title: Low-normal serum potassium is associated with an increased risk of cardiovascular and all-cause death in community-based elderly.
abstract: OBJECTIVE
  Several studies have already reported that serum potassium (SK) correlated inversely with adverse events among patients with preexisting cardiovascular disease and impaired renal function; less is known about the prognostic value of SK at the normal range in community-based elderly individuals. This study aimed to examine whether low normal SK value was associated with cardiovascular and all-cause mortalities in elderly people.
  
  
  METHODS
  A prospective study was conducted using two independent elderly Taiwanese community cohorts that included 2065 individuals with relatively normal SK values (2.8-5.6 mmol/L). The participants were grouped as follows: low (2.8-3.4 mmol/L), low-normal SK (3.5-3.8 mmol/L), normal (3.9-4.4 mmol/L), and high-normal SK (4.5-5.6 mmol/L). Proportional hazards model was applied to compare the association between SK concentration groups and mortality.
  
  
  RESULTS
  The relationship between baseline SK and all-cause and cardiovascular mortality was U-shaped, with the lowest mortality rates observed in patients with SK levels of 3.9-4.4 mmol/L. The low-normal SK group had significantly higher risks of all-cause (hazard ratio, 1.3; 95% confidence interval, 1.0-1.6) and cardiovascular mortality (hazard ratio, 1.6; 95% confidence interval, 1.1-2.3) than the normal SK group. The high-normal SK group had higher but nonsignificant risk compared to the normal group.
  
  
  CONCLUSIONS
  Our findings suggest that low-normal SK may be used as a marker of poor survival for elderly outpatient cares.
authors.affiliation: Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, Taiwan.
authors.forename: Ying-Ho
authors.initials: YH
authors.lastname: Lai
authors.affiliation: Healthcare and Management Center, Division of Cardiology, Department of Internal Medicine, Taipei Veterans General Hospital, Number 201, Section 2, Shih-Pai Road, Taipei, Taiwan.
authors.forename: Hsin-Bang
authors.initials: HB
authors.lastname: Leu
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Number 128, Section 2, Academia Road, Taipei, Taiwan.
authors.forename: Wen-Ting
authors.initials: WT
authors.lastname: Yeh
authors.affiliation: Division of Preventive Medicine and Health Services Research, Institute of Population Health Sciences, National Health Research Institutes, Number 35, Keyan Road, Miaoli, Taiwan.
authors.forename: Hsing-Yi
authors.initials: HY
authors.lastname: Chang
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Number 128, Section 2, Academia Road, Taipei, Taiwan. Electronic address: pan@ibms.sinica.edu.tw.
authors.forename: Wen-Harn
authors.initials: WH
authors.lastname: Pan
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000401:mortality*; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007008:Hypokalemia / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D009026:Mortality; D015999:Multivariate Analysis; D011188:Potassium / Q000097:blood*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D011188:Potassium
keywords: cardiovascular mortality; elderly; serum potassium