title: Hyponatremia Predicts New-Onset Cardiovascular Events in Peritoneal Dialysis Patients.
abstract: OBJECTIVE
  Cardiovascular (CV) disease is the leading cause of morbidity and mortality in patients on peritoneal dialysis (PD). Hyponatremia was recently shown to be a modifiable factor that is strongly associated with increased mortality in PD patients. However, the clinical impact of hyponatremia on CV outcomes in these patients is unclear.
  
  
  METHODS
  To determine whether a low serum sodium level predicts the development of CV disease, we carried out a prospective observational study of 441 incident patients who started PD between January 2000 and December 2005. Time-averaged serum sodium (TA-Na) levels were determined to investigate the ability of hyponatremia to predict newly developed CV events in these patients.
  
  
  RESULTS
  During a mean follow-up of 43.2 months, 106 (24.0%) patients developed new CV events. The cumulative incidence of new-onset CV events after the initiation of PD was significantly higher in patients with TA-Na levels ≤ 138 mEq/L than in those with a TA-Na > 138 mEq/L. After adjustment for multiple potentially confounding covariates, an increase in TA-Na level was found to be associated with a significantly lower risk of CV events (subdistribution hazard ratio per 1 mEq/L increase, 0.90; 95% confidence interval, 0.83-0.96; p = 0.003). Patients with a TA-Na ≤ 138 mEq/L had a 2.31-fold higher risk of suffering a CV event.
  
  
  CONCLUSIONS
  These results provide evidence of a clear association between low serum sodium and new-onset CV events after dialysis initiation in PD patients. Whether the correction of hyponatremia for this indication provides additional protection for the development of CV disease in these patients remains to be addressed in interventional studies.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hyung Woo
authors.initials: HW
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Geun Woo
authors.initials: GW
authors.lastname: Ryu
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Cheol Ho
authors.initials: CH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, NHIS Medical Center, Ilsan Hospital, Goyangshi, Gyeonggi-do, Republic of Korea.
authors.forename: Ea Wha
authors.initials: EW
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jung Tak
authors.initials: JT
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Hyeok
authors.initials: SH
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, NHIS Medical Center, Ilsan Hospital, Goyangshi, Gyeonggi-do, Republic of Korea.
authors.forename: Sug Kyun
authors.initials: SK
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; Brain Korea 21 for Medical Science, Severance Biomedical Science Institute, Yonsei University, Seoul, Republic of Korea.
authors.forename: Shin-Wook
authors.initials: SW
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyu Hun
authors.initials: KH
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Dae Suk
authors.initials: DS
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, NHIS Medical Center, Ilsan Hospital, Goyangshi, Gyeonggi-do, Republic of Korea.
authors.forename: Tae Ik
authors.initials: TI
authors.lastname: Chang
mesh_terms: D002318:Cardiovascular Diseases / Q000209:etiology*; D006801:Humans; D007010:Hyponatremia / Q000150:complications*; D015994:Incidence; D015999:Multivariate Analysis; D010530:Peritoneal Dialysis; D016016:Proportional Hazards Models; D012307:Risk Factors