Bi-directional and temporal relationship between elevated alanine aminotransferase and hypertension in a longitudinal study of Chinese adults

Despite the strong correlation between elevated alanine aminotransferase (ALT) and hypertension, their bi-directional and temporal relationship are currently unclear. Our study aimed to explore the bi-directional and temporal association between elevated ALT (ALT > 40 U/L) and hypertension. Measurements of alanine aminotransferase and blood pressure were obtained twice from 2013 to 2017 in 3314 Chinese adults without cardiovascular disease at baseline. Bi-directional and cross-lagged panel analyses were performed to dissect the temporal relationship between elevated ALT and hypertension. Longitudinally, we found that baseline elevated ALT was strongly correlated with incident hypertension (odds ratios = 2.16, P = .001), and baseline hypertension was also significantly associated with incident elevated ALT (odds ratios = 1.64, P = .026). The cross-lagged path coefficients from baseline ALT to follow-up blood pressure were significantly greater than that from baseline blood pressure to follow-up ALT (β: 0.043 vs. 0.026, P < .05 for systolic blood pressure and β: 0.052 vs. 0.024, P < .05 for diastolic blood pressure). Our results provide evidence for the bi-directional association of elevated ALT and hypertension among Chinese adults, and elevated ALT probably antedates the development of hypertension.