Association of serum thymosin 4 with malnutrition-inflammation-atherosclerosis syndrome in peritoneal dialysis patients: a cross-sectional study

Background: Malnutrition-inflammation-atherosclerosis (MIA) syndrome may worsen the prognosis of peritoneal dialysis (PD) patients. Serum thymosin beta 4 (sT beta 4) protects against inflammation, fibrosis and cardiac dysfunction. Objectives: The present study aimed to characterize the association between sT beta 4 and MIA syndrome as well as to investigate the potential of regulating sT beta 4 to improve the prognosis of PD patients. Methods: We performed a cross-sectional, single-center pilot study involving 76 PD patients. Demographic characteristics, clinical characteristics, nutritional profiles, inflammatory mediators, atherosclerosis-related factors and sT beta 4 levels were collected and subjected to association analysis for sT beta 4 and MIA syndrome. Results: sT beta 4 levels did not significantly vary with sex or primary disease in PD patients. Ages and PD features did not vary between patients with different levels of sT beta 4. PD patients with higher levels of sT beta 4 had significantly higher levels of nutritional indicators, including subjective global nutritional assessment (SGA) (p < 0.001) and serum albumin (ALB) (p < 0.001) but lower levels of inflammatory and atherosclerotic indicators, including serum C reaction protein (CRP) (p = 0.009), the right common carotid artery (RCCA) intimal thickness (p < 0.001) and the left common carotid artery (LCCA) intimal thickness (p = 0.02). Correlation analysis showed that sT beta 4 was positively associated with SGA (p < 0.001) and serum ALB (p < 0.001) but negatively associated with CRP (p = 0.020), RCCA intimal thickness (p < 0.001) and LCCA intimal thickness (p = 0.033). In multiple adjusted models, the prevalence of MIA syndrome was significantly decreased in PD patients with increased levels of sT beta 4 when patients without MIA syndrome were compared to those with all indicators of MIA syndrome (OR = 0.996, 95% CI 0.993-0.999, p = 0.003) or those with at least one indicator of MIA syndrome (OR = 0.997, 95% CI 0.995-0.998, p < 0.001). Conclusions: The sT beta 4 level decreases in PD patients with MIA syndrome. The prevalence of MIA syndrome decreases significantly as the level of sT beta 4 increases in PD patients.