title: Plasma sodium and subclinical left atrial enlargement in chronic kidney disease.
abstract: BACKGROUND
  Left atrial enlargement (LAE) reflects diastolic dysfunction and predicts mortality in end-stage renal disease patients. However, little is known of its prevalence and factors associated with subclinical LAE in earlier stages of chronic kidney disease (CKD).
  
  
  METHODS
  We conducted a prospective, cross-sectional study in 261 Stage 3-5 non-dialysis CKD patients without symptomatic cardiovascular disease with two-dimensional echocardiography performed to estimate left atrial volume index and other cardiac parameters.
  
  
  RESULTS
  One hundred and nine (41.8%) patients had LAE. Mild and moderate/severe LAEs were observed in 22.9 and 41.3% of patients with left ventricular (LV) hypertrophy (n = 109) versus 13.2 and 12.5% of patients with no LV hypertrophy (n = 152), respectively (P < 0.001). On univariate analysis, plasma sodium concentration showed a significant association with LAE [odds ratio (OR) 1.22, 95% confidence interval (95% CI) 1.09-1.37; P = 0.001]. In the stepwise multiple logistic regression, plasma sodium concentration emerged as one of the most significant factors associated with LAE (adjusted OR 1.29, 95% CI 1.14-1.47; P < 0.001]. Its significance was well maintained (adjusted OR 1.23, 95% CI 1.07-1.43; P = 0.005) when including LV mass and volume index and N-terminal pro-brain natriuretic peptide in the model, while blood haemoglobin and systolic blood pressure were displaced.
  
  
  CONCLUSIONS
  This study for the first time alerted to a very high prevalence of subclinical LAE and reported a strong novel, independent relationship between plasma sodium concentration and subclinical LAE in Stage 3-5 CKD patients. Longitudinal studies are needed to establish causality between high plasma sodium concentration and LAE and their usefulness as therapeutic targets in CKD.
authors: Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong.
authors: Angela
authors: A
authors: Yee-Moon Wang
authors: Ye
authors: Y
authors: Lu
authors: Sharon
authors: S
authors: Cheung
authors: Iris
authors: I
authors: Hiu-Shuen Chan
authors: Christopher
authors: C
authors: Wai-Kei Lam
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000378:metabolism / Q000473:pathology*; D006331:Heart Diseases / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000150:complications*; D012307:Risk Factors; D012964:Sodium / Q000097:blood*; D018608:Ultrasonography, Doppler
chemical_list: D015415:Biomarkers; D012964:Sodium
keywords: chronic kidney disease; echocardiography; left atrial enlargement; plasma sodium