Treinamento intervalado de alta intensidade versus treinamento contínuo em pré-diabetes e diabetes tipo 2: revisão sistemática e meta-análise

Abstract

At the beginning of the 21st century, it was estimated that 5.2% of all deaths in the world to diabetes mellitus (DM), which makes this disease the fifth leading cause of death. The prevalence of diabetes has also increased in Brazil, being the country with the fourth largest number of individuals affected by this disease. Physical exercise, recognized as an important tool for the prevention, control and treatment of DM and its complications, is associated with a lower risk of mortality in these individuals. Recently, high-intensity interval training (HIIT) has been an alternative to continuous moderate intensity training (MICT) in different populations, with similar or higher physiological adaptations, showing a time-efficient, safe and well accepted strategy. Although individual studies show greater benefits with HIIT intervention on some metabolic and physiological outcomes, meta-analyzes have concluded that HIIT versus MICT showed no difference in insulin resistance and fasting glucose in subjects with type 2 diabetes (T2D). Thus, the superior effects of HIIT are still controversial and inconclusive on physiological and metabolic outcomes in prediabetes or T2D subjects. In order to summarize and synthesize evidence on the efficacy and effects of HIIT versus MICT on functional capacity, physiological variables, glycemic control, lipid profile and body composition in prediabetes subjects and T2D, our study was characterized as a systematic review and meta-analysis conducted according to the PRISMA. The search strategy was performed in the PubMed (MEDLINE), EMBASE, PEDro, CENTRAL, Scopus, LILACS and Clinical Trials databases to identify literature from inception to July 2017. Two reviewers independently selected studies, extracted data, assessed risk of bias by the Cochrane tool, and evidence of outcomes by classification of recommendation, evaluation, development, and evaluation (GRADE). From 818 potentially relevant records, 7 studies were included in systematic review and 5 in meta-analysis. This review included 64 patients with prediabetes and 120 with T2D. The meta-analysis evidenced that HIIT promoted a significant increase of 3.02 mL/kg/min of VO2max (95% CI 1.42 to 4.61) compared to MICT in T2D. In the other outcomes evaluated, the two modalities of exercise induced similar effects in prediabetes and diabetics. Most of the studies present an uncertain risk of bias, low and very low quality of evidence for the outcomes assessed by GRADE. From this review, it is concluded that HIIT has the potential to be used as a training modality in prediabetes and T2D individuals, with similar effects to MICT in cardiometabolic outcomes and superior on functional capacity. PROSPERO CRD42016047151.