Effects of Exercise Training and Weight Loss on Plasma Fetuin-A Levels and Insulin Sensitivity in Overweight Older Men

Aerobic exercise training and weight loss (aex+wl) improves insulin sensitivity in overweight adults; however,the underlying pathways are incompletely understood. fetuin-a,a hepatokine that inhibits insulin signaling,may be involved in the salutary effects of aex+wl. therefore,we examined the effects of 6-month aex+wl on plasma fetuin-a levels (36-48 hours after the last bout of exercise),aerobic capacity (vo2max),body composition,glucose tolerance,and insulin sensitivity (m) in 16 sedentary,overweight-obese older men (age = 60 ± 2 years,bmi = 31 ± 1 kg/m2) with no history of cardiovascular disease or diabetes. at baseline,fetuin-a levels correlated directly with adiposity and had a borderline inverse correlation with m. after aex+wl,body weight decreased by 10 kg,while both vo2max and m increased by 16% (p<0.005 for all). contrary to our hypothesis,plasma fetuin-a levels increased after aex+wl (1.16 ± 0.10 g/l versus 1.70 ± 0.19 g/l,p=0.006). this increase was unrelated to changes in body composition or glucose metabolism,but directly correlated with changes in vo2max (r=0.57,p<0.05). thus,in overweight-to-obese older men,aex+wl appears to increase plasma fetuin-a levels. although not associated with improvements in insulin sensitivity,this increase in fetuin-a was related to improvements in aerobic capacity and could be representative of the cardioprotective effects of aex+wl in older men. © 2017 jacob b. blumenthal et al.