Epidemiological study of orthopedic injuries in hemodialysis patients in Taiwan: a fixed cohort survey, 2004-2008

C-type natriuretic peptide attenuates renal osteodystrophy through inhibition of FGF-23/MAPK signaling

Renal osteodystrophy (ROD) occurs as early as chronic kidney disease (CKD) stage 2 and seems ubiquitous in almost all pediatric patients with CKD stage 5. Fibroblast growth factor (FGF)-23, a bone-derived endocrine regulator of phosphate homeostasis, is overexpressed in CKD and disturbs osteoblast differentiation and matrix mineralization. In contrast, C-type natriuretic peptide (CNP) acts as a potent positive regulator of bone growth. In the present study, we infused CNP into uremic rats and observed whether CNP could attenuate ROD through the inhibition of FGF-23 cascades. In uremic rats, CNP administration significantly alleviated renal dysfunction, calcium phosphate metabolic disorders, hypovitaminosis D, secondary hyperparathyroidism, the decrease in bone turnover markers and retarded bone pathological progression. More importantly, within FGF-23/mitogen-activated protein kinase (MAPK) signaling, the fibroblast growth factor receptor-1, Klotho and alternative (STAT-1/phospho-STAT-1) elements were upregulated by CNP, whereas FGF-23, RAF-1/phospho-RAF-1, and downstream (ERK/phospho-ERK and P38/phospho-P38) elements were paradoxically underexpressed in bone tissue. Therefore, CNP exerts a therapeutic effect on ROD through inhibition of FGF-23/MAPK signaling at the RAF-1 level.

Fracture Risk in Dialysis and Kidney Transplanted Patients: A Systematic Review

Chronic kidney disease is associated with an increased risk of fracture and cardiovascular mortality. The risk of fracture in hemodialysis (HD), peritoneal dialysis (PD) and kidney transplant (KT) patients is higher when compared with the general population. However, there exists a knowledge gap concerning which group has the highest risk of fracture. We aimed to compare the risk of fracture in HD, PD, and KT populations. We conducted a systematic review of observational studies evaluating the risk of fracture in HD, PD, or KT patients. Eligible studies were searched using MEDLINE, Embase, Web of Science, and Cochrane Library from their inception to January 2016, and in grey literature. Incidences (cumulative and rate) of fracture were described together using the median, according to fracture sites, the data source (administrative database or cohort and clinical registry), and fracture diagnosis method. Prevalence estimates were described separately. We included 47 studies evaluating the risk of fracture in HD, PD, and KT populations. In administrative database studies, incidence of hip fracture in HD (median 11.45 per 1000 person-years [p-y]), range: 9.3 to 13.6 was higher than in KT (median 2.6 per 1000 p-y; range 1.5 to 3.8) or in PD (median 5.2 per 1000 p-y; range 4.1 to 6.3). In dialysis (HD+PD), three studies reported a higher incidence of hip fracture than in KT. Prevalent vertebral fracture (assessed by X-rays or questionnaire) reported in HD was in a similar range as that reported in KT. Incidence of overall fracture was similar in HD and KT, from administrative databases studies, but lower in HD compared with KT, from cohorts or clinical registry studies. This systematic review suggests an important difference in fracture risk between HD, PD, and KT population, which vary according to the diagnosis method for fracture identification. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Mortality and complications after hip fracture among elderly patients undergoing hemodialysis

BACKGROUND

Osteoporotic hip fractures cause high mortality and morbidity in elderly adults. Compared to the general population, subjects with end-stage renal disease and hemodialysis often develop mineral bone disorders and have a higher risk for hip fractures.

METHODS

We conducted a matched cohort study design and used competing risk analysis to estimate the cumulative incidence of the complication rate. Subjects aged greater than 60 years with hip fracture were selected from Taiwan's National Health Insurance Research Database covering a period from 1997 to 2007, and these subjects were followed up until 2009. We used the Kaplan-Meier method to estimate the overall survival and used the log-rank test and multiple Cox proportional hazards model to explore the risk factors for survival. The cumulative incidence of the first complication was estimated using competing risk analysis.

RESULTS

Among hemodialysis subjects, the three-month, one-year, two-year and five-year mortality rates were 17.3 %, 37.2 %, 51.5 %, and 80.5 %, respectively; the one-year and five-year cumulative incidences of the first surgical complication were 14.2 % and 20.6 %, respectively; and the three-month cumulative incidence of the first medical complication was 24.1 %. Hemodialysis subjects presented a 2.32 times (95 % CI: 2.16-2.49) higher hazard ratio of overall death, 1.15 times (95 % CI: 1.01-1.30) higher sub-hazard ratio (sub-HR) of surgical complications, and 1.35 times (95 % CI: 1.21-1.52) higher sub-HR of the first medical complication than non-hemodialysis controls.

CONCLUSIONS

The overall mortality and complication rates of hemodialysis subjects after surgery for hip fracture were significantly higher than those of non-hemodialysis subjects. Further prospective studies which include important risk factors are necessary to more precisely quantify the adjusted effect of hemodialysis.

Perioperative Implications of End-stage Renal Disease in Orthopaedic Surgery

End-stage renal disease is a prevalent condition that substantially impacts a patient's quality of life. As medical advancements improve function and rates of survival, the number of persons with end-stage renal disease will grow, with orthopaedic surgeons increasingly encountering patients with the disease in their practice. End-stage renal disease is a complex medical condition that is often associated with multiple medical comorbidities. Orthopaedic surgery in patients with this disease is associated with at least a twofold risk of complications and mortality compared with a population without end-stage renal disease. Patients are at an increased risk for cardiovascular, metabolic, hematologic, and infectious complications. Orthopaedic surgeons should be familiar with pertinent issues in the preoperative evaluation and the postoperative management of these patients and should understand the risks of surgery to better inform patients and family. Careful coordination with consulting specialists is necessary to minimize morbidity and improve outcome.