Low-carbohydrate Diet and Low-Density Lipoprotein - Cholesterol (LDL-c) Interindividual Variability

Официальное название

Exploring True Interindividual Heterogeneity of Cardiovascular Disease (CVD) Risk Factors in Response to Low-carbohydrate Diets Using a Replicate Crossover Randomised Controlled Trial

Обзор

Ketogenic diets are very low-carbohydrate diets that increase hepatic production of ketone bodies, which have several effects as substrates and signals. Ketogenic diets are used to manage some conditions (e.g., drug-resistant epilepsy), and their potential for managing many other conditions (e.g., cancer) is being actively explored. Indeed, the British Dietetic Association acknowledge the potential for ketogenic diets to improve glycaemic control to a greater extent than some other diets in people with type 2 diabetes. A lower fasting glucose is also relevant to future mortality in people without diabetes. Ketogenic diets are popular in the general population, with up to 15% of the UK following a low-carbohydrate diet. There is, therefore, great interest in ketogenic diets amongst people with and without health conditions. However, although the diet shows promising results in improving blood sugar levels, it has also shown to increase low-density lipoprotein-cholesterol (LDL-c) in some individuals, which has been linked to increased cardiovascular health risks. The aim of this project is to find the potential for personalised use of (or guidance to avoid) ketogenic diets for cardiovascular disease risk. To do that the investigators will ask participants to replicate 24 hours of a ketogenic diet and a control diet thrice each. This will allow the investigators to find variability between responses and have a better idea of individuals who could benefit (or not) from following the ketogenic diet.

Подробное описание

The study will be a controlled feeding replicate randomised controled trial with 3 cycles, each involving the pair of diets \[low carbohydrate (K) and control (C) diets\]. There will be 6 x 1-day periods (3 days low carbohydrate and 3 days control). Twenty individuals (body mass index: 18.5-35 kg/m2) will be recruited and randomised into one of the 8 possible sequences:

1. KC KC KC 2. KC KC CK 3. KC CK KC 4. KC CK CK 5. CK CK CK 6. CK CK KC 7. CK KC CK 8. CK KC KC A week before the interventions start, participants will visit the laboratory so that the investigators can perform indirect calorimetry and collect a blood sample for genotyping. During the week before the interventions, participants will wear activity monitors to determine habitual physical activity. Before each visit, participants will be asked to come to the lab in a rested and overnight fasted state. During the first trial visit, participants will have a dual-energy X-ray absorptiometry (DEXA) body scan to determine body composition. During all 12 study visits the investigators will perform a venepuncture in an antecubital vein and will collect 20 mL of blood.

Additionally, the investigators will also collect urine samples. After odd visits (1st, 3rd, 5th, 7th, 9th and 11th), participants will be supplied with their respective meals for the day (low carbohydrate or control) and will be asked to not eat anything else during the day.

Finally there will be a wash-out period of 6 days between laboratory visits. To keep consistency between trial days, participants will be asked to replicate physical activity levels performed during the 24 hours before the first trial, and during diet day (before second visit), so that these can be replicated for the following visits.

Вмешательства

• Другое control diet
  Diet will have macronutrients split with 50% carbohydrates, 15% protein and 35% fat. Also there will be a 0.66 ratio saturated:unsaturated fat
• Другое Low carbohydrate diet
  Diet will have macronutrients split with 8% carbohydrates, 15% protein and 77% fat. Also there will be a 0.66 ratio saturated:unsaturated fat

Первичные конечные точки

• Fasted plasma Low-density lipoprotein cholesterol (LDL-C) concentrations [Срок оценки: Pre and post following each intervention/control diet for 24 hours]

Вторичные конечные точки (1)

• Fasted glucose plasma glucose concentration [Срок оценки: Pre and post following each intervention/control diet for 24 hours]

Критерии участия

Критерии включения

• Age: >18 years
• Body mass index: 18.5-35 kg·m-2
• Low-Density Lipoprotein-cholesterol <4.9 mmol/L
• Non-fasting triglycerides <2.3 mmol/L

Критерии исключения

• weight instability (>5% change in body mass within last 3 months)
• smoker
• diagnosis of hypercholesterolaemia or any other lipid-related disease
• diagnosis of diabetes
• diagnosis of atherosclerotic cardiovascular disease
• elevated fasting glucose (>5.4 mmol/L)
• dietary intolerances or allergies or to other study procedures
• diagnosis of gastrointestinal disorders
• any other condition/medication that could introduce bias to the study
• already following a ketogenic diet
• not willing to follow a ketogenic diet
• unable to understand English language

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Распределение

Рандомизированное

Модель

Перекрёстный дизайн

Маскирование

Открытое

Основная цель

Фундаментальное исследование

Центры проведения

Великобритания · 1 центр

• University of Bath — Bath

Идентификаторы

NCT: NCT07675603 · 8791-12081

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

Открыть это исследование на ClinicalTrials.gov ↗