Association between Phase Angle and Subclinical Atherosclerosis in Asymptomatic Adults: A Large Scale Cross-Sectional and Longitudinal Study.

Aims: The phase angle (PhA) derived from a bioelectrical impedance analysis (BIA) is a risk factor for cardiovascular disease (CVD). The present study explored the relationship between PhA and the progression of subclinical atherosclerosis in asymptomatic adults.

Methods: Two cross-sectional studies were performed on 15579 participants who underwent carotid ultrasound testing and a BIA as well as 8228 participants who underwent brachial ankle pulse wave velocity (baPWV) testing and a BIA. We also conducted a longitudinal study in participants without CVD and carotid atherosclerosis (CAS) at baseline who underwent carotid ultrasound ≥ 2 times (n = 2680) or baPWV testing [≥ 2 times] (n = 1775). CAS and the brachial ankle pulse wave velocity (baPWV) were selected as the subclinical atherosclerosis markers.

Results: In the cross-sectional studies, participants with CAS (5.43±0.60° vs. 5.73±0.61°, P＜0.001) or elevated baPWV (5.38±0.62° vs. 5.74±0.59°, P＜0.001) had lower PhA values than controls. Furthermore, the PhA value was independently and inversely correlated with CAS (adjusted odds ratio [OR] = 0.41, 95% confidence interval [CI] 0.37-0.46, P＜0.001) and elevated baPWV (adjusted OR = 0.45, 95% CI 0.39-0.52, P＜0.001). Restricted cubic spline curve analyses indicated dose-response associations of PhA values with subclinical atherosclerosis. In the longitudinal study, high PhA values at baseline decreased the risk of incident CAS (adjusted hazard ratio = 0.44, 95% CI 0.36-0.54, P＜0.001). Multivariate linear regression analyses showed that the PhA was negatively associated with absolute or relative annual changes in baPWV.

Conclusion: The PhA value is significantly associated with the progression of subclinical atherosclerosis, indicating that PhA may serve as a noninvasive marker for monitoring subclinical atherosclerosis in a primary prevention setting.