Background/Objectives: Subcutaneous adipose tissue contributes to metabolic and inflammatory responses to Western diets, partly through microRNAs. The effects of high-intensity interval training (HIIT) and ketone ester (KE) supplementation on these microRNAs are unclear. This exploratory study examined miR-21-5p, miR-155-5p, and miR-133a-5p in Western diet-fed mice.
Methods: Thirty male C57BL/6J mice were randomly assigned to five groups (n=6): control, Western diet (WD), WD plus HIIT (WD+EX), WD plus ketone ester (WD+KE), and WD plus both (WD+EX+KE). Diets were given for 8 weeks; HIIT (3 sessions/week) and/or KE (5 g/kg/day, oral gavage; vehicle in other groups) were applied during the final 4 weeks. Subcutaneous adipose tissue was collected 48 hours after the last session, and microRNAs were quantified by qRT-PCR. Data were analyzed by one-way ANOVA with Tukey’s post hoc test (P≤0.05).
Results: The Western diet increased miR-155-5p (p=0.006) and miR-21-5p (p=0.001) versus control; miR-133a-5p did not differ among groups (p=0.50). miR-155-5p was lower than in WD only in WD+EX+KE (p=0.014; WD+EX p=0.074, WD+KE p=0.329), and the combined group did not differ from the single-intervention groups. miR-21-5p was lower in WD+EX (p=0.017) and WD+EX+KE (p<0.001) but not in WD+KE (p=0.095), with no differences among the intervention groups.
Conclusions: HIIT plus KE significantly lowered miR-155-5p, whereas either alone did not; miR-21-5p was lowered only with HIIT-containing interventions. The combination was not shown to be superior to either alone. miR-133a-5p findings were inconclusive given limited power. Physiological consequences were not measured; mechanistic studies and trials are needed.