Avaliação do efeito de um programa combinado de exercícios de hipertrofia muscular e aeróbio na composição corporal, força muscular, marcadores bioquímicos e tecido ósseo de obesos submetidos a cirurgia bariátrica

Abstract

Bariatric surgery has been frequently used as an alternative for treatment of obesity. However, the patients undergoing this type of procedure have changes in body composition and bone metabolism. The objective of this study was to assess the impact of a supervised muscular hypertrophy and aerobic combined exercises program in body composition, muscular force, biochemical markers and bone mass in individuals submitted to bariatric surgery. The sample consisted in 37 obese subjects (81.1% female, mean age=38.2 ± 11.1, BMI=42.4 ± 3.7 Kg/m2) submitted to bariatric surgery and follow-up one year after Roux-en-Y gastric bypass surgery. The whole body densitometry (DXA) was used to evaluate the body mineral density (BMD), total body fat and lean body mass in pre and postoperative. Laboratory investigations consisted of serum calcium, PTH, 25-hydroxyvitamin D and bone remodeling markers (Ctelopeptide of collagen type I- CTX and bone specific alkaline phosphatase - BAP). Muscle strength was determined by concentric 10 repetition maximum test (10RM) and hand grip dynamometer (JAMAR®), 3 measures being carried out in each hand, alternately, and choose the highest value obtained during the measurements. In the same period were performed the vertical displacement test to evaluate aláctica anaerobic power. The test consists of climbing a staircase of 13 steps of 15.8 cm each, at the highest possible speed, and measured the test execution time and subsequently calculated the PAA. Postoperatively, subjects were divided into two groups: training group (TG) - 18 volunteers who participated in a supervised exercise program of muscle strengthening, two nonconsecutive days per week, during 35 weeks. Each session lasted 90 minutes and included eight exercises for muscular hypertrophy: seated chess press, lat pull down, standing biceps curl, standing triceps extension, fly machine, leg extension, leg press and leg curl, that have been prescribed 1-3 sets of 10-12 repetitions an intensity that was determined by 10RM test for each exercise. After these trainning 25 minuts o aerobic exercises were performed n a treadmill or cycle ergometer at intensity of 60-80% heart rate (HR) maximum for his age. The control group (CG) consisted of 19 volunteers who were not part of the exercise program. The TG was reevaluated every 06 weeks for the test of strength and displacement and the GC every 04 months follow-up. Blood tests were repeated for all volunteers with 02, 09 and 12 months postoperatively. Statistical analysis were done by Student's t-test and ANOVA for repeated measures with post hoc by Bonferroni, with a significance level of 5% (p <0.05). The results showed that the TG and CG presented significant reductions in weight at the end of the first year of surgery (109.88 ± 11.39 vs 73.6 ± 8.1 Kg e 108.8 ± 9.9 vs 77.5 ± 11.9 Kg, respectively), but without significant differences between groups (p>0,05). There was no significant difference between groups in relation to bone markers or calcium metabolism. After one year, TG showed smaller decreases in total BMD (0.07 ± 0.049 vs 0.140± 0.081 g/cm3, respectively); bone mass at the spine (1.19 ± 0.13 vs 1.13 ± 0.14g/cm3) and right lower limb (RLL) (1.26 ± 0.04 vs 1.22 ± 0.14g/cm3) when it was compared with CG (p<0.05). In body composition, the GT had lowest mass reduction (Kg) than the GC (2.17 ± 3.60 vs 4.8 ± 2.22 kg, p <0.05). Furthermore, TG had a significant increase in arms lean mass relative to CG (66.17 ± 7.5 vs 63.6 ± 8.1 %; p<0.05). The overall strength measure by hand grip dynamometer and specific muscle strength analized by 10RM test was statistically greater in the TG compared with CG at the end of one year postoperative (36.0±8.9 vs 31.0±8.0 Kgf; p<0.05). TG showed statistically superior results to the time between the vertical displacement test compared to the CG at the end of follow-up (3.28 ± 0.5 vs 3.8 ± 0.7 seconds respectively; p> 0.05) . The PAA values were not statistically different between groups (p <0.05). This study demonstrated that supervised muscular hypertrophy and aerobic combined exercises program did not influence bone remodeling markers, but attenuated spine and RLL bone loss and improved muscle mass in the arms and the overall muscle strength of the study population.