title: Clinical relevance of aortic calcification in urolithiasis patients.
abstract: BACKGROUND
  The aim of the present study is to investigate the clinical relevance of aortic calcification in urolithiasis patients.
  
  
  METHODS
  Between January 2010 and September 2014, 1221 patients with urolithiasis were treated in Oyokyo Kidney Research Institute and Hirosaki University Hospital. Among these, 287 patients (Stone group) on whom adequate data were available were included in this retrospective study. We also selected 148 subjects with early stage (pT1N0M0) renal cell carcinoma from 607 renal cell carcinoma patients who underwent radical nephrectomy at Hirosaki University Hospital (Non-stone group) as control subjects. Validity of the Non-stone group was evaluated by comparison with pair-matched 296 volunteers from 1166 subjects who participated in the Iwaki Health Promotion Project in 2014. Thereafter, age, body mass index, aortic calcification index (ACI), renal function, serum uric acid concentrations, and comorbidities (diabetes, hypertension, or cardiovascular disease) were compared between the Non-stone and Stone groups. Independent factors for higher ACI and impaired renal function were assessed using multivariate logistic regression analysis.
  
  
  RESULTS
  We confirmed relevance of Non-stone group patients as a control subject by comparing the pair-matched community-dwelling volunteers. Backgrounds of patients between the Non-stone and Stone groups were not significantly different except for the presence of hypertension in the Stone group. ACI was not significantly high in the Stone group compared with the Non-stone group. However, age-adjusted ACI was greater in the Stone group than the Non-stone group. Among urolithiasis patients, ACI was significantly higher in uric acid containing stone patients. The number of patients with stage 3B chronic kidney disease (CKD) was significantly higher in the Stone group than in the Non-stone group (12% vs. 4%, P = 0.008). Multivariate logistic regression analysis showed higher aortic calcification index (>13%), and being a stone former were independent factors for stage 3B CKD at the time of diagnosis.
  
  
  CONCLUSIONS
  Aortic calcification and being a stone former had harmful influence on renal function. This study was registered as a clinical trial: UMIN: UMIN000022962.
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan. shingoh@hirosaki-u.ac.jp.
authors.forename: Shingo
authors.identifier: http://orcid.org/0000-0002-0026-4079
authors.initials: S
authors.lastname: Hatakeyama
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Narita
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Itsuto
authors.initials: I
authors.lastname: Hamano
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Matsumoto
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Soma
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tobisawa
authors.affiliation: Department of Advanced Transplant and Regenerative Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Yoneyama
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yoneyama
authors.affiliation: Department of Advanced Transplant and Regenerative Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hashimoto
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Koie
authors.affiliation: Department of Social Medicine, Hirosaki University School of Medicine, Hirosaki, Japan.
authors.forename: Ippei
authors.initials: I
authors.lastname: Takahashi
authors.affiliation: Department of Social Medicine, Hirosaki University School of Medicine, Hirosaki, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Nakaji
authors.affiliation: Department of Urology, Oyokyo Kidney Research Institute, Hirosaki, Japan.
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Terayama
authors.affiliation: Department of Urology, Oyokyo Kidney Research Institute, Hirosaki, Japan.
authors.forename: Tomihisa
authors.initials: T
authors.lastname: Funyu
authors.affiliation: Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.|Department of Advanced Transplant and Regenerative Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Chikara
authors.initials: C
authors.lastname: Ohyama
mesh_terms: D000368:Aged; D001018:Aortic Diseases / Q000150:complications*; D002292:Carcinoma, Renal Cell / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology; D007668:Kidney / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000209:etiology; D007680:Kidney Neoplasms / Q000503:physiopathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D052878:Urolithiasis / Q000150:complications / Q000503:physiopathology*; D061205:Vascular Calcification / Q000150:complications*
keywords: Aortic calcification; Chronic kidney disease; Renal function; Stone former; Urolithiasis