'Low-salt' Bread as Part of a Pragmatic Reduced-salt Diet for Lowering Blood Pressure in Adults With Elevated Blood Pressure
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 97
- 试验地点
- 1
- 主要终点
- Systolic blood pressure at end of intervention periods
研究概览
简要总结
In the context of public health, reformulation of bread in terms of salt content remains an important measure to help achieve a reduction in salt intake in the population. Therefore, the aim of this study was to examine, using a 5-week cross-over design, food-based intervention trial, the potential for inclusion of 'low-salt' bread as part of a pragmatic reduced-salt diet on blood pressure (BP) in adults with slightly to moderately elevated BP.
The study consisted of a randomized crossover trial of the effect of reduced-salt intake or usual-salt intake for 5 weeks on BP (as the primary outcome) in adults with slightly to moderately elevated BP (seated office systolic BP >120 and <160 mmHg or a diastolic BP >80 and <95 mmHg; identified by a pre-screening phase).
Subjects were randomly assigned to the reduced-salt diet or their usual-salt diet (control) for 5 weeks, followed by crossover to the alternative dietary regimen for a further 5 weeks. Subjects randomized to start on the reduced-salt diet were asked to restrict their consumption of dietary salt using a combination of pragmatic dietary advice as well as the replacement of bread and a limited number of other foods with equivalent foods which had lower salt content; these were provided to the participants. At the beginning of the salt restriction period, a research nutritionist provided the subjects with a list of the common salt-containing food and were asked to limit the consumption of such, as feasible. The subjects received in-house prepared 'low-salt (<0.3 g/100 g)' brown or white sliced pan bread as well as no-salt margarine/butter, and were given luncheon meats with no added salt, if desired (optional); these were supplied regularly by the research staff. Subjects commencing the trial on the control diet were allowed to follow their usual diet but were asked to consume an in-house produced brown or white sliced pan bread equivalent in composition to the low-salt version but with its more typical salt content (1.2 g/100 g).
Participants met the research staff weekly to receive breads and no-salt margarine/butter as well as luncheon meats (where applicable), and at these meetings the staff promoted compliance with the intervention and encouraged completion of the study protocol.
BP and other assessments were made at baseline and at the end of week 5 and week 10.
详细描述
Brief background and context for the study:
The World Health Organization's Global Action Plan for the Prevention and Control of Non-Communicable Disease includes a voluntary global target of a 30% relative reduction in mean population intake of salt/sodium by 2025. Bread and cured/processed meats collectively contribute anything from about a third upwards of total salt intake of adults in many Western countries. Reformulation of bread in terms of salt content remains an important measure to help achieve a reduction in salt intake in the population. Therefore, the aim of this study was to examine, using a 5-week cross-over design, food-based intervention trial, the potential for inclusion of 'low-salt' bread as part of a pragmatic reduced-salt diet on blood pressure (BP) in adults with slightly to moderately elevated BP.
Design:
The study consisted of a randomized crossover trial of the effect of reduced-salt intake or usual-salt intake for 5 weeks on BP (primary outcome) and biochemical markers of calcium and bone metabolism as well as plasma lipids (secondary outcomes) in adults with slightly to moderately elevated BP.
Potential volunteers were screened for BP over 3 weeks preceding the intervention phase of the trial during which seated office systolic and diastolic BP were measured weekly and those with systolic BP >120 and <160 mmHg or a diastolic BP >80 and <95 mmHg were considered eligible.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Prevention
- 盲法
- Single (Outcomes Assessor)
盲法说明
The biochemical outcome measures were assessed by researchers masked to the phase of the cross-over intervention from which the samples were derived.
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •consenting adult Caucasian men and women, aged ≤65 y;
- •a seated office systolic BP >120 and <160 mmHg and/or a diastolic BP >80 and <95 mmHg (based on the mean BP across 3 screening visits as part of a pre-intervention phase of the trial)
- •willing to consume study breads
排除标准
- •taking anti-hypertensive medication;
- •taking any medications known to interfere with blood pressure or calcium or bone metabolism;
- •Severe medical illness;
- •celiac disease;
- •hypercalcemia;
- •known intestinal malabsorption syndrome,
- •excessive alcohol use (>14 drinks/week);
- •pregnancy
研究组 & 干预措施
Usual-salt diet
Usual-salt diet followed for 5 weeks
干预措施: Usual-salt diet (Other)
Reduced-salt diet
Reduced-salt diet followed for 5 weeks
干预措施: Reduced-salt diet (Other)
结局指标
主要结局
Systolic blood pressure at end of intervention periods
时间窗: After 5 weeks of intervention
Measured as seated office systolic blood pressure at end of usual salt dietary period and at end of reduced-salt dietary period
次要结局
- Diastolic blood pressure(After 5 weeks of intervention)
- Urinary Calcium(After 5 weeks of intervention)
- Urinary N-telopeptides of Type I collagen(After 5 weeks of intervention)
- Serum Parathyroid Hormone(After 5 weeks of intervention)
- Serum C-telopeptide of Type I collagen(After 5 weeks of intervention)
- Serum Osteocalcin(After 5 weeks of intervention)
- Serum Bone-specific alkaline phosphatase(After 5 weeks of intervention)
- Plasma triglycerides(After 5 weeks of intervention)
- Serum total-cholesterol(After 5 weeks of intervention)
- Plasma LDL-cholesterol,(After 5 weeks of intervention)
- Plasma HDL-cholesterol(After 5 weeks of intervention)
研究者
Kevin D. Cashman
Professor of Food and Health
University College Cork