MCV and BMD at specific body locations in patients on dialysis. A decreased T-score was also found to be associated with macrocytosis after adjustments for confounding variables. However, direct evidence for the causative etiology was lacking.