Effectiveness of resistance exercise compared to aerobic exercise without insulin therapy in patients with type 2 diabetes mellitus: a meta-analysis.

BACKGROUND: Physical exercise has been used to mitigate the metabolic effects of diabetes mellitus. OBJECTIVE: To evaluate the effect of resistance exercise when compared to aerobic exercise without insulin therapy on metabolic and clinical outcomes in patients with type 2 diabetes mellitus. METHODS: Papers were searched on the databases MEDLINE/PubMed, CINAHL, SPORTDiscus, LILACS, and SCIELO, without language or date of publication limits. Clinical trials that compared resistance exercise to aerobic exercise in adults with type 2 diabetes mellitus who did not use insulin therapy were included. The quality of evidence and risk of bias were assessed using the GRADE system and the Cochrane Risk of Bias tool, respectively. Meta-analysis was also used, whenever possible. Two reviewers extracted the data independently. Eight eligible articles were included in this study, with a total of 336 individuals, with a mean age of 48-58 years. The protocols of aerobic and resistance exercise varied in duration from eight to 22 weeks, 30-60min/day, three to five times/week. RESULTS: Overall the available evidence came from a very low quality of evidence and there was an increase in Maximal oxygen consumption (mean difference: -2.86; 95% CI: -3.90 to -1.81; random effect) for the resistance exercise and no difference was found in Glycated hemoglobin, Body mass index, High-density lipoprotein cholesterol, Low-density lipoprotein cholesterol, triglycerides, and total cholesterol. CONCLUSIONS: Resistance exercise appears to be more effective in promoting an increase in Maximal oxygen consumption in protocols longer than 12 weeks and there is no difference in the control of glycemic and lipid levels between the two types of exercise.

Regenerative capacity and histomorphometric changes in rat sciatic nerve following experimental neurotmesis / Capacidad regenerativa y cambios histomorfométricos en el nervio ciático de ratas luego de una neurotmesis experimental

Through a wide range of cellular and molecular events, the peripheral nervous system is endowed with great regenerative capacity, responding immediately to injuries that occur along the length of the nerve. The aim of this study was to histomorphometrically assess the degree of maturity of the nervous tissue and possible microscopic changes in newly formed nerve segments 60 days after experimental neurotmesis of the sciatic nerve in rats. Control Group (CG) and an Injury Group (IG) were used. IG underwent neurotmesis of the sciatic nerve of the right foot, with immediate surgical repair using the tubulization technique. 60 days following experimental surgery, animals from both groups had their sciatic nerves collected for histomorphometric analysis. Statistical analysis was performed, using the Student t-test for independent samples, expressed as mean ± standard deviation, with 5% significance. In the event of injury, peripheral nerve tissue is mobilized in an intrinsic self-healing process. 60 days following of nerve regeneration in neurotmesis injury, the peripheral nerve presents a segment joining the newly formed neural stump. The new stump has a number of regenerated axons compatible with an intact nerve, but which still show great immaturity in the axonal structural layers of the nerve.

Mediante diversos procesos celulares y moleculares, el sistema nervioso periférico tiene una gran capacidad regenerativa, respondiendo inmediatamente a las lesiones ocurridas a lo largo de su extensión. El objetivo de este estudio fue evaluar histomorfométricamente el grado de madurez del tejido nervioso y los posibles cambios microscópicos en los segmentos nerviosos recién formados 60 días después de la neurotmesis experimental en el nervio ciático de ratas. Se utilizaron 9 ratas (Wistar) separadas en grupo control (GC, n= 4) y Grupo lesión (GL, n= 5). A los 60 días de vida, el grupo GL fue sometido a neurotmesis del nervio ciático de la miembro posterior derecho, con inmediata corección quirúrgica con la técnica de tubolización. Completados 60 días luego de la cirugía experimental, los animales de ambos grupos fueron anestesiados y sus nervios ciáticos seccionados para el análisis histomorfométrico. Se realizó un análisis estadístico utilizando la prueba t de Student para muestras independientes, expresado como media ± desviación estándar, con un 5% de significancia. A los 60 días de la lesión por neurotmesis, el nervio ciático del GL presentó alteraciones histomorfométricas significativas para las variables: número de vasa nevorum, densidad de fibras mielínicas, diámetro axonal y de fibras mielínicas, espesor de la vaina de mielina y razón G, con similitud solamente para los números absolutos de fibras mielínicas regeneradas. El nervio periférico durante su proceso regenerativo, pasa por grandes alteraciones estructurales, siguiendo una secuencia coordinada de acciones, que dependiendo de las condiciones del microambiente donde ocurre esta regeneración, podrá ser clave para el nivel de regenerecion nerviosa periférica.

Aerobic physical training restores biomechanical properties of Achilles tendon in rats chemically induced to diabetes mellitus.

UNLABELLED: The aim of this study is to evaluate if the application of a moderate aerobic exercise protocol reverses the damage caused by diabetes on the mechanical properties of the Achilles tendon. METHODS: Forty-four rats were divided randomly into four groups as follows: Sedentary Control Group-SCG, Sedentary Diabetic Group-SDG, Trained Control Group-TCG and Trained Diabetic Group-TDG, the trained groups were submitted to a protocol of moderate physical training on a continuous treadmill. For mechanical testing the tendons were fixed in a conventional mechanical testing machine and pulled to the point of failure of the specimen, the cell load of 500N. The parameters were: Elastic Modulus (MPa), Stress Maximum Strength (MPa), Strain Specific Maximum Force (mm), Energy / Tendon Area (N.mm/mm(2)) and Cross-sectional Area (mm(2)). RESULTS: The evaluation of the biomechanical properties of the Achilles tendon of the SDG indicated that the elastic modulus (MPa) is decreased when compared to the TDG and the other groups (p<0.01). However, the specific deformation (%), the deformation at maximum force (mm), and energy / tendon area (N.mm/mm(2)) of the SDG were significantly higher than in the other groups (p<0.01). Moreover, moderate aerobic training on a treadmill caused the biomechanical property values to move closer to the values shown by the control groups (p>0.01). CONCLUSION: In summary, our study indicates that moderate-intensity aerobic training restored the normal mechanical properties of tendons in diabetic animals, since the elastic modulus (MPa), the specific deformation (%), the deformation of the maximum force (mm) and energy / tendon area (N.mm/mm(2)) approached the values shown by the control groups.