The effects of high-intensity interval training on cardiac fibrosis biomarkers in rats with methamphetamine-induced cardiac fibrosis

BACKGROUND: Methamphetamine (METH) use is associated with significant cardiac damage, including the development of cardiac fibrosis. While high-intensity interval training (HIIT) has demonstrated cardio-protective effects in various cardiovascular conditions, its potential role in mitigating METH-induced cardiac fibrosis remains unclear. This study aimed to investigate the effects of HIIT on the mRNA expression of cardiac fibrosis biomarkers in METH-dependent rats. METHODS: In this experimental study, the expression of collagen 1a1 (COL1A1), collagen 3a1 (COL3A1), periostin (POSTN), and alpha smooth muscle actin (α-SMA) genes was measured using real-time PCR across four groups: Sham, METH, METH-control (METH-CON), and METH-HIIT. Rats in the METH-HIIT group underwent an 8-week HIIT protocol during the withdrawal period following METH administration. RESULTS: Twenty-one days of METH administration significantly increased the mRNA expression of all measured fibrosis-related (P<0.05). However, the subsequent HIIT intervention did not significantly attenuate the elevated mRNA expression of these markers (P>0.05). CONCLUSIONS: These findings suggest that HIIT does not reverse METH-induced upregulation of cardiac fibrosis markers. Further studies are warranted to explore alternative or complementary interventions in the context of METH-associated cardiac fibrosis.