Serum antioxidant micronutrients and the risk of oral leukoplakia among Japanese.
A population-based case-control study was designed for the investigation of any association between serum micronutrient levels and oral leukoplakia. Out of a total of 9536 subjects over the age of 40 years who participated in the oral mucosal screening programme in Tokoname city, 48 cases detected with oral leukoplakia (38 male:10 female) were recruited. For each case, four controls matched by age and sex were selected from the same cohort. We examined the fasting serum levels of retinol, alpha-tocopherol, zeaxanthin and lutein, cryptoxanthin, lycopene and carotenoids (alpha-carotene and beta-carotene) by high-performance liquid chromatography. Among males with leukoplakia mean serum lycopene and beta-carotene levels (0.175+/-0.202, 0.357+/-0.295 micromol/l) were significantly lower than those of controls (0.257+/-0.252, 0.555+/-0.408 micromol/l) (P<0.05, P<0.005). Logistic regression analysis with leukoplakia as the dependent variable showed that high serum levels of beta-carotene were related to low risk of oral leukoplakia (odds ratio 0.160, 95% C.I.: 0.029-0.866, P<0.05). There were no significant differences in any of the serum nutrients estimated in female subjects. Our results suggest for the first time that high serum levels of beta-carotene may provide protection against oral precancer for the Japanese male.
Nagao
T
T
Second Department of Oral and Maxillofacial Surgery, School of Dentistry, Aichi-Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya, Japan. tnagao@dpc.aichi-gakuin.ac.jp
Ikeda
N
N
Warnakulasuriya
S
S
Fukano
H
H
Yuasa
H
H
Yano
M
M
Miyazaki
H
H
Ito
Y
Y
D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000627:therapeutic use; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007564:Japan; D007972:Leukoplakia, Oral / Q000097:blood*; D016015:Logistic Models; D008297:Male; D009062:Mouth Neoplasms / Q000097:blood*; D012907:Smoking / Q000009:adverse effects; D014801:Vitamin A / Q000097:blood* / Q000627:therapeutic use; D014810:Vitamin E / Q000097:blood* / Q000627:therapeutic use; D019207:beta Carotene / Q000097:blood* / Q000627:therapeutic use
D000975:Antioxidants; D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E