Novel use of structural equation modelling to examine diet and metabolic traits associated with microvascular endothelial dysfunction in middle-aged Chinese males: a cross-sectional study

Background The present study aims to use structural equation modelling (SEM) with multiple regression pathways to examine direct and indirect links from diet and metabolic traits to microvascular endothelial dysfunction (ED) among middle-aged Chinese males. Methods The study was conducted in middle-aged Chinese males, who underwent a health check-up between 2018 and 2019. Data on lifestyle behaviour factors (physical activity, diet pattern, sleep quality and diet data underwent factor analysis in advance) and metabolic risk factors referring to metabolic traits were introduced into the SEM to examine inter-relationship among these factors and their association with ED, as evaluated by the reactive hyperaemia index (RHI). Results Both exploratory factor analysis and confirmatory factor analysis identified two major dietary patterns: 'prudent pattern' and 'western pattern'. The univariate test suggested that only triglycerides (TGs) and prudent dietary pattern were directly associated with RHI. Furthermore, prudent dietary pattern had an indirect association with RHI via TG (prudent diet -> TG: beta=-0.15, p<0.05; TG -> RHI: beta=-0.17, p<0.001). As to confirming the hypothesised association between variables apart, physical activity frequency was correlated to the decrease in TG (beta=-0.29, p<0.001), but had no direct correlation to RHI. Conclusion The network of direct and indirect associations among diet pattern and cardiometabolic risk factors with RHI measured ED among middle-aged males. The most significant modifiable factors identified were TG and prudent diet pattern, which needs to be targeted as preventive strategies for early microvascular impairment.