The associations of adipokines with hypertension in youth with cardiometabolic risk and the mediation role of insulin resistance: The BCAMS study

The mechanisms link obesity and hypertension are not well understood. One possibility is the alterations in adipose-derived adipokines that modulate insulin resistance (IR) and cardiovascular homeostasis. We aimed to assess the associations between hypertension and four adipokine levels in Chinese youth, and to examine to what extent the associations are mediated by IR. We utilized cross-sectional data from the Beijing Children and Adolescents Metabolic Syndrome (BCAMS) Study Cohort (n = 559, mean age = 20.2 years). Plasma leptin, adiponectin, retinol binding protein 4 (RBP4) and fibroblast growth factor 21 (FGF21) levels were assayed. The relationships between adipokines and hypertension and the possible mediation effect of IR were evaluated. Youth with hypertension have lower adiponectin and higher leptin, FGF21 (all P < 0.001) and RBP4 levels (p = 0.06) compared to their counterparts. Moreover, the co-existence of these two or more adipokine abnormalities in youth leads to a 9-fold increased risk for hypertension (OR: 9.19; 95% CI, 4.01–21.08) compared with these without abnormalities. However, in the fully adjusted and BMI-adjusted analyses, only FGF21 was a significant predictor of hypertension (OR: 2.12; 95% CI, 1.34–3.36). Mediation analysis revealed that the associations between leptin, adiponectin, RBP4 and hypertension are totally mediated by IR (proportion: 63.9%, 65.4%, and 31.6%, respectively), while BMI and IR partly mediated the association between FGF21 and hypertension (proportion: 30.6%, 21.2%). Our findings suggest that dysregulation of adipokines might result in hypertension in youth. Leptin, adiponectin and RBP4 may exert their functions in hypertension through adiposity-related IR, whereas FGF21 might be used as an independent marker of hypertension in youth.