Growth differentiation factor GDF-15 does not influence iron metabolism in stable chronic haemodialysis patients

GDF-15 and hepcidin as a therapeutic target for anemia in chronic kidney disease

BACKGROUND

Anaemia is a common presenting feature among patients with chronic kidney disease (CKD) and associated with poor clinical outcomes. We evaluated the diagnostic validity of growth differentiation factor-15 (GDF-15) and hepcidin as it is not clear if they are useful as a biomarkers of anaemia among non-dialysis CKD egyptian patients.

METHOD

An analytical cross-sectional study was conducted among non-dialysis CKD patients (n = 60) and apparently healthy controls (n = 28) at Minia University maternity & children Hospital. Serum levels of GDF-15 and hepcidin were determined. Predictive logistic regression models were built and post estimation receiver operator characteristics were determined to evaluate diagnostic validity of hepcidin and GDF-15 for iron deficiency anaemia.

RESULTS

Hepcidin and GDF-15 are significantly higher in cases than control p value (0.047 < 0.0001) respectively. The predictive value of diagnosing anaemia among CKD patients using hepcidin and GDF-15 was 72.0%, 70.0%. There was a weak negative correlation between hepcidin levels and glomerular filtration rate GFR (r = -.175, p = 0.105) in CKD patients, and significant correlation between serum GDF-15 and haemoglobin (r = -0.897, p < 0.0001), ferritin (r = 0.489, P < 0.000), Iron (r = -0.314, P = 0.002), CRP (r = 0.409, P < 0.0001).

CONCLUSION

Hepcidin and GDF-15 is a potential biomarker for predicting anaemia connected with inflammation among CKD Egyptian patients.

Hepcidin and GDF-15 are potential biomarkers of iron deficiency anaemia in chronic kidney disease patients in South Africa

BACKGROUND

Anaemia is a common presenting feature among patients with chronic kidney disease (CKD) and it is associated with poor clinical outcomes and quality of life. It is not clear if growth differentiation factor-15 (GDF-15) or hepcidin are useful as early markers of iron deficiency anaemia (IDA) among non-dialysis CKD patients. We therefore evaluated the diagnostic validity of GDF-15 and hepcidin as biomarkers of IDA among non-dialysis CKD patients in Johannesburg, South Africa.

METHOD

An analytic cross-sectional study was conducted among non-dialysis CKD patients (n = 312) and apparently healthy controls (n = 184) from June to December 2016 at an Academic Hospital, in Johannesburg, South Africa. An interviewer administered proforma was used to obtain the socio-biological and clinical characteristics of the participants. Serum levels of GDF-15 and hepcidin were determined. Predictive logistic regression models were built and post estimation receiver operator characteristics were determined to evaluate diagnostic validity of hepcidin and GDF-15 for absolute and functional iron deficiency anaemia.

RESULTS

About half (50.6%) of the participants were female while the participants' mean age was 49.7 ± 15.8 years. The predictive value of diagnosing absolute IDA among CKD patients using GDF-15 was 74.02% (95% CI: 67.62-80.42%) while the predictive value of diagnosing functional IDA among CKD patients using hepcidin was 70.1% (95% CI: 62.79-77.49%).There was a weak negative correlation between hepcidin levels and GFR (r = - 0.19, p = 0.04) in anaemic CKD patients, and between serum GDF-15 and haemoglobin (r = - 0.34, p = 0.001). Serum ferritin (β = 0.00389, P-value< 0.001), was a predictor of log hepcidin. MCHC (β = - 0.0220, P-value 0.005) and CKD stage (β = 0.4761, P-value < 0.001), race (β = 0.3429, P-value = 0.018) were predictors of log GDF-15. Both GDF-15 (adj OR: 1.0003, 95%CI: 1.0001-1.0005, P = 0.017) and hepcidin (adj OR: 1.003, 95%CI: 1.0004-1.0055, P = 0.023) were associated with iron deficiency anaemia after multiple linear regression modelling.

CONCLUSION

Serum GDF-15 is a potential biomarker of absolute IDA, while hepcidin levels can predict functional IDA among CKD patients.

GDF-15, iron, and inflammation in early chronic kidney disease among elderly patients

PURPOSE

The aim of the study was to assess GDF-15 and iron status in patients in early stages of chronic kidney disease with a particular emphasis on elderly population in association of classic iron status parameters with novel iron homeostasis biomarkers and inflammatory parameters.

METHODS

Serum concentrations of GDF-15, iron (Fe), transferrin saturation, soluble transferrin receptor (sTfR), hepcidin, high-sensitive C-reactive protein (hsCRP), interleukin 6 (IL-6), and hemoglobin were measured in 56 patients ≥65 years of age and in 31 <65 years of age.

RESULTS

In patients ≥65 years, serum concentrations of GDF-15 and hsCRP were significantly higher in comparison with younger group. There was no statistically significant difference in hemoglobin, iron, hepcidin, and sTfR concentration between the two studied groups. In both groups GDF-15 was significantly correlated with hemoglobin, eGFR, hsCRP, and IL-6. GDF-15 was significantly higher in patients with anemia in comparison with their non-anemic counterparts. In multivariate analysis, hemoglobin was found to be a predictor of log GDF-15 (beta value = 0.36, P = 0.006, R (2) = 37 %).

CONCLUSIONS

An intricate interplay between renal function, anemia, and GDF-15 concentrations awaits further studies, as there are few data regarding pathophysiological role of GDF-15 in diabetes, kidney disease, and other comorbidities. Further understanding regarding the signaling pathways of GDF-15 may help to discover next pieces in the exciting puzzle of GDF-15. Finally, as studies dealing with normal level of GDF-15 in the healthy aged are lacking, it is possible that the higher values of GDF-15 values found in the present study represent values of GDF-15 according to age more than CKD levels.