Increased exposure to aluminum: still a problem for chronic renal failure patients in East China?Increased exposure to aluminum: still a problem for chronic renal failure patients in East China?
Faculty of Medicine and Health Sciences
Trace elements and electrolytes. - München, 1994, currens
27(2010):1, p. 10-19
University of Antwerp
Objective: To evaluate serum aluminum (Al) levels in chronic renal failure (CRF) patients undergoing either conservative or hemodialysis treatment in East China, and check possible relationships with the patients age, sex, dialysis modalities, use of phosphate binders, Epo, VitD, blood transfusion, diet and other trace elements in serum. Patients and methods: The Al concentration was measured in serum samples from 81 CRF patients not yet in dialysis (CRF-NH patients) coming from 5 hospitals of 5 cities, and 319 hemodialysis patients (CRF-H patients) recruited from 8 hospitals of 6 cities in East China. We also measured the Al content in local tap water and dialysate samples from each dialysis center. Serum Al levels in Chinese patients were also compared with those of CRF-H patients from other countries/continents that were available in the lab from previous and ongoing monitoring programs. Al was measured by electrothermal atomic absorption spectrometry. In addition serum samples were also taken from 62 subjects with normal renal function (NRF) which served as controls. Meticulous care was taken to avoid contamination during sampling, storage, shipment and sample analysis. Results: The serum Al content of the CRF patients ranged from 2 µg/l up to 443 µg/l (29.56 ± 44.78 µg/l) and was significantly higher than that of NRF controls (1.77 ± 1.97 µg/l; p < 0.001). Within the CRF group, the serum Al levels of CRF-H patients were significantly higher than those of CRF-NH patients (p < 0.001). Compared with CRF-H patients from European centers in Belgium and Portugal (5.12 ± 6.27 µg/l), serum Al levels of CRF-H patients from East China are significantly higher (p < 0.001) and highly comparable to the overall mean levels of patients from centers in Africa (25.24 ± 29.07 µg/l). Significant differences in serum Al levels were noted between different Chinese dialysis centers under study. These differences could not be explained by the Al content in dialysis fluid (< 2 µg/l) or local tap water. Serum Al levels of CRF-H patients are significantly correlated with age (r = 0.148, p = 0.008), serum calcium (r = 0.224, p = 0.001), and food preference (meat (r = 0.18, p = 0.002), vegetables and fruits (r = 0.201, p = 0.012)). Interestingly, the serum Al level of both CRF-H and CRF-NH patients was significantly influenced by blood transfusions (p < 0.05), Epo treatment (p < 0.001) and VitD administration (p < 0.001), as were the disease duration and serum creatinine level in CRF-NH patients (r = 0.412, p < 0.0001; r = 0.452, p < 0.001, respectively). Conclusion: Al accumulation still exists in CRF patients in East China despite the very low Al levels found in dialysis fluid (< 2 µg/l). In the absence of an adequate renal function, uptake via food or medication seems to be a significant determinant of Al accumulation resulting in higher serum Al levels with age and duration of CRF before entering dialysis.