Insulin Dose Adjustments for Meals Differing in Fat Content in T1DM
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 10
- 主要终点
- Glycaemic responses. Assessed via venous blood concentrations at periodic intervals.
研究概览
简要总结
People with Type 1 diabetes (T1DM) are usually provided guidance on how best to control glycaemia around meal times through adjusting their rapid-acting insulin dose according to the carbohydrate content of the meal (e.g. 1 IU per 10/15 g of carbohydrate; Schmidt et al., 2014). However, a potential issue around this method is the role of dietary fat in the calculation of insulin requirements (Wolpert et al., 2013). The fat component of the meal has the potential to influence the insulin dose requirement to normalise postprandial glycaemia (Wolpert et al., 2013). Although normalising postprandial glycaemia is vital, postprandial lipaemia is also an important consideration for long-term health, and at present there is scant data in this area in T1DM. In addition, changing the macronutrient composition of foods and altering insulin doses may carry important implications for vascular function and prospective appetite regulation.
This research will examine the glycaemic and lipaemic responses after consuming a mixed meal similar in carbohydrate content, but differing in fat content. Moreover, this research will assess whether acute postprandial reductions in insulin sensitivity can be offset through increasing the dose of rapid-acting insulin for such meals. Venous blood samples will be collected before and for 6 hours after meals, for the determination of glycaemic and lipaemic responses, as well as metabolite and hormonal parameters. In addition this study will assess the impact of mixed meals and adjusting insulin dose on vascular function and subjective ratings of appetite.
The findings from this study will benefit patients with type 1 diabetes by the provision of more refined self-management strategies for insulin dosage around meal-times.
详细描述
Study design and Methodology General Design: 18 male or female type 1 diabetes (T1DM) individuals aged between 18 and 50 years old will be invited to attend four laboratory sessions, each separated by 7 days. Participants will be recruited in clinic and through advertising in local media. Participants will complete four main trials in a randomised and counter balanced fashion. Main trials will involve the manipulation of both the meal composition (fat content) and rapid-acting insulin dose. During each visit blood samples will be measured over a 6 hour postprandial period to determine glycaemic, lipaemic, hormone, and metabolite parameters.
Sample size calculation:
Sample size requirement was estimated using Eq. 1 Hopkins (2000):
n = 8s2/d2 [Eq. 1] Where n is the sample size, s is the typical error in measurement and d is the meaningful effect size. The magnitude of d was derived from 0.8 of the between subject variation, which was calculated using existing data. The postprandial incremental area under the curve (AUC) for triglyceride concentrations following a mixed-macronutrient meal in people with T1DM is typically 0.74 mmol.l-1.hour-1, with a between-subject standard deviation of 0.99 mmol.l-1.hour-1 (Levetan et al. 2003). Therefore d was calculated as 0.79 mmol.l-1.hour-1. The CV of this measure derived from repeated trials is 23% (Weiss et al. 2008), giving a typical error in the region of 0.18 mmol.l-1.hour-1. These data indicate a sample size of 18 participants provides greater than an 80% chance of detecting a statistically significant effect with a P value of < 0.05.
Inclusion/exclusion criteria Participants: For inclusion in the study, volunteers will be either male or female and aged 18-50 years old, free from any diabetes complications apart from background diabetic retinopathy, not taking any prescribed medication other than insulin, and be treated with a stable insulin regimen composed of a combination of slow/long acting insulin glargine/determir and a fast acting insulin analogue (lispro or aspart, glulisine), and have a HbA1c of <9.5% (80 mmol/mol). Participants will be currently using the carbohydrate counting method for administering meal time rapid-acting insulin.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 否
入选标准
- •For inclusion in the study, volunteers will be -
- •either male or female and aged 18-50 years old
- •free from any diabetes complications apart from background diabetic retinopathy
- •not taking any prescribed medication other than insulin
- •treated with a stable insulin regimen composed of a combination of slow/long acting insulin glargine/determir and a fast acting insulin analogue (lispro or aspart, glulisine)
- •have a HbA1c of <9.5% (80 mmol/mol)
- •using the carbohydrate counting method for administering meal time rapid-acting insulin.
排除标准
- 未提供
研究组 & 干预措施
1
Carbohydrate only meal: Participants will consume a standardised carbohydrate meal (80 g of carbohydrates, 25 g protein, 0 g fat: meal composition, white rice, chicken, curry sauce; 420 kcal) and will self-administer (into the subcutaneous tissue of the abdomen, as per their regular routine) a rapid-acting insulin dose calculated as per the carbohydrate-counting ratio (e.g. 1 IU of insulin per 10 g of carbohydrates).
干预措施: Meal composition (Dietary Supplement)
2
Participants will replicate Trial 1, but on this occasion the meal consumed will have an additional 50 g of fat (via addition of Ghee). This fat will be added to the sauce within the meal (80 g of carbohydrates, 25 g of protein, 50 g of fat; 735 Kcal). Participants will administer their rapid-acting insulin as per the carbohydrate counting method (i.e. the same IU of insulin as per Trial 1).
干预措施: Meal composition (Dietary Supplement)
3
Trial 3) Participants will replicate Trial 2, but will administer a rapid-acting insulin dose that has been increased by 30%.
干预措施: Meal composition (Dietary Supplement)
3
Trial 3) Participants will replicate Trial 2, but will administer a rapid-acting insulin dose that has been increased by 30%.
干预措施: Rapid-Acting Insulin Dose (Drug)
4
Participants will replicate Trial 2, but will administer an additional rapid-acting insulin dose of 30% 3 hrs post-meal.
干预措施: Meal composition (Dietary Supplement)
4
Participants will replicate Trial 2, but will administer an additional rapid-acting insulin dose of 30% 3 hrs post-meal.
干预措施: Rapid-Acting Insulin Dose (Drug)
结局指标
主要结局
Glycaemic responses. Assessed via venous blood concentrations at periodic intervals.
时间窗: 6 hours
次要结局
- Appetite responses. Assessed via subjective visual analogue scales at periodic intervals(6 hours)
- Lipaemic responses. Assessed via venous blood concentrations at periodic intervals.(6 hours)
- Interstitial glucose responses. Assessed using real-time continuous glucose monitoring throughout the duration of the study(24 hours)
- Inflammatory responses. Assessed via venous blood concentrations at periodic intervals.(6 hours)