Randomized Controlled Trial of Vitamin D Supplementation on Glucose Metabolism in Subjects With Components of the Metabolic Syndrome
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 73
- 试验地点
- 2
- 主要终点
- Insulin sensitivity
研究概览
简要总结
Vitamin D deficiency is widespread throughout the world, and the deficiency has been associated with several chronic diseases, such as cardiovascular diseases and diabetes. In Nordic countries, like in Finland, there is a particular variation in vitamin D status, and during wintertime, when there is no exposure to ultraviolet-B light from the sun, serum concentrations of vitamin D decrease substantially. In Finland, some 40% of middle-aged men and one third of women also have some degree of impairment of glucose metabolism.
The purpose of this trial is to investigate the effects of two different daily doses of vitamin D on glucose metabolism in men 60 years of age or older and who are vitamin D deficient, have a high body mass index and at least two characteristics of cardio-metabolic syndrome.
Altogether 102 subjects with low serum calcidiol (<60 nmol/L) will be recruited and randomized to one of the three groups: 1) 40 µg/d vitamin D3, 2) 80 µg/d vitamin D3 or 3) placebo. The supplementation period will last for 6 months from September 2011 to March 2012.
The main hypotheses of the trial are: (1.) Vitamin D supplementation will improve glucose and insulin metabolism in people with a low baseline vitamin D status, in a dose-dependent manner. (2.) Vitamin D supplementation will have an effect on the expression of genes involved in glucose and insulin metabolism and inflammation. (3.) Vitamin D supplementation will have an effect on epigenetic changes in key genes participating in vitamin D metabolism.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 60 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age 60 years or older
- •Serum calcidiol <75 nmol/L
- •Body mass index 25-35 kg/m2
- •Impaired fasting glucose or impaired glucose tolerance (fasting glucose 5.6-7.0 mmol/L or 2h oral glucose tolerance test glucose 7.8-11.0 mmol/L)
排除标准
- •Any chronic disease and condition, which may hamper to follow the intervention protocol (such as alcohol abuse)
- •Any chronic disease or therapy which may mask or interact with the investigated effects (such as diabetes or systemic corticosteroid therapy)
- •Any disease or state that raises a vitamin D related safety concern (such as chronic liver, thyroid or kidney disease, hypercalcemia, sarcoidosis or other granulomatous diseases such as active chronic tuberculosis or Wegener's granulomatosis)
- •Use of supplements yielding vitamin D over 20 µg/d and unwillingness to discontinue the use.
结局指标
主要结局
Insulin sensitivity
时间窗: Six months
Change in insulin sensitivity measured by oral glucose tolerance test at baseline and after 6 months
次要结局
- Peripheral blood mononuclear cell gene expression(Six months)
- Inflammation(Baseline to six months)
- Adipose tissue gene expression(Six months)
研究者
Tomi-Pekka Tuomainen
Professor
University of Eastern Finland