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

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 (VO2, 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.