title: Body Mass Index Modifies an Association between Self-Reported Regular Exercise and Proteinuria.
abstract: OBJECTIVE
  Regular exercise habits are well-known to exert a favorable effect on the metabolic syndrome, which may cause proteinuria and chronic kidney disease (CKD). However, it remains unknown if exercise exerts a favorable effect on proteinuria and kidney dysfunction. The aim of this study was to reveal the association between exercise and the prevalence of proteinuria and kidney dysfunction and the attenuation by obesity.
  
  
  METHODS
  This study was a cross-sectional cohort study that included 292,013 participants who underwent the Specific Health Check and Guidance in Japan. The exercise score (range 0-3) was based on the number of positive answers to three questions regarding exercise habits. The outcome was defined as urinary protein detected by a dipstick test and kidney dysfunction [estimated glomerular filtration rate (GFR) less than 45 ml/min/1.73 m(2)].
  
  
  RESULTS
  The exercise score was significantly associated with the prevalence of proteinuria in both males [vs. exercise score 0; exercise score 1, multivariate-adjusted odds ratio 0.86 (95% confidence interval 0.81-0.92), P<0.001; exercise score 2, 0.84 (0.79-0.90), P<0.001; exercise score 3, 0.77 (0.72-0.82), P<0.001] and females (same as in males). After the male subjects were divided into quintiles according to body mass index (BMI) in more than three groups (22.9<BMI<24.1), there was no significant association between the exercise score and the prevalence of proteinuria. In females, a higher exercise score was associated with a lower prevalence of proteinuria, regardless of BMI. The association between the exercise score and kidney dysfunction was as similar as that between the exercise score and proteinuria, except the attenuation of BMI.
  
  
  CONCLUSIONS
  Exercise may associate with a lower prevalence of proteinuria and kidney dysfunction, and a high BMI may attenuate this association between exercise and proteinuria in male subjects.
authors.affiliation: Department of Internal Medicine, Division of Kidney and Dialysis, Hyogo College of Medicine.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Nagasawa
authors.forename: Ryohei
authors.initials: R
authors.lastname: Yamamoto
authors.forename: Maki
authors.initials: M
authors.lastname: Shinzawa
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Hasuike
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kuragano
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Isaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Iseki
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yamagata
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tsuruya
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yoshida
authors.forename: Shouichi
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Koichi
authors.initials: K
authors.lastname: Asahi
authors.forename: Toshiki
authors.initials: T
authors.lastname: Moriyama
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007564:Japan; D007674:Kidney Diseases / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D015995:Prevalence; D011507:Proteinuria / Q000175:diagnosis* / Q000453:epidemiology; D057566:Self Report; D012737:Sex Factors; D011795:Surveys and Questionnaires