INHIBITORY CONTROL, RESPONSE TIME, PLASMA BDNF CONCENTRATIONS AFTER A AEROBIC AND RESISTANCE EXERCISE BOUT IN MIDDLE-AGED AND OLDER ADULTS WITH TYPE 2 DIABETES
Description
This pilot study took part in a controlled clinical trial registry in the Brazilian Registry of Clinical Trial (register no. RBR86hfz5, WHO international clinical trials registry platform no. U1111-1202-6942). Sample characteristics Eleven physically active middle-aged and older adults (9 post-menopausal women/ 2 men) with a physician diagnosis of T2DM following American Diabetes Association criteria were recruited between September and October/17. Experimental design In the within-subject counterbalanced trial, four visits were programmed to answer the research questions (Figure 1). The first visit was designed to baseline blood samples and cognitive screening. The second visit was intended for anthropometric measures, familiarisation with cognitive tasks, and physical testing to determine the intensity of exercise sessions. Then, at the subsequent two visits, the AER (aerobic exercise) and RES (resistance exercise) situations were performed in a counterbalanced design. Before and immediately after each exercise session, we evaluated cognitive tasks and collected blood samples. Physical testing and exercise protocol The exercise protocols were planned according to the recommendations of the American Diabetes Association for aerobic and resistance exercise in T2DM subjects (Kanaley et al. 2022). Exercise protocols were not energy expenditure matched and were designed to support a greater ecological validity. These 40-minute exercise sessions were interspaced by 72 h and occurred between 2:00 and 4:00 PM. The AER exercise intensity was determined by the six-minute walk test (6MWT). In 6MWT, participants should walk at maximal speed for six minutes in a 30-meter indoor room (Rikli and Jones 2013). In AER, participants should walk at 90-95% of the speed obtained in 6MWT. The RES exercise intensity was determined by 10-Repetition Maximum Test (10RM) following the 10-RM protocol guidelines (Baechle, Thomas R.; Earle, Roger 2008). In RES, participants performed eight strength exercises for upper and lower limbs (leg press, bench press, calf raises, front pulldown, knee extension machine, dumbbell shoulder press, wide-grip inclined cable row, and abdominal crunches). The subjects performed three sets of ten repetitions in each exercise, at 70% of 10-RM and 60 seconds of rest between sets. Plasma BDNF concentrations Pre- and post-exercise blood samples were collected in EDTA tubes during the fed state and at the same hour (2-3 PM or 3-4 PM) to measure plasma BDNF concentrations. After collection and plasma separation (10 min, 3500rpm, and 4°C), samples were stored at -80° C until further BDNF determination using sandwich enzyme-linked immunosorbent assay (ELISA) with a commercial kit (DY248 DuoSet, R&D Systems™, MN, USA). Samples were diluted at 1:64 to fit the standard curve range (detection range: 23-1500 pg/ml).