Altered molecular weight forms of adiponectin in hypertension

An important link between adiponectin and hypertension has been proposed in clinical studies. In the circulation, adiponectin is predominantly present in multimeric complexes, of which high-molecular weight (HMW) adiponectin is thought to represent the biological active form. The authors investigated which role the different multimeric adiponectin isoforms play in context with hypertension as compared to total adiponectin levels. Fifty (19 normotensive/31 hypertensive) patients were included in the study. Total adiponectin and adiponectin multimers were determined by enzyme-linked immunosorbent assay and western blot. The authors analyzed associations between adiponectin multimer levels and blood pressure. Total adiponectin concentrations were not significantly different between hypertensive and normotensive patients (6.8+/-2.3 vs 7.5+/-4.2 microg/mL). HMW adiponectin was significantly lower (P<.05) and low-molecular weight adiponectin was significantly higher (P<.01) in hypertensive than in normotensive persons (3.8+/-1.7 vs 5.2+/-3.0 microg/mL and 0.9+/-0.5 vs 1.8+/-0.9, respectively). Low molecular weight was an independent predictor for the presence of hypertension (effect coefficient: 0.160-0.445; P<.001) in multivariate analyses. These results suggest that the composition of the molecular weight forms of adiponectin in hypertension are characterized by reduced HMW adiponectin, the proposed major active form of adiponectin, and increased low-molecular weight adiponectin. Moreover, the latter represents an independent predictor of prevalent hypertension, suggesting an association between adiponectin multimer composition and hypertension.