Reply to CK Chow

摘要

We thank Dr Chow for his comments on our study (1). Several methods have been suggested and used to adjust serum vitamin E status for serum lipids (2), but the issue has not been standardized. In preliminary analyses, we tested several possible approaches—the ratios of vitamin E to cholesterol, to tryglicerides, or to cholesterol plus tryglicerides—but the results did not differ significantly. Therefore, we chose the adjustment that made it easier to compare our data with the data of the studies we referenced. The fact that significant associations were found only after adjustment for cholesterol values was clearly pointed out in the discussion as a major limitation of the study. However, the plasma concentration of vitamin E varies with the amount of concurrent lipids, and lipid standardization is needed to estimate the biological status of vitamin E (3).