Exercise Training Reduces Inflammation of Adipose Tissue in the Elderly: Cross-Sectional and Randomized Interventional Trial
Abstract
CONTEXT: Metabolic disturbances and a pro-inflammatory state associated with aging and obesity may be mitigated by physical activity or nutrition interventions. OBJECTIVE: The aim of this study is to assess whether physical fitness/exercise training (ET) alleviates inflammation in adipose tissue (AT), particularly in combination with omega-3 supplementation, and whether changes in AT induced by ET can contribute to an improvement of insulin sensitivity (IS) and metabolic health in the elderly.
DESIGN, PARTICIPANTS, MAIN OUTCOME MEASURES: The effect of physical fitness was determined in cross-sectional comparison of Trained and Untrained older women (71+-4 years, n=48); and in double-blind randomized intervention by 4 months of ET with or without omega-3 (Calanus oil) supplementation (n=55). Physical fitness was evaluated by Spiroergometry (maximum graded exercise test) and Senior Fitness Tests.
IS was measured by hyperinsulinemic-euglycemic clamp. Samples of subcutaneous AT were used to analyze mRNA gene expression, cytokine secretion and immune cell populations.
RESULTS: Trained women had lower mRNA levels of inflammation and oxidative stress markers, lower relative content of CD36+ macrophages and higher relative content of γδT-cells in AT when compared to Untrained women. Similar effects were recapitulated in response to a 4-month ET intervention.
Content of CD36+ cells, γδT-cells and mRNA expression of several inflammatory and oxidative-stress markers correlated to IS and cardiorespiratory fitness. CONCLUSIONS: In older women, physical fitness is associated with less inflammation in AT.
This may contribute to beneficial metabolic outcomes achieved by ET. When combined with ET, omega-3 supplementation had no additional beneficial effects on AT inflammatory characteristics.