Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT02449148 |
Other study ID # |
DKFZ Study_ID 670 |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
May 2015 |
Est. completion date |
May 2017 |
Study information
Verified date |
December 2021 |
Source |
German Cancer Research Center |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
This study evaluates the effect of intermittent calorie restriction versus continued calorie
restriction on weight loss, gene expression profile of subcutaneous adipose tissue and
abdominal fat distribution.
Description:
Since obesity has become a major public health concern appropriate strategies are needed in
order to reduce obesity-related health risks in later life span. Obesity is one of the main
risk factors not only for diabetes and cardiovascular diseases, but also for several types of
cancer. Several key mechanisms, which may link obesity, metabolic dysregulation and cancer
risk, such as obesity-driven inflammation, altered adipokine, growth factor and sex hormone
signaling, and changes in the microbiota have been identified.
Various studies have shown that continuous calorie restriction (CCR) and exercise are
effective strategies to enforce weight-loss and improve biomarker profiles. Intermittent
calorie restriction (ICR) as a novel strategy might induce favorable metabolic changes and
lead to higher compliance rates. The concept of this diet regime is very simple e.g. 2
days/week of fasting following a standardized diet covering 25 % of energy needs and 5
days/week of ad libitum consumption. To verify the effectiveness of ICR as an alternative
weight loss strategy to CCR controlled intervention trials are required. Although both CCR
and ICR induce a negative energy balance, the metabolic effect on human physiology might
differ.
Within the HELENA-study 50 non-smoking adults (men and women aged 35 to 65 years) with an BMI
≥ 25 kg/m² and ≤ 40 kg/m² will be randomly assigned to each of the intervention arms: (1) ICR
arm (2 day/week fasting, i.e. 25% energy intake, energy intake of 100% on 5 days/week leading
to a weekly average energy intake of ~80%) (2) CCR arm (daily energy intake of 80%) and 3)
control arm (general advice on healthy nutrition).
The trial will last 1 year, with an intervention phase of 12 weeks (weeks 0-12; intervention;
close contact with participants), followed by a maintenance phase (weeks 13-24; maintenance;
regular, but less frequent contact with participants) and a follow-up phase (weeks 25-52).
Biological specimens will be collected as follows:
Baseline (T0, week 1): Blood, urine, stool and subcutaneous adipose tissue samples; After 3
months (T1, week 13): Blood, urine, stool and subcutaneous adipose tissue samples; After 6
months (T2, week 25): Blood, urine, and stool; After 12 months (T3, week 52): Blood and
urine; Magnet resonance tomography imaging (MRI, at T0, T1 and T3) and lifestyle assessments
(nutrition behavior, physical activity and quality of life, T0-T3) will be performed to
unravel the link to fat distribution, metabolic changes, health and lifestyle. The primary
objective of the three-arm randomized controlled intervention trial is to investigate the
effect of nutrition intervention on body weight and gene expression profile in subcutaneous
adipose tissue of overweight and obese individuals. We hypothesize that better compliance
rates will be achieved by the ICR rather than by the CCR group and that ICR will show a
higher sustainability with respect to weight loss, weight maintenance, and biomarker
profiles. The purpose of this study is further to analyze if the nutrition interventions and
associated weight loss have different effects on abdominal fat distribution and liver fat
content.
The statistical analysis will be carried out by using the SAS statistical software [SAS
Institute Inc., Cary, NC, USA] or comparable software. Descriptive statistics, correlations
and univariate analyses will be used to get insight on general characteristics of
participants in the intervention groups. For the primary objective, two sided t-test and
ANCOVA modelling will be performed to investigate whether changes in gene expression levels
are affected by nutrition intervention. Comparisons between two groups (e.g. ICR and CCR or
CCR/ICR and control group) will be carried out using t-tests and parallel comparison across
the three groups will be carried out using ANCOVA models. Where applicable, the analyses will
include adjustments for confounders, specially age and gender. Likewise, stratified analysis
will be carried out as necessary. ANCOVA models will be performed to evaluate the effects of
nutrition intervention on biomarker profiles, adjusted by strata age and gender. Similar
evaluations will be performed for fat distribution patterns, quality of life, physical
activity and nutrition patterns. In addition, correlation and linear regression analyses will
be performed to measure effects of weight-loss, gene expression levels and metabolic
profiles, controlled by nutrition intervention group.