The effect of paraaortic fat tissue thickness measured by transthoracic echocardiography on diastolic function in young individuals

Aim: The aim of this study is to evaluate the relationship between paraaortic adipose tissue (PAT) thickness measured by transthoracic echocardiography and left ventricular diastolic function parameters in the young age group. Material and Methods: This cross-sectional study included a total of 254 individuals aged 18–55 who visited the cardiology outpatient clinic. Participants' detailed medical histories were obtained, and body mass index (BMI), body surface area (BSA), and routine biochemical tests were recorded. Ejection fraction, left ventricular mass index, and diastolic function were assessed using transthoracic echocardiography. PAT thickness was defined as a hypoechoic space 2 cm above the sinotubular junction of the ascending aorta and measured in millimetres using echocardiography. The IBM SPSS program was used for statistical analyses, and correlation, univariate, and multivariate regression analyses were performed between parameters. Results: Diastolic dysfunction was detected in 27.1% of participants (n=69). In the diastolic dysfunction group, age (p < 0.001), body mass index (p = 0.005), body surface area (p = 0.043), and PAT thickness (9.09 ± 4.26 mm vs. 6.91 ± 4.57 mm; p = 0.003) were significantly higher. Additionally, left atrial diameter (p = 0.016), aortic diameter (p < 0.001), relative wall thickness (p = 0.003), and left ventricular mass index (p = 0.012) were also significantly increased in this group. In univariate regression analysis, PAT (OR = 1.10; 95% CI: 1.03–1.19; p = 0.003), age (OR = 1.12; 95% CI: 1.05–1.21; p < 0.001), hypertension (OR = 2.78; 95% CI: 1.49–5.17; p = 0.001), BMI (OR = 1.08; 95% CI: 1.02–1.16; p = 0.009), and RDW (OR = 1.15; 95% CI: 1.01–1.31; p = 0.032) were significantly associated with diastolic dysfunction. However, in multivariate analysis, only age remained an independent predictor (p = 0.045; OR = 1.089; 95% CI: 1.002–1.183). In correlation analysis, PAT correlated with age (r = 0.41; p < 0.001), BMI (r = 0.33; p < 0.001), BSA (r = 0.37; p < 0.001), LA diameter (r = 0.34; p = 0.012), RWT (r = 0.33; p = 0.014), and LVMI (r = 0.35; p = 0.009), while a negative correlation was found with the E/A ratio (r = –0.39; p < 0.001). Conclusion: Para-aortic adipose tissue thickness, which can be measured by transthoracic echocardiography, has been found to be associated with diastolic dysfunction in young individuals. However, PAT is not an independent predictor independent of traditional risk factors such as age and obesity. These results suggest that adipose tissue around the aorta may play a role in the pathophysiology of diastolic dysfunction and may be considered a risk marker in the subclinical period.