Background and Objectives: Coronary artery disease (CAD) is the leading cause
of death worldwide. It is well established that low level of high-density lipoproteincholesterol (HDL-C) is a strong and independent risk factor for CAD. Apolipoprotein M (apoM)
is a component of HDL, which is involved in pre-β-HDL formation and cholesterol efflux to
HDL. It is believed that resistance and aerobic exercise can significantly reduce risk of
cardiovascular disease, especially by increasing serum levels of HDL-C. However, little is
known about effects of these activities on HDL-apoM levels. The aim of this study was to
investigate effects of circuit resistance training at different intensities on HDL-associated
apoM levels in young untrained men.
Methods: Forty-five age- and weight-matched healthy untrained men were
randomly assigned to a control group (n=10) and four training groups: 20% 1-repetition
maximum (1RM) (n=9), 40% 1RM (n=8), 60% 1RM (n=7) and 80% 1RM (n=8). The
subjects performed circuit resistance training consisting of barbell bench press, underarm
flab, seated barbell curl, triceps exercise with chains, lying leg curl, squats, hyperextension,
abs workout, sit-ups and quadriceps workouts (30 seconds each) in three bouts without rest
between stations and with active rest (3 minutes) between sets or bouts. The training
protocol was carried out for 45 minutes per session, three sessions a week, for five weeks.
Venous blood samples were taken 48 hours before the first exercise session and 48 hours
after the last training session. After separating plasma, HDL-associated apoM was measured
using commercial ELISA kits. SPSS 16 was used for analysis of data using two-way ANOVA
and Tukey's post hoc test at significant level of 0.05.
Results: After the training intervention, the exercise groups had higher apoM levels
in total HDL and HDL-2 compared to the control group (P>0.05). However, no significant
difference in HDL-associated apoM level was observed between the study g