Exercise-Induced Changes in Visceral Adipose Tissue Mass Are Regulated by IL-6 Signaling: A Randomized Controlled Trial
Anne-Sophie Wedell-Neergaard CLINICAL AND TRANSLATIONAL REPORT| VOLUME 29, ISSUE 4, P844-855.E3, APRIL 02, 2019
Highlights
• Exercise reduces visceral adipose tissue mass
• Loss of visceral adipose tissue mass following exercise is dependent on IL-6
• IL-6 receptor blockade increases total cholesterol and is not influenced by exercise
• Improvements in cardiorespiratory fitness following exercise are not IL-6 dependent
Visceral adipose tissue is harmful to metabolic health. Exercise training reduces visceral adipose tissue mass, but the underlying mechanisms are not known. Interleukin-6 (IL-6) stimulates lipolysis and is released from skeletal muscle during exercise. We hypothesized that exercise-induced reductions in visceral adipose tissue mass are mediated by IL-6.
In this randomized placebo-controlled trial, we assigned abdominally obese adults to tocilizumab (IL-6 receptor antibody) or placebo during a 12-week intervention with either bicycle exercise or no exercise. While exercise reduced visceral adipose tissue mass, this effect of exercise was abolished in the presence of IL-6 blockade. Changes in body weight and total adipose tissue mass showed similar tendencies, whereas lean body mass did not differ between groups. Also, IL-6 blockade increased cholesterol levels, an effect not reversed by exercise.
Thus, IL-6 is required for exercise to reduce visceral adipose tissue mass and emphasizes a potentially important metabolic consequence of IL-6 blockade.