The effect of body weight on left atrial function determined by longitudinal strain analysis in young adults

Obesity is a risk factor for various cardiovascular disorders. Left atrial (LA) function is vital for predicting adverse outcomes in many diseases. LA strain was recently proposed as a noninvasive and valuable parameter for LA functional evaluation. We investigated the effect of body mass index (BMI) values on left atrial functions determined by longitudinal strain analysis in young adults without concomitant disease.

We prospectively included 134 subjects in our study. Participants were categorized into three subgroups, obese, overweight, and control, according to their BMI. Conventional echocardiographic measurements and strain analysis were performed on all patients.

There were 41 patients (30.5%) in the obesity group, 46 patients (34.3%) in the overweight group, and 47 patients (35.0%) in the control group. Obese patients had significantly larger LA volume (46.9 ± 12.1 ml; p < 0.001) compared to overweight and control subjects; however, LA volume index (21.4 ± 6.1 ml/m² vs. 22.4 ± 6.1 ml/m² vs. 22.4 ± 5.0 ml/m²; p = 0.652) were similar between groups. In the LA strain analysis, obese patients were found to have lower left atrial reservoir longitudinal strain (LASr) compared to both the overweight and control group (44.2 ± 5.8% vs. 39.1 ± 3.7% vs. 36.5 ± 4.9%; p < 0.001); moreover obese patients had significantly worse left atrial contraction phase longitudinal strain (LASct) (-15.1 ± 3.1% vs. -13.1 ± 2.5%; p = 0.007) and left atrial conduit phase longitudinal strain (LAScd) (-29.0 ± 7.1% vs. -23.3 ± 5.4%; p < 0.001) values compared to the control group. However, LASct and LAScd values did not differ between overweight and obese patients.

LA function determined by LA strain analysis was impaired in obese and overweight individuals compared to the control group, even in the early stages of life. The prognostic significance of this finding should be investigated in prospective studies.