Exercise training is associated with changes in adipocyte size and lipid metabolism in older women: cross-sectional...

Adaptations in subcutaneous adipose tissue (SAT) metabolism may contribute to cardiometabolic health improvements in response to exercise training, especially during aging. Here we investigated the potential effects of long- and short-term exercise on adipogenesis and lipid metabolism in adipose tissue of older women (age 61-80 years). The effects of long-term (> 5 years) physical activity and short-term (4 months) exercise training were evaluated, with a focus on adipocyte size, adipogenic capacity, gene expression related to lipolysis, lipogenesis, and peroxisomal β-oxidation, along with lipidomic and proteomic analysis.The difference between long-term physically active/physically fit (Trained) and less physically active (Sedentary) older women was analyzed in cross-sectional study (Sedentary, n = 29: age 72 ± 4 yrs, BMI 25.9 ± 2.6 kg/m²; Trainedn = 28: age 69 ± 4 yrs, BMI 25.1 ± 2.3 kg/m²). The effect of short-term exercise training (ET) was observed during 4-months of combined ET in group of 23 women (age 70 ± 4 yrs, BMI 27.2 ± 4.1 kg/m²).Both physical activity durations were associated with reduced adipocyte hypertrophy, which was driven by changes in adiposity. No significant changes in adipose capacity to differentiate was observed. Long-term physical activity increased mRNA expression of β-adrenergic receptors (ADRB1, ADRB2) and elevated very-long chain fatty acid (VLC-FA) levels, correlating positively with cardiorespiratory fitness (VO_{2, peak}). Altogether, these findings suggest novel hypotheses regarding SAT metabolic adaptations that may support metabolic health in older women, warranting further investigation in larger cohorts.New & noteworthyOur study reveals that SAT adipogenic capacity remains largely unaffected by physical activity in older women. However, the observed link between elevated β-adrenergic receptor expression, VLC-FA levels, and fitness suggests potential adipose tissue-specific adaptations that might mediate the positive effects of exercise in older age.