High sodium intake may impair cardiac structure, function
Estimated sodium intake (ESI) greater than 3.7 g per day may result in adverse cardiac remodeling and worse systolic strain and diastolic e’ velocity, according to a study.
Researchers conducted speckle-tracking analysis on Hyper Genetic Epidemiology Network (HyperGEN) study echocardiograms with available urinary sodium data (n=2,996) to examine whether assessment of left ventricular longitudinal strain (LS), circumferential strain and e’ velocity could provide insight into thresholds for the detrimental effects of ESI on subclinical cardiovascular disease.
The associations among ESI and LS, circumferential strain and e’ velocity was evaluated using multivariable-adjusted linear mixed-effects models with linear splines (spline 1: ESI ≤3.7 g/day; spline 2: ESI >3.7 g/day based on visual inspection of fractional polynomial plots of the association between ESI and indices of strain and e′ velocity).
Researchers also sought to understand the indirect effects of systolic blood pressure (SBP) and serum aldosterone on the relationship between ESI and strain and e’ velocity by performing mediation analysis.
Participants (mean age 49 years; 57 percent female; 50 percent African American; 54 percent had hypertension) had a median ESI of 3.73 g/day. ESI >3.7 g/day correlated with larger left atrial and left ventricular dimensions (p<0.05).
Adjustments for several factors (such as speckle-tracking analyst, image quality, age, sex, study site, alcohol use, smoking status, daily blocks walked, diuretic use, estimated glomerular filtration rate, left ventricular mass, ejection fraction and wall motion score index) revealed that ESI >3.7 g/day was associated with both strain parameters and e’ velocity (p<0.05 for all comparisons), but ESI ≤3.7 g/day was not (p>0.05 for all comparisons).
Potassium excretion showed significant interactions for circumferential strain.
Based on mediation analysis, SBP explained 14 and 20 percent of indirect effects between ESI and LS and e’ velocity, respectively. On the other hand, serum aldosterone explained 19 percent of the indirect effects between ESI and LS.