BMP6 and Hypertension: Investigating associations between 2-methylbutyric acid and BMP-6 in a multivariable-adjusted linear regression model, the negative association (β coefficient −1.00, 95% CI −1.45 to −0.55, p < 0.001) persisted after adjusting for baseline age, sex, hemodialysis vintage, cause of ESRD, arteriovenous shunt type, comorbidities (diabetes mellitus, hypertension, and dyslipidemia), medications (antiplatelet/warfarin drugs, anti-hypertensive drugs, and diabetic treatment drugs), and clinical laboratory data (serum ionized calcium level, phosphate level, hsCRP level, and Kt/V) (Table 2).