A 16‑week program of combined aerobic and resistance training raised the blood level of the mitochondrial peptide MOTS‑c in non‑Hispanic White women who had survived breast cancer. The rise was linked to losing fat, gaining lean muscle, and better insulin and inflammation markers. Hispanic participants did not show the same peptide increase.

MOTS-c is a mitochondrial derived peptide with exercise mimetic activity that elicits beneficial effects on metabolism and exercise capacity. Furthermore, MOTS-c effects in humans are affected by race, potentially via ethnic-specific mtDNA variations. Women treated for breast cancer are at an increased risk for cardiovascular disease, diabetes and obesity, due to side effects of cancer-treatments. We conducted a secondary analysis of the effects of a 16-week aerobic and resistance exercise intervention on MOTS-c in Hispanic and Non-Hispanic White breast cancer survivors (BCS). BCS (Stage I-III) were randomized to exercise or standard care. The intervention promoted aerobic and resistance exercise for 16 weeks. MOTS-c was analyzed in fasting plasma using an in-house ELISA. Within and between group differences were assessed by paired t-test and repeated measures ANOVA. Pearson's correlation was computed to assess the association between MOTS-c and metabolic biomarkers at baseline and post-exercise. Twenty-five Hispanic-BCS and 24 non-Hispanic White BCS were included. Hispanic BCS were younger, of greater adiposity, had higher stage cancers, and had worse metabolic profiles at baseline compared to non-Hispanic White BCS (p < 0.001). Post-exercise, MOTS-c levels significantly increased when compared to baseline and the usual care group among non-Hispanic White BCS (p < 0.01) but not among Hispanic breast cancer survivors (p > 0.01). Post-exercise levels of MOTS-c among non-Hispanic White BCS were significantly associated with reductions in fat mass, body weight, HOMA-IR, CRP, and an increase in lean mass (p < 0.01). A 16-week aerobic and resistance intervention increased MOTS-c levels among non-Hispanic White BCS. Trial registration: This trial is registered on ClinicalTrials.gov: NCT01140282 as of June 9, 2010. https://clinicaltrials.gov/ct2/show/NCT01140282 .