Effects of aerobic exercise at different times on aortic lipid deposition in mice with early atherosclerosis

OBJECTIVE: To investigate the effects of aerobic exercise at different times on aortic lipid deposition in mice with early atherosclerosis (AS). METHODS: Eight-week-old C57BL/6 mice were randomly assigned to a control group (fed standard chow), an AS model group, and zeitgeber time (ZT) 1, 13, and 22 groups. An early AS model was established by feeding a high-fat diet for 16 w. Starting in week 17, the exercise groups underwent 8 w of treadmill training at 3 specific daily time points, respectively. After the final exercise session, the entire aorta was dissected out for the various assessments. RESULTS: Compared with the AS model group, all exercise groups showed improvements in dyslipidemia and aortic lipid deposition, with the ZT22 group showing the best effects, characterized by significantly reduced total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels (P<0.05), fewer aortic plaques, an increased number of autophagosomes, and significantly enhanced colocalization of LC3 and PLIN2 (P<0.05). CONCLUSIONS: Aerobic exercise at ZT22 was most effective in alleviating aortic lipid deposition in mice with early AS. This alleviating effect may be associated with its degradation of lipid droplets through the autophagy pathway.