Plasma vitamins E and A and risk of bladder cancer: a case-control analysis.
OBJECTIVE
Current results on the association between serum micronutrients and bladder cancer risk have been inconsistent. We assessed plasma vitamin E (alpha-tocopherol, and gamma-tocopherol), vitamin A (retinol), and bladder cancer risk using data collected from a case-control study.


METHODS
Epidemiologic data were collected via in-person interview. Plasma concentrations of alpha-tocopherol, gamma-tocopherol, and retinol were determined by a high-performance liquid chromatography assay. Multivariate logistic regression analyses were used to estimate bladder cancer risk in association with plasma vitamins E and A.


RESULTS
386 bladder cancer patients and 389 age-, gender-, and ethnicity-matched controls were included in the study. The mean plasma alpha-tocopherol and retinol were significantly lower in cases than in controls (alpha-tocopherol: 23.93 microg/ml vs. 27.48 microg/ml, P < 0.001; retinol: 1.41 microg/ml vs. 1.53 microg/ml, P < 0.001). There was a significant reduction in bladder cancer risk associated with increasing plasma alpha-tocopherol level (Adjusted OR: 0.91; 95% CI: 0.85-0.97). In quartile analysis, using subjects with the lowest alpha-tocopherol level as the reference group, the adjusted ORs and 95% CIs for the second, third, and fourth quartiles were 0.75 (0.50-1.14), 0.69 (0.46-1.05), and 0.50 (0.32-0.78), respectively (P for trend = 0.003). Increased retinol level was also associated with reduced risk with OR of 0.57 (95% CI: 0.40-0.81). The ORs and 95% CIs for the second, third, and fourth quartiles were 0.92 (0.61-1.39), 0.66 (0.43-1.01), and 0.62 (0.40-0.95), respectively, with significant dose-response trend (P for trend = 0.01). Finally, there were significant correlations between plasma levels and dietary intakes for the three micronutrients.


CONCLUSIONS
Our results suggest potential protective effect of alpha-tocopherol and retinol on bladder cancer risk. Future large prospective studies are needed to confirm the findings.
Liang
Dong
D
Department of Pharmaceutical Sciences, Texas Southern University, Houston, TX, USA.
Lin
Jie
J
Grossman
H Barton
HB
Ma
Jing
J
Wei
Bo
B
Dinney
Colin P
CP
Wu
Xifeng
X
D000368:Aged; D016022:Case-Control Studies; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012306:Risk; D001749:Urinary Bladder Neoplasms / Q000097:blood*; D014801:Vitamin A / Q000097:blood*; D024502:alpha-Tocopherol / Q000097:blood*; D024504:gamma-Tocopherol / Q000097:blood
D014801:Vitamin A; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol