ECSS Paris 2023: OP-MH01
INTRODUCTION: Type 2 diabetes mellitus is a chronic, progressive metabolic disorder marked by insulin resistance, increased inflammation, and oxidative stress (1). While high-intensity interval training (HIIT) has shown substantial benefits in modulating angiogenesis and flogosis (2), sodium nitrite (NaNO2) supplementation has emerged as a promising agent for enhancing insulin sensitivity and reducing oxidative stress (3). Thus, our study was conducted to elucidate the effects of sodium NaNO2 and HIIT on metabolic and vascular dysfunction biomarkers of subclinical chronic inflammation. METHODS: To this aim diabetic rats, obtained by applying the nicotinamide-streptozotocin method, were used as experimental animal model. An overall sample of 25 male rats was assigned to one of 5 groups: control animals, diabetic animals, diabetic+NaNO2 supplementation, diabetic+HIIT, and diabetic+HIIT+NaNO2 supplementation. Exercise intervention consisted of an 8-week HIIT protocol with increasing intensity and duration, adjusted every 2 weeks based on reassessed maximum running speed. NaNO2 was administered in 3 doses via tail injection (12 nmol/kg each), with a one-week interval among doses. Specific biomarkers (i.e., TNF-alpha, MuRF1, PI3K, Klotho, and Resistin were measured in rat cardiomyocytes by ELISA). One-way ANOVA and Kruskal-Wallis tests were used for between-group comparisons, followed by Dunnett’s T3 and Dunn-Bonferroni post-hoc tests. RESULTS: As compared to control animals, diabetic animals displayed higher MURF-1 and TNF-alpha levels (p=0.047 and p=0.002, respectively), while greater Resistin levels were apparent both in diabetic (p=0.007) and HIIT animals p=0.008). Finally, increased Klotho levels emerged in the NaNO2+HIIT and NaNO2 groups (p=0.001 and p=0.044, respectively) compared to diabetic animals whereas significantly higher PI3K levels were apparent both in control (p<0.001) and NaNO2+HIIT (p=0.017) rats. CONCLUSION: In conclusion our results show that while combined intervention (NaNO2+HIIT) effectively increased both Klotho and PI3K levels, isolated NaNO2 supplementation selectively ameliorated Klotho levels at the cardiomyocyte level of diabetic rats. When administered alone, HIIT was not effective in contrasting diabetes-induced alterations in inflammatory and metabolic biomarkers in an experimental diabetic animal model. References: (1) Lu X, et al. Type 2 diabetes mellitus in adults: pathogenesis, prevention and therapy. Signal Transduct Target Ther. 2024 Oct 2;9(1):262 (2) Magalhães FDC, et al. High-intensity interval training followed by postexercise cold-water immersion does not alter angiogenic circulating cells, but increases circulating endothelial cells. Appl Physiol Nutr Metab. 2020 Jan;45(1):101–11 (3) Hughan KS,et al. Oral Sodium Nitrite Improves Insulin Sensitivity, Blood Pressure, and Arterial Thickening in Adults with Uncontrolled Hypertension and Metabolic Syndrome. Diabetes. 2018 Jul 1;67(S_1):75
Read CV SAMANEH EFTEKHARIRANJBARECSS Paris 2023: OP-MH01
INTRODUCTION: Time-restricted eating (TRE) and high-intensity interval training (HIIT) have emerged as two promising alternatives to the current diet and physical activity recommendations for improving cardiometabolic health. In our previous study, 7 weeks of TRE combined with supervised HIIT (TREHIIT) reduced fat mass, visceral fat, and HbA1c and improved cardiorespiratory fitness (CRF) in women with overweight/obesity (1). The effects of TREHIIT in free-living conditions with minimal follow-up remain unclear. We investigated the effects of a digitally monitored TREHIIT intervention completed outside the laboratory on fat mass and secondary cardiometabolic health outcomes in men and women with overweight/obesity. METHODS: We randomized 52 adults (50% female, 37.5 ± 6.9 years, body mass index (BMI) 33.0 ± 4.1 kg/m2) 1:1 to a 7-week TREHIIT intervention or a control group (CON). The intervention included 3 weekly HIIT sessions performed as the participants’ preferred aerobic activity at ≥ 90% maximal heart rate, and a ≤ 10-h/day TRE window with ad libitum energy intake. All HIIT sessions were performed in free-living conditions after one supervised introductory session. Participants in TREHIIT received one weekly follow-up via telephone. Participants in CON received no intervention nor weekly follow-up. The primary outcome was fat mass change. We measured secondary body composition outcomes, CRF, and cardiometabolic health markers in fasting blood samples. We analyzed between-group differences using linear mixed models and considered p <.01 statistically significant for secondary outcomes. RESULTS: Forty-two participants completed the study. We found no statistically significant difference in fat mass (-1.0 kg, 95%CI -2.3 to 0.4, p=.146). Participants in TREHIIT had reduced body mass (-2.1 kg, 95%CI -3.4 to -0.8, p=.002) and tendencies of reduced muscle mass (-0.7 kg, 95%CI -1.3 to -0.2, p =.013). CRF, measured as absolute and relative peak oxygen uptake, increased after TREHIIT (0.4 L/min, 95%CI 0.1 to 0.6, p=.008 and 3.4 mL/min/kg, 95%CI: 0.9 to 5.9, p=.010, respectively). There were no statistically significant between-group differences in remaining secondary outcomes. CONCLUSION: TREHIIT in a real-world setting with digital follow-up did not reduce fat mass among adults with overweight/obesity. However, CRF significantly increased after TREHIIT, and the improvement was similar to that observed in our previous study of 7 weeks supervised TREHIIT. These findings suggest that a thrice weekly HIIT intervention is feasible without extensive supervision and can induce important improvements in cardiovascular health, but additional support may be required for effective fat mass reduction. Reference 1. Haganes KL, Silva CP, Eyjólfsdóttir SK, Steen S, Grindberg M, Lydersen S, et al. Time-restricted eating and exercise training improve HbA1c and body composition in women with overweight/obesity: A randomized controlled trial. Cell Metabolism. 2022;34(10):1457-71.e4.
Read CV Kamilla La HaganesECSS Paris 2023: OP-MH01
INTRODUCTION: Preservation of lean mass is critical to maintain good health, especially in individuals with obesity. In the obese population, the loss of lean mass can lead to sarcopenic obesity and impose significant detriment in functional independence, quality of life, and even the management of obesity and its comorbid conditions, such as diabetes. Although resistance training is well-established as an exercise strategy to mitigate the loss of lean mass, its implementation at the public health level is limited due to barriers such as access to equipment and knowledge on how to perform the movements correctly. High-intensity interval training (HIIT) is a popular exercise strategy in the general and obese population with robust benefits on cardiorespiratory and adiposity health. However, its effects on lean mass are inconclusive, as evidence in the literature is mainly derived from studies employing cycling HIIT with small sample sizes (e.g., 10 participants per group). Thus, limiting its interpretation and application to the broader community. This study presents the secondary findings of a randomized controlled trial that examined the effects of once-weekly and thrice-weekly walking/jogging HIIT on lean mass in adults with central obesity. METHODS: In this three-arm, assessor-blinded, randomized controlled trial, 315 adults (Age: 48±13; BMI: 28.7±3.8) with central obesity (waist circumference ≥80cm for women and ≥90cm for men) were randomized in a 1:1:1 ratio to once-weekly HIIT (H1: n=105), thrice-weekly HIIT (H3: n=105) and usual care (CON: n=105). Usual care participants attended a 150-minute health education class every 2 weeks for 16 weeks. HIIT participants received 75 minutes of supervised HIIT per week for 16 weeks. Training was conducted on a treadmill using the 4×4-min protocol, which consists of four 4-min intervals at 85-95% peak heart rate with a 3-min active recovery between each interval. Outcome assessments were conducted before and after the 16-week intervention. Appendicular lean mass (ALM), lower limb lean mass (LLM) and upper limb lean mass (ULM) was assessed using dual-energy x-ray absorptiometry. Generalized estimating equations was used to assess the treatment effects, with baseline values used as covariates. RESULTS: After 16 weeks of intervention, ALM, LLM and ULM was significantly greater in the once-weekly (ALM: H1 vs CON: +0.58kg; P<0.0001) and thrice-weekly HIIT group (ALM: H3 vs CON: +0.66kg; P<0.0001) compared to the CON group. No significant difference was found between once-weekly and thrice-weekly HIIT for all outcomes (ALM: H3 vs H1: +0.08kg; P=0.49). CONCLUSION: Walking/jogging HIIT performed for 75 minutes a week (regardless of once-weekly or thrice-weekly) can induce modest improvements in lean mass relative to control in adults with central obesity. These findings enhance the role of HIIT as a public health exercise strategy to provide holistic health benefits ranging from cardiorespiratory health to lean mass.
Read CV Chit Kay LeungECSS Paris 2023: OP-MH01