scholarly journals Biomarkers of Bone Turnover Identify Subsets of Chronic Kidney Disease Patients at Higher Risk for Fracture

2020 ◽  
Vol 105 (8) ◽  
pp. e2903-e2911 ◽  
Author(s):  
Jan M Hughes-Austin ◽  
Ronit Katz ◽  
Richard D Semba ◽  
Stephen B Kritchevsky ◽  
Douglas C Bauer ◽  
...  

Abstract Background We sought to identify biomarkers that indicate low turnover on bone histomorphometry in chronic kidney disease (CKD) patients, and subsequently determined whether this panel identified differential risk for fractures in community-dwelling older adults. Methods Among CKD patients who underwent iliac crest bone biopsies and histomorphometry, we evaluated candidate biomarkers to differentiate low turnover from other bone disease. We applied this biomarker panel to 641 participants in the Health Aging and Body Composition Study (Health ABC) study with estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m2 who were followed for fracture. Cox proportional hazards models evaluated the association of bone mineral density (BMD) with fracture risk and determined whether biomarker-defined low bone turnover modified fracture risk at any level of BMD. Results In 39 CKD patients age 64 ± 13 years, 85% female, with mean eGFR 37 ± 14 mL/min/1.73 m2 who underwent bone biopsy, lower fibroblast growth factor (FGF)-23, higher ɑ-Klotho, and lower parathyroid hormone (PTH) indicated low bone turnover in accordance with bone histomorphometry parameters (individual area under the curve = 0.62, 0.73, and 0.55 respectively; sensitivity = 22%, specificity = 100%). In Health ABC, 641 participants with CKD were age 75 ± 3 years , 49% female, with mean eGFR 48 ± 10 mL/min/1.73 m2. For every SD lower hip BMD at baseline, there was an 8-fold higher fracture risk in individuals with biomarker-defined low turnover (hazard ratio 8.10 [95% CI, 3.40-19.30]) vs a 2-fold higher risk in the remaining individuals (hazard ratio 2.28 [95% CI, 1.69-3.08]) (Pinteraction = .082). Conclusions In CKD patients who underwent bone biopsy, lower FGF-23, higher ɑ-Klotho, and lower PTH together had high specificity for identifying low bone turnover. When applied to older individuals with CKD, BMD was more strongly associated with fracture risk in those with biomarker-defined low turnover.

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4402
Author(s):  
Mathias Haarhaus ◽  
Anders Fernström ◽  
Abdul Rashid Qureshi ◽  
Per Magnusson

Circulating alkaline phosphatase (ALP) is an independent cardiovascular risk marker. Serum bone ALP (BALP) isoforms indicate bone turnover and comprise approximately 50% of total circulating ALP. In chronic kidney disease (CKD), mortality is highest in patients with increased ALP and BALP and low bone turnover. However, not all low bone turnover states are associated with increased mortality. Chronic inflammation and oxidative stress, features of protein energy wasting syndrome, induce cardiovascular BALP activity and fibro-calcification, while bone turnover is suppressed. Circulating BALP isoform B1x is associated with low ALP and low bone turnover and has been exclusively detected in CKD. We investigated the association of serum B1x with survival, abdominal aortic calcification (AAC) score, and aortic pulse wave velocity (PWV) in CKD. Serum ALP, BALP isoforms, parathyroid hormone (PTH), PWV, and AAC were measured repeatedly over 2 years in 68 prevalent dialysis patients. Mortality was assessed after 5 years. B1x was detected in 53 patients. A competing risk analysis revealed an association of B1x with improved 5-year survival; whereas, baseline PWV, but not AAC score, predicted mortality. However, PWV improved in 26 patients (53%), and B1x was associated with variation of PWV over time (p = 0.03). Patients with B1x had lower PTH and total ALP, suggesting an association with lower bone turnover. In conclusion, B1x is associated with time-varying PWV, lower circulating ALP, and improved survival in CKD, and thus may be an indicator of a reduced cardiovascular risk profile among patients with low bone turnover.


Medicina ◽  
2020 ◽  
Vol 57 (1) ◽  
pp. 15
Author(s):  
Altynay Balmukhanova ◽  
Kairat Kabulbayev ◽  
Harika Alpay ◽  
Assiya Kanatbayeva ◽  
Aigul Balmukhanova

Background and objectives: Chronic kidney disease (CKD) in children is a complex medical and social issue around the world. One of the serious complications is mineral-bone disorder (CKD-MBD) which might determine the prognosis of patients and their quality of life. Fibroblast growth factor 23 (FGF-23) is a phosphaturic hormone which is involved in the pathogenesis of CKD-MBD. The purpose of the study was to determine what comes first in children with CKD: FGF-23 or phosphate. Materials and Methods: This cross-sectional study included 73 children aged 2–18 years with CKD stages 1–5. We measured FGF-23 and other bone markers in blood samples and studied their associations. Results: Early elevations of FGF-23 were identified in children with CKD stage 2 compared with stage 1 (1.6 (1.5–1.8) pmol/L versus 0.65 (0.22–1.08), p = 0.029). There were significant differences between the advanced stages of the disease. FGF-23 correlated with PTH (r = 0.807, p = 0.000) and phosphate (r = 0.473, p = 0.000). Our study revealed that the elevated level of FGF-23 went ahead hyperphosphatemia and elevated PTH. Thus, more than 50% of children with CKD stage 2 had the elevating level of serum FGF-23, and that index became increasing with the disease progression and it achieved 100% at the dialysis stage. The serum phosphate increased more slowly and only 70.6% of children with CKD stage 5 had the increased values. The PTH increase was more dynamic. Conclusions: FGF-23 is an essential biomarker, elevates long before other markers of bone metabolism (phosphate), and might represent a clinical course of disease.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Trisha Sachan ◽  
Anita Saxena ◽  
Amit Gupta

Abstract Background and Aims Changes in dietary phosphorus regulate serum FGF-23, parathyroid hormone, 1,25(OH)(2)D and Klotho concentrations . Cardiovascular disease (CVD) is the principal killer of patients with chronic kidney disease and hyperphosphetemia is a potent risk factor it. Of many causative factors for CVD in CKD, dietary interventions involving restriction of dietary phosphorous intake can help reduce onset of CVD at early stages of CKD with other corrective measures. Muscle wasting is a consequence of uremic syndrome which alters body composition. The aim of the study was to study effect of dietary phosphorous restriction on FGF-23, iPTH, Klotho, 1,25(OH)(2)D and body composition in chronic kidney disease patients. Method This is a longitudinal study with 12 months intervention, approved by Ethics Committee of the institute. A total 132 subjects were recruited (66 healthy controls, 66 CKD patient. of 66 patients 33 were in CKD stage 1 and 33 in stage 2. GFR was calculated with the help of MDRD formula. Biochemical parameters of subjects were evaluated at baseline, 6 and 12 months along with the anthropometric measurements (body weight, height, mid upper arm circumference (MUAC), and skin folds). Three days dietary recall was taken to evaluate energy, protein and phosphorous intake. CKD patients whose dietary phosphorous intake was more than 1000 mg/day, were given intense dietary counseling and prescribed dietary modifications by restricting dietary phosphorous between 800-1000 mg/day. Results The mean age of controls and patients was 37.01±9.62 and 38.27±12.06 and eGFR of 136.94±11.77 and 83.69±17.37 respectively. One way ANOVA showed significant difference among controls and the study groups in hemoglobin (p<0.001), s albumin (p<0.001), FGF-23 (p<0.001), klotho (p<0.001), urinary protein (p<0.001) and Nephron Index (p<0.001).The mean energy intake (p = 0.001) and dietary phosphorous intake (p<0.001) of the CKD patients decreased significantly with the decline in the renal function along with the anthropometric measures i.e. BMI (p = 0.041),WHR (p = 0.015) and all four skin folds (p<0.001). On applying Pearson’s correlation, eGFR correlated negatively with urinary protein (-0.739, 0.000), FGF-23 (-0.679, 0.000) and serum phosphorous (-0.697, 0.000) and positively with klotho (0.872, 0.000). FGF-23 correlated negatively with klotho (-0.742, 0.000). Dietary phosphorous was found to be positively correlated with urinary protein (0.496, 0.000), serum phosphorous (0.680, 0.000) and FGF-23 (0.573, 0.000) and negatively with Klotho (-0.602, 0.000). Nephron index revealed a positive correlation with eGFR (0.529, 0.000). Urinary protein correlated negatively with klotho (-0.810, 0.000). A multiple linear regression was run to predict eGFR from anthropometric variables such as BMI, WHR, MUAC, skin folds thickness and handgrip strength. All anthropometric variables predicted decline in eGFR (p<0.05, R2 =0.223). At 6 and 12 months; repeated ANOVAs analysis showed a statistically significant difference in serum creatinine (p=0.000), serum phosphorous (p=0.000), FGF-23(p=0.000) and klotho (p=0.000). Conclusion Elevated levels of FGF-23 and decreased Klotho levels, with the moderate decline in renal function improved with the restricted phosphorous diet at 6 and 12 months emphasizing the importance of phosphorus restriction at an early stage.


Bone ◽  
2009 ◽  
Vol 45 ◽  
pp. S63-S64
Author(s):  
H. Ziolkowska ◽  
M. Panczyk-Tomaszewska ◽  
A. Debinski ◽  
M. Roszkowska-laim

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