The study measured a tiny protein called MOTS‑c in the blood of people with obesity and people with normal weight. It found that the amount of MOTS‑c was about the same in both groups, but it tended to be higher in people who had more insulin resistance and lower in older people. It didn’t link MOTS‑c to inflammation or blood‑vessel health.

To investigate the Mitochondrial Open Reading Frame of the 12S rRNA type-c (MOTS-c) peptide levels in individuals with obesity compared to those with a normal body mass index and to examine the association of MOTS-c levels with markers of insulin resistance, endothelial function, and inflammation. In this study 85 individuals were enrolled, including 48 with a body mass index ≥ 30 kg/m2 and 37 with a body mass index between 18.5 and 24.9 kg/m2. Individuals with smoking, pregnancy, type 2 diabetes mellitus and other chronic conditions were excluded. Blood samples were collected after at least 8 hours of fasting to measure serum MOTS-c, insulin, high-sensitivity C-reactive protein, and asymmetric dimethylarginine levels. Statistical analyses included t-tests, Mann-Whitney U tests, Chi-squared tests, correlation analyses, and multiple regression analyses. We found no significant difference in serum MOTS-c levels between individuals with obesity and those with normal body mass index (14.33 ± 3.76 pg/mL versus 13.67 ± 3.44 pg/mL; p = 0.395). Serum MOTS-c levels showed a significant positive correlation with the HOMA-IR index (p < 0.05) but did not correlate with high-sensitivity C-reactive protein or asymmetric dimethylarginine levels. Multiple regression analysis indicated that age and HOMA-IR were significant predictors of MOTS-c levels, with MOTS-c decreasing with age and increasing with higher insulin resistance. Serum MOTS-c levels were similar in individuals with obesity and those with normal weight. The study highlighted age and insulin resistance as significant determinants of MOTS-c levels.