Ramos Joyce S, Dalleck Lance C, Borrani Fabio, Mallard Alistair R, Clark Bronwyn, Keating Shelley E, Fassett Robert G, Coombes Jeff S
Centre for Research on Exercise, Physical Activity and Health, School of Human Movement and Nutrition Sciences, The University of Queensland, Blair Drive, St Lucia, QLD, Australia.
Recreation, Exercise, and Sport Science Department, Western State Colorado University, Gunnison, CO, USA.
Diabetologia. 2016 Nov;59(11):2308-2320. doi: 10.1007/s00125-016-4064-7. Epub 2016 Aug 1.
AIMS/HYPOTHESIS: The continuous demand for insulin in the face of insulin resistance, coupled with the glucolipotoxic environment associated with the metabolic syndrome (MetS), adversely affects the quality of insulin produced and secreted by the pancreatic beta cells. This is depicted by increased circulating intact proinsulin concentration, which is associated with increased MetS severity and risk of cardiovascular (CV) mortality. High-intensity interval training (HIIT) has been shown to reduce insulin resistance and other CV disease risk factors to a greater degree than moderate-intensity continuous training (MICT). We therefore aimed to investigate the impact of MICT and different volumes of HIIT on circulating intact proinsulin concentration.
This was a substudy of the 'Exercise in prevention of Metabolic Syndrome' (EX-MET) multicentre trial. Sixty-six individuals with MetS were randomised to 16 weeks of: (1) MICT (n = 21, 30 min at 60-70% peak heart rate [HRpeak], five times/week); (2) 4HIIT (n = 22, 4 × 4 min bouts at 85-95% HRpeak, interspersed with 3 min of active recovery at 50-70% HRpeak, three times/week); or (3) 1HIIT (n = 23, 1 × 4 min bout at 85-95% HRpeak, three times/week). A subanalysis investigated the differential impact of these training programmes on intact proinsulin concentration in MetS individuals with type 2 diabetes (MICT, n = 6; 4HIIT, n = 9; 1HIIT, n = 12) and without type 2 diabetes (MICT, n = 15; 4HIIT, n = 13; 1HIIT, n = 11). Intact proinsulin, insulin and C-peptide concentrations were measured in duplicate via ELISA, following a 12 h fast, before and after the exercise programme. Fasting intact proinsulin concentration was also expressed relative to insulin and C-peptide concentrations.
Following the exercise training, there were no significant (p > 0.05) changes in fasting intact proinsulin concentration indices in all participants (pre- vs post-programme proinsulin, proinsulin:insulin, proinsulin:C-peptide: MICT 19% decrease, 6% increase, 4% increase; 4HIIT 19% decrease, 8% decrease, 11% decrease; 1HIIT 34% increase, 49% increase, 36% increase). In participants who did not have type 2 diabetes, only 4HIIT significantly (p < 0.05) reduced fasting intact proinsulin concentration indices from pre to post intervention (pre- vs post-programme proinsulin, proinsulin:insulin, proinsulin:C-peptide: 4HIIT 32% decrease, 26% decrease, 32% decrease, p < 0.05; 1HIIT, 14% increase, 32% increase, 16% increase, p > 0.05; MICT 27% decrease, 17% decrease, 11% decrease), with a group × time interaction effect, indicating a greater reduction in intact proinsulin indices following 4HIIT compared with MICT and 1HIIT. There were no significant (p > 0.05) changes in intact proinsulin concentration indices in participants with type 2 diabetes.
CONCLUSIONS/INTERPRETATION: Higher-volume HIIT (4HIIT) improved insulin quality in MetS participants without type 2 diabetes.
ClinicalTrials.gov NCT01676870 FUNDING: The study was funded by the Norwegian University of Science and Technology and from an unrestricted research grant from the Coca-Cola company. Funding for the collection of physical activity data was derived from a 'UQ New Staff Start Up' grant awarded to B. Clark.
目的/假设：面对胰岛素抵抗时对胰岛素的持续需求，再加上与代谢综合征（MetS）相关的糖脂毒性环境，会对胰腺β细胞产生和分泌的胰岛素质量产生不利影响。循环中完整胰岛素原浓度升高就表明了这一点，它与MetS严重程度增加及心血管（CV）死亡风险相关。高强度间歇训练（HIIT）已被证明比中等强度持续训练（MICT）能更大程度地降低胰岛素抵抗和其他CV疾病风险因素。因此，我们旨在研究MICT和不同运动量的HIIT对循环中完整胰岛素原浓度的影响。
这是“运动预防代谢综合征”（EX-MET）多中心试验的一项子研究。66名患有MetS的个体被随机分为三组，进行为期16周的训练：（1）MICT组（n = 21，以60 - 70%心率峰值[HRpeak]运动30分钟，每周5次）；（2）4HIIT组（n = 22，以85 - 95% HRpeak进行4次4分钟的训练，每次训练间穿插3分钟50 - 70% HRpeak的主动恢复，每周3次）；或（3）1HIIT组（n = 23，以85 - 95% HRpeak进行1次4分钟的训练，每周3次）。一项亚分析研究了这些训练方案对患有2型糖尿病（MICT组，n = 6；4HIIT组，n = 9；1HIIT组，n = 12）和未患2型糖尿病（MICT组，n = 15；4HIIT组，n = 13；1HIIT组，n = 11）的MetS个体中完整胰岛素原浓度的不同影响。在运动计划前后，经过12小时禁食后，通过ELISA法对完整胰岛素原、胰岛素和C肽浓度进行双份测定。空腹完整胰岛素原浓度也相对于胰岛素和C肽浓度进行表达。
运动训练后，所有参与者的空腹完整胰岛素原浓度指标均无显著（p > 0.05）变化（训练前与训练后胰岛素原、胰岛素原：胰岛素、胰岛素原：C肽：MICT组分别下降19%、上升6%、上升4%；4HIIT组分别下降19%、下降8%、下降11%；1HIIT组分别上升34%、上升49%、上升36%）。在未患2型糖尿病的参与者中，只有4HIIT组在干预前后显著（p < 0.05）降低了空腹完整胰岛素原浓度指标（训练前与训练后胰岛素原、胰岛素原：胰岛素、胰岛素原：C肽：4HIIT组分别下降32%、下降26%、下降32%，p < 0.05；1HIIT组分别上升14%、上升32%、上升16%，p > 0.05；MICT组分别下降27%、下降17%﹑下降11%）且存在组×时间交互效应，表明4HIIT组相比MICT组和1HIIT组能更大程度降低完整胰岛素原指标。患有2型糖尿病的参与者的完整胰岛素原浓度指标无显著（p > 0.05）变化。
结论/解读：较高运动量的HIIT（4HIIT）改善了未患2型糖尿病的MetS参与者的胰岛素质量。
ClinicalTrials.gov NCT01676870
该研究由挪威科技大学以及可口可乐公司的一项无限制研究资助提供资金。身体活动数据收集的资金来自授予B. Clark的一项“昆士兰大学新员工启动”资助。
