title: Multiple linear regression analysis of the seasonal changes in the serum concentration of beta-cryptoxanthin.
abstract: Beta-cryptoxanthin (beta-CRX) is a carotenoid pigment found in Satsuma mandarin (Citrus unshiu Marc.) fruit, which is heavily produced in Japan. In this study, we evaluated the seasonal changes in the serum beta-CRX level and investigated predictors of serum beta-CRX level by multiple linear regression analysis. Blood tests and self-administered questionnaires were used every other month for one year. The subjects were healthy volunteers, 15 males and 12 females. The serum beta-CRX levels increased dramatically as the intake of Satsuma mandarin increased; the maximum increase was noted in January. Multiple linear regression analysis showed that, in males, the serum beta-CRX level could be predicted by Satsuma mandarin intake, age and the month of blood sampling; however, it was inversely associated with alcohol and smoking habits. Conversely, in females, the serum beta-CRX concentration could be predicted by Satsuma mandarin intake, the month of blood sampling and age; however, it was inversely associated with body mass index. The results of multiple linear regression analysis suggest that the serum beta-CRX levels can be used to evaluate the intake volume of Satsuma mandarin. Furthermore, beta-CRX is a useful biomarker to estimate the beneficial effects of Satsuma mandarin intake in epidemiological studies.
authors.affiliation: Department of Citrus Research, National Institute of Fruit Tree Science, 485-6 Shimizu-Okitsunakachou, Shizuoka-shi, Shizuoka 424-0292, Japan. msugiura@affrc.go.jp
authors.forename: Minoru
authors.initials: M
authors.lastname: Sugiura
authors.forename: Hikaru
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Masaya
authors.initials: M
authors.lastname: Kato
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ikoma
authors.forename: Masamichi
authors.initials: M
authors.lastname: Yano
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nagao
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking; D015992:Body Mass Index; D002957:Citrus / Q000737:chemistry; D065366:Cryptoxanthins; D004032:Diet; D005260:Female; D005638:Fruit / Q000737:chemistry; D006801:Humans; D007564:Japan; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012621:Seasons; D012907:Smoking; D024341:Xanthophylls; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000097:blood*
chemical_list: D065366:Cryptoxanthins; D024341:Xanthophylls; D019207:beta Carotene