Impact of lipolysis inhibition on exercise physiology in type 2 diabetes mellitus

Introduction: Endurance-type exercise, combined with adipose tissue lipolytic inhibition using acipimox, has been shown to augment intramuscular lipid use and the increase in whole-body insulin sensitivity in type 2 diabetes mellitus (T2DM) patients after a single bout of exercise but the effects of long term intervention remain to be studied. However, little is known about the exercise physiology during such an inhibition. The goal of this project is to investigate the impact of adipose tissue lipolytic inhibition on exercise physiology in T2DM patients. Methods: 10 overweight male T2DM patients participated in a double-blind placebo-controlled randomized cross-over study. After 250 mg nicotinic acid derivative acipimox or placebo subjects underwent a 12-minute indirect calorimetry measurement, followed by a maximal cardiopulmonary exercise test. Heart rate was monitored continuously and blood pressure was measured during rest and at exercise cessation. Results: RER was lowered following acipimox administration at rest and during exercise at 40-60% of VO2Peak (p < 0.05). At 6 minutes of exercise lactate concentration was increased in the acipimox group, corresponding with a leftward shift of the RCP Discussion & conclusions: Inhibiting adipose tissue lipolysis during a maximal cardiopulmonary exercise test alters substrate metabolism during moderate-intensity exercise. Moderate, not high intensity exercise may be optimal for an acipimox co-intervention.