Influence of obesity on heart function in an experimental model of heart failure with preserved ejection fraction - 25/09/20
Résumé |
Introduction |
Obesity has become a prevalent pathology, especially in the developed world, being associated with the activation of numerous pathophysiologic mechanisms which may lead to cardiovascular diseases.
Objective |
Our study aimed at assessing cardiac function in a rat model of heart failure and obesity.
Methods |
Sprague-Dawley male rats (wild type, WT) and transgenic rats overexpressing β3-adrenergic receptors in endothelial cells (TGβ3) were either fed with standard diet (WT+SD, n=12; TGβ3+SD, n=12) or with hypercaloric diet (SD+HD, n=12; TGβ3+HD, n=12). For 35 weeks body-weight (BW), systolic blood pressure (SBP), echocardiographic structural and functional parameters were monitored. Oral glucose tolerance test (OGTT) was also performed.
Results |
HD induced an increase in BW in HD groups (∼10.08% for WT and ∼10.45% for TGβ3) since week 10 (W10), trend maintained until the end of the study. Regardless of WT or TGβ3 status, SBP (mmHg) was significantly increased by HD (∼12%), as measured at W35. Also, in the HD groups, hyperglycemia during OGTT was observed, suggesting insulinoresistance. Starting with W25, a decrease in early-to-late filing ratio (E/A ratio) in TGβ3+HD vs. TGβ3+SD was observed (0.97±0.04 vs. 1.11±0.07), while for WT+HD vs. WT+SD, reduction occurred at W35 (0.99±0.06 vs. 1.25±0.05). E’/A’ ratio followed the same trend, at W25: TGβ3+HD vs. TGβ3+SD (0.93±0.05 vs. 1.07±0.05), at W35: WT+HD vs. WT+SD (0.99±0.06 vs. 1.19±0.04). At W35, no significant change was registered in ejection fraction (%) between all groups (∼63%), suggesting no systolic dysfunction at this timepoint.
Conclusions |
HD increased BW, SBP and glycemia. Alteration of diastolic function occurs at around W35 in obese WT rats, whereas in obese TGβ3 rats diastolic function alteration occurred earlier (W25).
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Vol 12 - N° 2-4
P. 248-249 - octobre 2020 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.