Adiponectin negatively correlated with carotid arterial structure in the leptin-resistant Zucker diabetic fatty rat

Background Despite adipocytokines are implicated in arterial hemodynamic and stiffness, their effects on arterial histomorphometry remain poorly explored. The aim of the present study was to evaluate, in Zucker Diabetic Fatty (ZDF) rats, a model of type 2 diabetes with leptin resistance, carotid arterial structural changes and their determinants, with special focus on adiponectin and leptin. Methods Proximal aortic blood pressure (BP) was measured in conscious ZDF rats ( n = 6–8) and their Lean controls ( n = 6–8) at 6, 12 and 24 weeks. The contralateral carotid was harvested and fixed at the mean BP for histomorphometric quantification. Results Mean BP was similar in both strains and increased with age ( p < 0.001). Medial thickness, luminal cross-sectional area (LCSA), medial cross-sectional area (MCSA) and wall stress (WS) increased with age ( p < 0.001). LCSA and WS were higher in Lean than in ZDF rats ( p < 0.001 for both). Leptin levels were higher in ZDF than in Lean rats ( p < 0.001) but remained unchanged during development in ZDF rats. Adiponectin levels decreased with age in ZDF rats ( p < 0.001) but remained unchanged in Lean rats. In all rats, adiponectin negatively correlated with medial thickness ( r = −0.50, p < 0.01), LCSA ( r = −0.64, p < 0.001), MCSA ( r = −0.59, p < 0.001) and WS ( r = −0.43, p < 0.05). These correlations were significant ( p < 0.001) in ZDF rats considered separately ( r = −0.73, r = −0.87, r = −0.83 and r = −0.79, respectively) but not in Lean rats; independently of mean BP and age after stepwise regression analyses. Conclusion These associations suggest a protective role for adiponectin against arterial wall thickening and wall stress. However for causal relation, further investigation is needed.