title: The association of kidney function with repetitive breath-hold diving activities of female divers from Korea, Haenyeo.
abstract: Voluntary apnea during breath-hold diving (BHD) induces cardiovascular changes including bradycardia, reduced cardiac output, and arterial hypertension. Although the impacts of repetitive BHD on cardiovascular health have been studied previously, the long-term risk for kidney dysfunction has never been investigated.
  
  
  
  A cross-sectional propensity score-matched study was performed to evaluate the influence of repetitive long-lasting BHD on kidney function. Using matching propensity scores (PS), 715 breath-hold female divers (Haenyeo) and non-divers were selected for analysis from 1,938 female divers and 3,415 non-divers, respectively. The prevalence of chronic kidney disease (CKD) defined as an estimated glomerular filtration rate (eGFR) calculated to be less than 60 ml/min/1.73 m2was investigated in both diver and non-diver groups.
  
  
  
  The prevalence of CKD was significantly higher in breath-hold divers compared with non-divers after PS matching (12.6% vs. 8.0%, P = 0.004). In multivariate analysis, BHD activity was significantly associated with the risk of CKD in an unmatched cohort (OR, 1.976; 95% CI, 1.465-2.664). In the PS-matched cohort, BHD remained the independent risk factor for CKD even after adjusting for multiple covariates (OR 1.967; 95% CI, 1.341-2.886).
  
  
  
  Shallow but repetitive intermittent apnea by BHD, sustained for a long period of time, may potentially cause a deterioration in kidney function, as a long-term consequence.
authors.affiliation: Department of Internal Medicine, Cheju Halla General Hospital, Doryeong-ro 65, Jeju, 63127, Korea.|Department of Internal Medicine, Gachon University Graduate School of Medicine, Incheon, Korea.
authors.forename: Yun Jung
authors.initials: YJ
authors.lastname: Oh
authors.affiliation: Department of Internal Medicine, Gachon University School of Medicine, Incheon, Korea.|Department of Internal Medicine, Division of Nephrology, Gachon University Gil Medical Center, Incheon, Korea.
authors.forename: Ji Yong
authors.initials: JY
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Cheju Halla General Hospital, Doryeong-ro 65, Jeju, 63127, Korea.
authors.forename: Sung Soo
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Cheju Halla General Hospital, Doryeong-ro 65, Jeju, 63127, Korea.
authors.forename: Kyong-Suk
authors.initials: KS
authors.lastname: Chae
authors.affiliation: Department of Internal Medicine, Cheju Halla General Hospital, Doryeong-ro 65, Jeju, 63127, Korea.
authors.forename: Jiwon
authors.initials: J
authors.lastname: Rhu
authors.affiliation: Department of Internal Medicine, Cheju Halla General Hospital, Doryeong-ro 65, Jeju, 63127, Korea. jaeut@naver.com.
authors.forename: Chungsik
authors.initials: C
authors.lastname: Lee
mesh_terms: D000328:Adult; D062485:Breath Holding; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004242:Diving / Q000706:statistics & numerical data*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D057216:Propensity Score; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology*; D056910:Republic of Korea / Q000453:epidemiology
keywords: Breath-hold diving; Kidney function; Repetitive apnea