The Association of Circulating Bone Morphogenetic Protein 9 and Arterial Stiffness in Hypertensive Patients

Bone morphogenetic protein 9 (BMP9) plays an important role in vascular development and stability. However, the association between circulating BMP9 levels and arterial stiffness (AS) in hypertensive patients is not yet clear. This study enrolled 305 hospitalized patients with hypertension. Brachial-ankle pulse wave velocity (baPWV) was measured, with values ≥1800 cm/s indicating AS. Clinical characteristics and laboratory parameters were collected during hospitalization. Circulating BMP9 levels were measured with an ELISA kit. Multivariable linear regression and stepwise logistic regression analysis were used to assess the relationship between BMP9 and baPWV. A nomogram was constructed to predict AS in hypertensive patients and internally validated using the bootstrap method. Among 305 patients, 97 were diagnosed with AS. Multivariable linear regression analysis revealed that BMP9 was positively correlated with baPWV in hypertensive patients (β = 0.471, p < 0.001). Multivariate logistic stepwise regression analysis showed that age ≥ 60 years old, diabetes mellitus, SBP ≥ 140 mmHg, and higher BMP9 levels were the independent risk factors for hypertensive patients with AS. A nomogram combining these factors showed strong predictive performance (AUC: 0.804, 95% CI: 0.7503-0.8567). The calibration plot performed a good adaptability between prediction and observation (χ² = 6.60, p = 0.359) and the decision curve analysis (DCA) demonstrated the acceptable clinical utility. The addition of BMP9 to the traditional risk model had an incremental effect on the predictive value for AS (0.765 vs. 0.804, p < 0.01). The elevation of BMP9 is strongly related to AS in hypertensive patients. BMP9 may be a biomarker of AS in hypertension.