Iranian Journal of

Background: kallikrein 7 (KLK7), a serine protease with a chymotrypsin-like specificity, is able to cleave human insulin in the A- and B-chain. The aim of this study was to investigate the effects of aerobic exercise training on plasma KLK7 concentration and insulin resistance index (HOMA-IR) in normal and overweight sedentary women.

Methods: Twenty-eight sedentary women, aged 24-60 years, voluntary participated in this study and according to body mass index status divided into normal (n=15) and overweight (n=13) groups. All subjects completed an 8-week progressive aerobic exercise training program (running with 40- 80% Heart rate reserve). Metabolic and Anthropometric (body weight, BMI, body fat percentage) parameters in addition to plasma KLK7 concentrations were measured at baseline and end of training program.

Results: Body fat percentage significantly decreased (P<0.05) and maximum oxygen consumption increased (P<0.05) by this training program in both training groups. At baseline, plasma KLK7 concentration in overweight women was significantly higher compared with normal weight group (P<0.05). Plasma KLK7 concentrations significantly increased after 8-week aerobic exercise training only in normal weight group (P<0.05). Changes in plasma KLK7 concentrations were not correlated with changes in insulin concentration and insulin resistance index (P<0.05).

Conclusion: Aerobic exercise training could be an effective factor to increase plasma KLK7 concentration in sedentary women. These data do not support a role of plasma KLK7 in insulin resistance alterations.