Cardiotrophin-1 as a mediator between systolic blood pressure and left ventricular hypertrophy in obesity

AIMS: Left ventricular hypertrophy (LVH) is prevalent in obesity. Cardiotrophin-1 (CT-1), an interleukin-6 family cytokine implicated in myocardial remodeling, has an unclear role in obesity-associated LVH. This study examined whether CT-1 mediates the association between systolic blood pressure (BP) and left ventricular (LV) mass index in obesity. METHODS: Seventy-three adults with body mass index (BMI) ≥35 kg/m 2 underwent clinical evaluation, echocardiography, and serum CT-1 measurement. Mediation analysis was performed using SPSS PROCESS macro (Model 4), with systolic BP as the independent variable, CT-1 as the mediator, and LV mass index as the dependent variable, adjusting for age, sex, and BMI. RESULTS: Mean BMI, systolic BP, LV mass index, and CT-1 level were 42.4 ± 5.7 kg/m 2 , 146 ± 15 mmHg, 50.7 ± 11.8 g/m 2.7 , and 283.07 ± 632.94 pg/ml, respectively. LV mass index correlated with BMI ( r = 0.533, P < 0.001) and systolic BP ( r = 0.267, P = 0.022). CT-1 correlated with systolic BP ( r = 0.300, P = 0.010) and LV mass index ( r = 0.325, P = 0.005), but not BMI. Mediation analysis showed CT-1 fully mediated the systolic BP-LV mass index association, with a significant indirect effect ( B = 0.070, 95% CI [0.007, 0.168]) and a non-significant direct effect ( B = -0.042, P = 0.600, 95% CI [-0.201, 0.117]). CONCLUSION: CT-1 mediates the effect of BP on LV mass in severe obesity, suggesting that CT-1 may be a biomarker or therapeutic target in obesity-associated LVH.