Incidence of chronic kidney disease in India.

istics between the two groups (Table 1). Antioxidant supplementation with vitamin C and vitamin E resulted in significant changes in plasma concentrations of vitamin C (40±48 vs 19±33 mmol/l for placebo, P<0.001) as well as vitamin E (25±15 vs 1±10 mmol/l for placebo, P<0.001). CsA trough-levels decreased in the treatment group compared with the placebo group ( 14±25 vs 10±30mg/l, P1⁄4 0.003), as did the serum creatinine concentration (resp, 6±17 and 4±15mmol/l, P1⁄4 0.035). Neither changes in vitamin C nor changes in vitamin E concentrations were correlated with changes in CsA trough-levels or changes in serum creatinine concentrations in the treatment group. A borderline significant correlation was found between changes in CsA troughlevels and changes in serum creatinine concentrations (r1⁄4 0.36, P1⁄4 0.07). The results of our study confirm the finding by Blackhall et al. [1] that antioxidant supplementation reduces CsA trough-levels in renal transplant recipients. Injudicious use of vitamin C and E supplementation should therefore be avoided, until it has been documented that the decreased CsA levels associated with their use pose no risk for transplant rejection. Blackhall et al. [1] also found a significant decrease in serum creatinine concentrations. Our results confirm this finding as well. Blackhall et al. [1] supplemented b-carotene in addition to vitamin E and vitamin C, whereas our study only supplemented the latter two anti-oxidants. It is therefore unlikely that b-carotene in the study of Blackhall was responsible for either the changes in CsA trough-levels or the changes in serum creatinine concentrations. In conclusion, we concur with Blackhall et al. [1] that transplant nephrologists should be aware of the CsA troughlevel lowering effect of anti-oxidants.