School of Public Health, Xinhua Hospital, Shanghai Jiao Tong University, Shanghai, 200025, China.
Global Health Institute, School of Public Health, Xi'an Jiaotong University Health Science Center, 76 Yanta West Road, Xi'an, Shaanxi, 710061, China.
Trials. 2021 Dec 6;22(1):888. doi: 10.1186/s13063-021-05861-x.
Although approximately 50% of Chinese with type 2 diabetes mellitus (T2DM) patients have vitamin D deficiency, studies regarding vitamin D supplementation on insulin resistance (IR) have mainly focused on non-Asians. Endurance exercise training (ET) enhances insulin-mediated glucose metabolism, which plays a critical role in T2DM prevention and control. However, the combined effects of vitamin D supplementation and ET on IR in T2DM patients are unclear. The objectives of this study is to investigate the synergistic effect of vitamin D supplementation combined with exercise training intervention on IR in T2DM patients.
We propose a 3-month randomized controlled trial among 60 T2DM patients aged 40-65, newly diagnosed with T2DM ≤ 1 year, and with stable HbA1c level (≤ 8.0%) in the past 3 months. The participants will be randomly allocated to the vitamin D group, vitamin D combined with exercise training group, exercise training group, and control group (CG) using a computer-generated random number sequence. At baseline, participants will undergo a medical review, anthropometric measurements, dual X-ray absorptiometry, a 75-g oral glucose tolerance test (OGTT), ankle-brachial index measurements, and physical fitness measurements and will complete related lifestyle questionnaires. Fasting blood lipid and glucose levels were also measured. In a 3-month intervention period, vitamin D intervention group will receive a dose of 1000 IU daily; exercise group will perform a 1-h endurance exercise 3 times per week (maximal heart rate, 60-80%), and the control group will receive apparently identical tablets. Additionally, all participants will be advised to maintain their normal diet and physical activities during the intervention. All measurements will be repeated at 3-month follow-up after the intervention with the primary outcome measure expressed as a change from baseline in insulin sensitivity and secretion. Secondary outcome measures will compare the changes in anthropometry, ankle-brachial index, and physical fitness factors (e.g., peak oxygen uptake, hand grip strength). Data will be managed and analyzed using the Statistical Package for the Social Sciences.
This is the first study to conduct a randomized trial to clearly determine the independent and combined effects of vitamin D supplementation and endurance exercise trial on IR in Chinese T2DM patients as measured by OGTT. The findings from the proposed study will not only provide new evidences that vitamin D supplementation plays an important role in IR management but also develop a simple and efficient method to improve IR-associated metabolic diseases for T2DM patients.
Chinese Clinical Trial Registry ChiCTR1800015383 , Registered on 28 March 2018.
尽管约有 50%的中国 2 型糖尿病（T2DM）患者存在维生素 D 缺乏，但关于维生素 D 补充对胰岛素抵抗（IR）影响的研究主要集中在非亚洲人群。耐力运动训练（ET）可增强胰岛素介导的葡萄糖代谢，这在 T2DM 的预防和控制中起着至关重要的作用。然而，维生素 D 补充和 ET 联合应用对 T2DM 患者 IR 的影响尚不清楚。本研究旨在探讨维生素 D 补充联合运动训练干预对 T2DM 患者 IR 的协同作用。
我们拟对 60 例年龄在 40-65 岁、新诊断的 T2DM 患者（病程不超过 1 年）进行一项为期 3 个月的随机对照试验，所有患者的 HbA1c 水平在过去 3 个月内稳定（≤8.0%）。采用计算机生成的随机数序列将参与者随机分为维生素 D 组、维生素 D 联合运动训练组、运动训练组和对照组（CG）。在基线时，参与者将接受医学检查、人体测量、双能 X 线吸收法、75g 口服葡萄糖耐量试验（OGTT）、踝肱指数测量以及体能测量，并完成相关生活方式问卷。还检测了空腹血脂和血糖水平。在 3 个月的干预期间，维生素 D 干预组每天接受 1000IU 的剂量；运动组每周进行 3 次 1 小时的耐力运动（最大心率 60-80%），对照组则接受表面上相同的片剂。此外，所有参与者在干预期间均被建议保持正常饮食和身体活动。干预后 3 个月的随访时，将对主要结局指标（胰岛素敏感性和分泌的变化）进行重复测量。次要结局指标将比较人体测量学、踝肱指数和身体成分（如最大摄氧量、握力）的变化。数据将使用社会科学统计软件进行管理和分析。
这是第一项进行随机试验以明确确定维生素 D 补充和耐力运动试验对中国 T2DM 患者 OGTT 测量的 IR 的独立和联合作用的研究。该研究的结果不仅将提供新的证据，证明维生素 D 补充在 IR 管理中起着重要作用，而且还将为 T2DM 患者开发一种简单有效的改善与 IR 相关的代谢性疾病的方法。
中国临床试验注册中心 ChiCTR1800015383 ，于 2018 年 3 月 28 日注册。
