Plasma sodium and subclinical left atrial enlargement in chronic kidney disease

Nephrol Dial Transplant. 2013 Sep;28(9):2319-28. doi: 10.1093/ndt/gfs588. Epub 2013 Jan 12.

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.

Keywords: chronic kidney disease; echocardiography; left atrial enlargement; plasma sodium.

MeSH terms

  • Biomarkers / metabolism
  • Cross-Sectional Studies
  • Echocardiography
  • Female
  • Follow-Up Studies
  • Heart Atria / metabolism
  • Heart Atria / pathology*
  • Heart Diseases / blood
  • Heart Diseases / diagnosis*
  • Heart Diseases / etiology
  • Humans
  • Male
  • Middle Aged
  • Prognosis
  • Prospective Studies
  • Renal Insufficiency, Chronic / complications*
  • Risk Factors
  • Sodium / blood*
  • Ultrasonography, Doppler

Substances

  • Biomarkers
  • Sodium