L-shaped association between ankle-brachial index and coronary heart disease in Chinese adults with hypertension

BackgroundPrior research has established that an ankle-brachial index (ABI) <= 0.9 is positively correlated with cardiovascular events, including coronary heart disease (CHD). The present study aimed to elucidate the dose-response relationship between ABI and CHD within a hypertensive population.MethodsWe conducted a cross-sectional analysis involving 10,900 hypertensive patients, with CHD as the primary outcome. A generalized additive model (GAM) and fitted smoothing curve were employed to assess linearity and delineate the dose-response association between ABI and CHD.ResultsThe cohort had a mean (SD) age of 68.3 (9.25) years, with 5129 (47.06%) being male. CHD was present in 552 (5.06%) participants. The fully adjusted odds ratio (OR) for CHD associated with ABI levels was 0.75 (95%CI 0.33-1.71). An L-shaped relationship between ABI and CHD was identified, with an inflection point at 1.07. Below this threshold, ABI showed a negative correlation with CHD (OR: 0.27; 95%CI 0.08-0.84), whereas above it, the association was not significant (OR: 3.08; 95%CI 0.60-15.80).ConclusionsIn Chinese adults with hypertension, ABI exhibits a nonlinear, L-shaped association with CHD, with the inflection point at 1.07.