Asghar Tofighi, Zahra Samadian, and Alireza Mahdizadeh
We aimed to compare the changes in PRL with glycemic indices and lipid profile and also to investigate the relationship of insulin resistance (IR) with PRL in obese postmenopausal women with diabetes mellitus type 2 (DMT2) following 12-week aerobic, resistance and combined exercises, while our inclusion and exclusion criteria and also design exercise protocol differ from other studies in this field. In a quasi-experimental study for 12 weeks, 40 women with DMT2 were randomly selected by availability and purposive sampling and divided into four equal groups of aerobic training, resistance, combined and control group. Aerobic group accomplished aerobic exercise (AEX), 3x/week, for 20-50 minutes at 50-70% of maximum heart rate. Resistance group received resistance exercise (REX), 3x/week in three sets of 10 repetitions with 40-60% of one repetition maximum. The program in combined group consisted of a combination of AEX and REX with the same intensity and duration (included 2 sessions of AEX and 1 session of REX per week. But fortnightly, the numbers of these sessions were changed with each other). The control group was without exercise program. Blood samples for determination of PRL, lipid profile and glycemic indices in pre-and post-tests were collected. HOMA-IR equation was used to calculate insulin resistance. Statistical analysis was performed using SPSS software version 21. According to our finding; the effect of AEX and combined exercises was more than control group on the increasing PRL. The result of AEX in weight loss was more than REX however, the outcome of REX in insulin and IR reducing; also TC declining was more than the AEX. While the effect of combined group in decreasing body fat percent was more than AEX group, but the consequence of AEX was more than the combined group for reducing waist-to-hip ratio (WHR). The effect of the combined group in reducing low density lipoprotein (LDL) was more than the REX group. Also, weight, fasting blood glucose, insulin, triglycerides, LDL, glycosylated hemoglobin A1c and WHR were the predictors of IR. It seems that, during the study period, all three types of exercises through different mechanisms had valuable effects on glycemic indices and lipid profile in DMT2 patients. Also due to the increase in PRL and non-significant correlation with IR; it is doubtful that resistin be as a factor in the incidence of DMT2.