Abstract 20436: Time-Restricted Feeding Prevents Obesity, but not Atherosclerosis in Apoe-Deficient Mice Fed High Fat Diet
Introduction: Perturbation of circadian rhythms has divergent malinfluence in metabolic and cardiovascular responses, causes obesity and hypertension. It has shown that metabolic stress induced by high-fat diet (HFD) reprograms peripheral cellular circadian rhythmicity in the liver and adipose tissues, and aggravates the obesity. Recent evidence indicates that time-restricted feeding (tRF) of HFD has beneficial effects on preventing development of obesity and insulin resistance. Notably, the beneficial effects could not be explained by food intake decrease, but by the ameliorated circadian rhythm.
Hypothesis: We assessed the hypothesis that the tRF regimen is also protective for progression of atherosclerosis in Apoe-/- mice.
Methods: Apoe-/- mice fed HFD were divided into three groups of feeding regimen; 1) Control: Ad libitum feeding, 2) tRF regimen: fasting for 8hr during the day followed by free feeding for another 16hr without caloric limitation for 5 consecutive days and ad libitum feeding for 2 days a week, and 3) Exercise (Ex) regimen: tRF regimen concomitant with forced swimming for 20 min for 5 days a week. After 14-week feeding regimen, the liver and brown adipose tissue (BAT) were analyzed with the expression of circadian clock, adipocyte heat producing and metabolic genes. Atherosclerotic lesions in the aorta were examined by Oil-Red staining.
Results: tRF was protective against obesity (34.9 ± 1.7 vs. 48.2 ± 1.0 g in control, n=10), and improved glucose tolerance test. In control group, mass of BAT increased and the size of lipid droplet remarkably increased. The amplitude of uncoupling protein (UCP)-1 mRNA oscillation were diminished, and the peak time of UCP-1 mRNA rhythm was shifted backward by 8hr. tRF regimen suppressed these changes. In aortic root, plaque areas in control, tRF and Ex regimen were 0.500 ± 0.043, 0.573 ± 0.029 and 0.395 ± 0.045 mm2, respectively (n=7-9). Progress of atherosclerosis was not affected by tRF regimen, whereas Ex regimen ameliorated it.
Conclusions: Fasting for 8hr of HFD intake in 5 days a week without caloric restriction effectively prevented obesity and reprogramming of circadian rhythms and the heat-producing factor, but did not affect atherosclerosis progression in Apoe-/- mice.
Author Disclosures: M. Domae: None. K. Inoue: None. T. Inoue: None.
- © 2016 by American Heart Association, Inc.