Survival rate of dialysis patients is still alarmingly low and various factors may have in it an important role. The purpose of this study was to observe the relationship between the survival of dialysis patients and the serum level of urea, creatinine, and uric acid (UA). Serum urea and creatinine concentrations may express patient’s nutritional status and muscle mass, and high UA value may refer to higher risk for cardiovascular events. The idea of combining the concentrations and removal of urea and UA into a single model for predicting the patient’s outcome is introduced. The study included 33 hemodialysis patients from Linköping, Sweden and 10 from Tallinn, Estonia. Kaplan–Meier analysis was used for survival analysis. Logistic and Cox regression analysis was applied to create models for predicting patients’ three-year survival. It was observed that higher serum UA is significantly related to poor survival in dialysis patients (p = 0.026). A reverse effect was observed in case of urea (p = 0.095). The level of creatinine was not related to survival (p = 0.905). The best logistic regression model for predicting patients’ outcome included both UA and urea based parameters (Chi Square 21.0, p = 0.0001). Survival of dialysis patients seems to be determined by a set of causal factors and combined models may have a predictive relevance. A possibility for automatic online monitoring of small molecule uremic markers is proposed. Since the number of participating patients was small, larger studies including more patients and testing the models in independent validation cohort is the future goal.
1. Stokes, J. B. Consequences of frequent hemodialysis: comparison to conventional hemodialysis and transplantation. Trans. Am. Clin. Climatol. Assoc., 2011, 122, 124–136.
2. NKF-KDOQI Guidelines. Clinical practice guidelines for hemodialysis adequacy, update 2006. The National Kidney Foundation Kidney Disease Outcomes Quality Initiative, 2006. http://www.kidney.org/professionals/ KDOQI/guideline_upHD_PD_VA/index.htm
3. Vanholder, R., Glorieux, G., De Smet, R., and Lameire, N. New insights in uremic toxins. Kidney Int., 2003, 63(S84), S6–S10.
http://dx.doi.org/10.1046/j.1523-1755.63.s84.43.x
4. Mitch, W. E. and Ikizler, T. A. Handbook of Nutrition and the Kidney. Lippincott Williams & Wilkins, Philadelphia, 2009.
5. Fouque, D., Vennegoor, M., Ter Wee, P., Wanner, C., Basci, A., Canaud, B. et al. EBPG guideline on nutrition. Nephrol. Dial. Transpl., 2007, 22(suppl 2), ii45–ii87.
http://dx.doi.org/10.1093/ndt/gfm020
6. Yavuz, A., Tetta, C., Ersoy, F. F., D’intini, V., Ratanarat, R., De Cal, M. et al. Reviews: uremic toxins: a new focus on an old subject. Semin. Dialysis, 2005, 18, 203–211.
http://dx.doi.org/10.1111/j.1525-139X.2005.18313.x
7. Basile, C., Vernaglione, L., Lomonte, C., Bellizzi, V., Libutti, P., Teutonico, A. et al. Comparison of alternative methods for scaling dialysis dose. Nephrol. Dial. Transpl., 2010, 25, 1232–1239.
http://dx.doi.org/10.1093/ndt/gfp603
8. Feig, D. I., Kang, D. H., and Johnson, R. J. Uric acid and cardiovascular risk. New Engl. J. Med., 2008, 359, 1811–1821.
http://dx.doi.org/10.1056/NEJMra0800885
9. Høieggen, A., Alderman, M. H., Kjeldsen, S. E., Julius, S., Devereux, R. B., De Faire, U. et al. The impact of serum uric acid on cardiovascular outcomes in the LIFE study. Kidney Int., 2004, 65, 1041–1049.
http://dx.doi.org/10.1111/j.1523-1755.2004.00484.x
10. Viazzi, F., Leoncini, G., Ratto, E., and Pontremoli, R. Serum uric acid as a risk factor for cardiovascular and renal disease: an old controversy revived. J. Clin. Hypertens., 2006, 8, 510–518.
http://dx.doi.org/10.1111/j.1524-6175.2006.04755.x
11. Kanbay, M., Solak, Y., Dogan, E., Lanaspa, M. A., and Covic, A. Uric acid in hypertension and renal disease: the chicken or the egg? Blood Purificat., 2010, 30, 288–295.
http://dx.doi.org/10.1159/000321074
12. Gustafsson, D. and Unwin, R. The pathophysiology of hyperuricaemia and its possible relationship to cardiovascular disease, morbidity and mortality. BMC Nephrol., 2013, 14(164), 9.
13. Heinig, M. and Johnson, R. J. Role of uric acid in hypertension, renal disease, and metabolic syndrome. Clev. Clin. J. Med., 2006, 73, 1059–1064.
http://dx.doi.org/10.3949/ccjm.73.12.1059
14. Madero, M., Sarnak, M. J., Wang, X., Greene, T., Beck, G. J., Kusek, J. W. et al. Uric acid and long-term outcomes in CKD. Am. J. Kidney Dis., 2009, 53, 796–803.
http://dx.doi.org/10.1053/j.ajkd.2008.12.021
15. Hsu, S.-P., Pai, M.-F., Peng, Y.-S., Chiang, C.-K., Ho, T.-I., and Hung, K.-Y. Serum uric acid levels show a ‘J-shaped’ association with all-cause mortality in haemodialysis patients. Nephrol. Dial. Transpl., 2004, 19, 457–462.
http://dx.doi.org/10.1093/ndt/gfg563
16. Suliman, M. E., Johnson, R. J., García-López, E., Qureshi, A. R., Molinaei, H., Carrero, J. J. et al. J-shaped mortality relationship for uric acid in CKD. Am. J. Kidney Dis., 2006, 48, 761–771.
http://dx.doi.org/10.1053/j.ajkd.2006.08.019
17. Latif, W., Karaboyas, A., Tong, L., Winchester, J. F., Arrington, C. J., Pisoni, R. L. et al. Uric acid levels and all-cause and cardiovascular mortality in the hemodialysis population. Clin. J. Am. Soc. Nephrol., 2011, 6, 2470–2477.
http://dx.doi.org/10.2215/CJN.00670111
18. Altman, D. G. Practical Statistics for Medical Research. Chapman & Hall/CRC, 1991.
19. Mankovsky, B., Kurashvili, R., and Sadikot, S. Is serum uric acid a risk factor for atherosclerotic cardiovascular disease? A review of the clinical evidence. Part 1. Diabetes and Metabolic Syndrome: Clinical Research and Reviews, 2010, 4, 176–184.
20. Uhlin, F., Fridolin, I., Lindberg, L. G., and Magnusson, M. Estimating total urea removal and protein catabolic rate by monitoring UV absorbance in spent dialysate. Nephrol. Dial. Transpl., 2005, 20, 2458–2464.
http://dx.doi.org/10.1093/ndt/gfi026
21. Jerotskaja, J., Uhlin, F., Fridolin, I., Lauri, K., Luman, M., and Fernström, A. Optical online monitoring of uric acid removal during dialysis. Blood Purificat., 2009, 29, 69–74.
http://dx.doi.org/10.1159/000264269
22. Holmar, J., Fridolin, I., Uhlin, F., Lauri, K., and Luman, M. Optical method for cardiovascular risk marker uric acid removal assessment during dialysis. Scientific World Journal, 2012; 2012: 8.
23. Tomson, R., Fridolin, I., Uhlin, F., Holmar, J., Lauri, K., and Luman, M. Optical measurement of creatinine in spent dialysate. Clin. Nephrol., 2013, 79, 107–117.
http://dx.doi.org/10.5414/CN107338
http://dx.doi.org/10.1038/ki.2010.218
