title: Unexpected combined effects of NADH dehydrogenase subunit-2 237 Leu/Met polymorphism and green tea consumption on renal function in male Japanese health check-up examinees: a cross-sectional study.
abstract: BACKGROUND
  NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with longevity in Japanese. A previous study has shown that ND2-237 Leu/Met polymorphism modulates the effects of green tea consumption on risk of hypertension. For men with ND2-237Leu, habitual green tea consumption may reduce the risk of hypertension. Moreover, there is a combined effect of ND2-237 Leu/Met polymorphism and alcohol consumption on risk of mildly decreased estimated glomerular filtration rate (eGFR) (<90 ml/min/1.73 m2). Several beneficial effects of green tea on the kidney have been reported. The objective of this study was to investigate whether ND2-237 Leu/Met polymorphism modifies the effects of green tea consumption on risk of mildly decreased eGFR in male Japanese health check-up examinees.
  
  
  RESULTS
  For ND2-237Leu genotypic men, after adjustment for confounding factors, green tea consumption may increase the risk of mildly decreased eGFR (P for trend = 0.016). The adjusted odds ratio (OR) for mildly decreased eGFR was significantly higher in subjects with ND2-237Leu who consume ≥6 cups of green tea per day than those who consume ≤1 cup of green tea per day (adjusted OR = 5.647, 95% confidence interval: 1.528-20.88, P = 0.009). On the other hand, for ND2-237Met genotypic men, green tea consumption does not appear to determine the risk of mildly decreased eGFR.
  
  
  CONCLUSIONS
  The present results suggest that ND2-237 Leu/Met polymorphism unexpectedly modifies the effects of green tea consumption on eGFR and the risk of mildly decreased eGFR in male Japanese subjects.
authors.affiliation: Department of Public Health, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan. akokaze@med.showa-u.ac.jp.
authors.forename: Akatsuki
authors.initials: A
authors.lastname: Kokaze
authors.forename: Mamoru
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Naomi
authors.initials: N
authors.lastname: Matsunaga
authors.forename: Kanae
authors.initials: K
authors.lastname: Karita
authors.forename: Masao
authors.initials: M
authors.lastname: Yoshida
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Ohtsu
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ochiai
authors.forename: Takako
authors.initials: T
authors.lastname: Shirasawa
authors.forename: Hinako
authors.initials: H
authors.lastname: Nanri
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hoshino
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takashima
mesh_terms: D044466:Asian People / Q000235:genetics*; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005838:Genotype; D005919:Glomerular Filtration Rate; D006801:Humans; D007564:Japan; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D009245:NADH Dehydrogenase / Q000235:genetics*; D016017:Odds Ratio; D010808:Physical Examination; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D013662:Tea
chemical_list: D013662:Tea; D009245:NADH Dehydrogenase; C521326:NADH dehydrogenase subunit 2, human