Divergent Effects of Caloric Restriction and Endurance Training on Adipose Macrophage-Related Gene Expression in Aged Wistar Rats

Adipose tissue dysfunction, chronic low-grade inflammation, and impaired metabolic regulation occur in aging. We examined the effects of caloric restriction (CR), endurance training (ET), and their combination on adipose macrophage-related gene expression and systemic metabolic indices in aged rats. Male rats (26-months-old) were randomized to control (CON), CR, ET, or CR+ET groups for a 6-week intervention (n = 9/group). CR consisted of a 30% reduction in food intake (weeks 1-2) followed by 20% restriction (weeks 3-6). ET was performed 5 days/week using a treadmill at 60% maximal aerobic speed. Epididymal adipose tissue was analyzed by RT-qPCR for CD11c and CD206 mRNA expression. Fasting glycemic and lipid-related variables were assessed. CR increased CD11c and CD206 expression, indicating non-specific upregulation of macrophage-associated transcription rather than a selective polarization shift. ET alone did not alter either marker relative to CON, but a combination with CR attenuated the CR-associated transcriptional response, particularly for CD11c. The CD11c/CD206 expression ratio showed greater variability with combined treatment. Fasting glucose, insulin, HOMA-IR, QUICKI, HOMA-β, TyG, conventional lipid parameters, and most atherogenic indices were not altered. CR and ET exert distinct effects on adipose macrophage-related gene expression in aged rats, whereas systemic metabolic markers remain largely unchanged.