Introduction: Adipokines, expressed by adipose tissue (AT), have been associated with metabolic disturbances and coronary artery disease (CAD). The impact of exercise training on the AT in patients suffering from both diabetes and CAD is unknown. To gain knowledge on changes in ATs' inflammatory profile in such a population, we investigated the effects of long-term exercise on selected adipokines and their associations with physical performance and glucometabolic variables. Adiponectin was selected based on its anti-atherogenic and anti-diabetic properties and visfatin and tumour necrosis factor (TNF) for their association with atherosclerosis and metabolic disorders. Not many studies have focused on the effects of long-term exercise training on adipokines in patients with concomitant T2DM and CAD.
Methods: Patients with type 2 diabetes and CAD (n = 137), 41-81 years, 17.2% females, were randomized in a 1:1 manner to an exercise group, who underwent 1 year of 150 min weekly combined strength and endurance exercise, or a control group. AT from the gluteal region and blood samples were obtained at baseline and after 12 months, along with a physical performance test, assessed by the VO2 peak. Circulating protein levels were measured by ELISA. RNA was extracted from AT and expression levels were relatively quantified by PCR.
Results: After 1 year, no significant difference in the change in the investigated markers between the intervention group and the control group was observed. Changes in circulating adiponectin and VO2 peak correlated in the total population (r = 0.256, p = 0.008). At baseline, circulating adiponectin and TNF correlated inversely with insulin and with C-peptide and VO2peak, respectively (p < 0.001, all).
Conclusion: In this population with concomitant diabetes and CAD, ATs' inflammatory profile remained unchanged apparently after 1 year of exercise intervention. Changes in the VO2peak were nevertheless, related to changes in circulating adiponectin levels.
Trial registration: http://www.clinicaltrials.gov NCT01232608.
Keywords: Adiponectin; coronary artery disease; exercise-training; type 2 diabetes; vo2peak.