A recent study published in Nature Metabolism explores the impact of long-term exercise on abdominal subcutaneous adipose tissue (aSAT) in overweight and obese individuals. Conducted by researchers in the United States, the study reveals that exercise leads to significant improvements in aSAT, which could enhance cardiometabolic health.
Study Overview
The research examined how regular endurance exercise affects aSAT, focusing on changes in capillary density, macrophage presence, and protein levels related to key metabolic processes. The findings indicate that those who exercise regularly exhibit higher capillary density and fewer macrophages in their abdominal fat. Additionally, there is a greater presence of proteins involved in angiogenesis, mitochondrial function, and lipid storage, which are linked to improved cardiometabolic health.
Background
Previous studies have shown that abnormalities in aSAT are associated with insulin resistance and other metabolic issues. These include fibrosis, reduced capillary networks, and inflammation, which can disrupt fat metabolism and lead to insulin resistance and inflammation in other organs. While exercise is recommended to combat obesity-related health issues, most studies have been limited by weight loss or short durations. This study aimed to fill this gap by focusing specifically on the effects of long-term endurance exercise without weight loss.
Study Details
The study involved 52 adults with a body mass index (BMI) ranging from 25 to 40 kg/m². Participants were divided into two groups based on self-reported activity levels: 28 sedentary individuals and 24 regular exercisers. The exercisers had engaged in moderate to vigorous aerobic exercise for over 30 minutes at least four days a week for more than two years.
To compare, 16 sedentary individuals were matched with 16 exercisers based on age, sex, body weight, and BMI. Some exercisers also participated in resistance training. Researchers analyzed adipose tissue samples from a subset of participants to study changes in aSAT.
Findings
Exercisers reported nearly ten times more physical activity than sedentary individuals and had a 25% higher peak oxygen uptake. They also exhibited lower levels of insulin resistance and higher levels of high-density lipoprotein (HDL) cholesterol. Notably, exercisers had higher levels of total adiponectin but similar levels of high-molecular weight adiponectin and leptin compared to sedentary participants.
Adipose tissue characteristics showed that while adipocyte size was similar between groups, exercisers had higher capillary density and levels of vascular endothelial growth factor α (VEGFα). There was also an increase in mitochondrial proteins and ribosomal subunits in the aSAT of exercisers, indicating improved protein synthesis and mitochondrial function. Furthermore, exercisers had lower levels of Col6a, a collagen type linked to metabolic issues, and reduced markers of macrophage presence.
Proteomic analysis identified 2,536 proteins, with 158 showing significant differences between the groups. Exercise appeared to activate key metabolic pathways, including the AMPK signaling pathway, which is vital for mitochondrial biogenesis and lipid metabolism.
Conclusion
The study underscores the benefits of sustained regular exercise for improving aSAT health and overall metabolic function in overweight and obese individuals. Exercise enhances the metabolic activity of aSAT by upregulating important pathways, contributing to better lipid storage and energy metabolism.
While short-term exercise can produce some benefits, the study suggests that more significant health improvements require longer periods of consistent exercise.
