Effect of 6 months aerobic training on plasma leptin levels as a breast cancer risk factor inpostmenopausal women

Introduction: Physical activity is a well-known modifiable behavior for reducing breast cancer risk in postmenopausal women. However the underlying mechanisms are unknown. This study investigated how 6 months aerobic physical exercise can change leptin level, as a breast cancer risk factor, in postmenopausal women.Methods: This study was a randomized controlled trial. The study Participants were ages 50 to 74 years, sedentary and postmenopausal that randomly allocated to exercise or control group. Participants in intervention group engaged in aerobic exercise for 3 days per week for 6months, at 70- 80% of maximum heart rate. Blood sampling was taken at baseline and after 6-months. Plasma concentration of leptin was assessed using ELIZA kit. Intention-to-treat analyses were performed using independent-sample T test.Result: We had 41 women (19 in control and 22 in exercise group) at baseline and 27 women at 6 months (14 in control group and 13 in exercise group). Average age and BMI of participants were 54.5±5.8 and 27.9±3.2 respectively. Plasma leptin decreased 0.6% in exercisers and increased 8.2% in controls ,although the exercise effect was not statistically significant (p value=0.08).Discussion and conclusion: leptin levels slightly decreased in exercisers but increased in control group Thus, regular aerobic exercise might decrease breast cancer risk in postmenopausal women through decreased leptin levels.

Keywords:

aerobic exercise , leptin , postmenopausal , breast cancer