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Trial registered on ANZCTR


Registration number
ACTRN12610000852055
Ethics application status
Approved
Date submitted
13/10/2010
Date registered
13/10/2010
Date last updated
9/02/2011
Type of registration
Retrospectively registered

Titles & IDs
Public title
Dietary approaches for treatment of the metabolic syndrome in overweight and obese women.
Scientific title
A randomised, controlled dietary intervention to evaluate the effect of a high protein diet compared with a high carbohydrate, high fibre diet on individual components of the metabolic syndrome and markers of cardiovascular disease risk in overweight and obese women.
Secondary ID [1] 252855 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Metabolic syndrome in overweight and obese women 258376 0
Diabetes prevention in overweight and obese women 258377 0
Insulin resistance in overweight and obese women 258379 0
Condition category
Condition code
Diet and Nutrition 258549 258549 0 0
Obesity
Metabolic and Endocrine 258550 258550 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants were randomised to one of two diets for eight weeks:

1. A hypocaloric (approximately 5500kJ/day) high protein diet (30% protein, 30% fat, 40% carbohydrate, ~25g total dietary fibre per day).
Intervention code [1] 257373 0
Lifestyle
Intervention code [2] 257384 0
Prevention
Intervention code [3] 257385 0
Treatment: Other
Comparator / control treatment
2. A hypocaloric (approximate 5500kJ/day) high carbohydrate, high fibre diet (20% protein, 30% fat, 50% carbohydrate, >35g total dietary fibre per day).

All participants were required to lose 5-10% of their initial bodyweight over the eight weeks by eating a diet specified in the guidelines prvided to them, and met with a study researcher on a fortnightly basis for a 30 minute nutritional counselling session and to be weighed.
Control group
Active

Outcomes
Primary outcome [1] 259387 0
Body weight (determined using electronic calibrated scales) and waist circumference (determined using a tape measure at the midpoint between the anterior superior iliac spine of the hip and bottom of the ribcage).
Timepoint [1] 259387 0
Baseline and week 8
Primary outcome [2] 259388 0
Total body fat, total lean mass and trunkal fat mass (measured by Dual Energy X-ray Anthropometry).
Timepoint [2] 259388 0
Baseline and week 8.
Primary outcome [3] 259389 0
Blood lipids, blood glucose, blood pressure and insulin sensitivity as measured by the Homeostasis Model Assessment for Insulin Resistance and by the McAuley Index.
Timepoint [3] 259389 0
Baseline and week 8.
Secondary outcome [1] 265920 0
Fasting plasma insulin, C-reactive protein, adiponectin, tumor necrosis factor alpha (TNF-alpha), plasminogen activator inhibitor -1 (PAI-1), interleukins 6, 8 and 18, grehlin, magnesium and serum uric acid.
Timepoint [1] 265920 0
Baseline and week 8.

Eligibility
Key inclusion criteria
Overweight (body mass index (BMI)> 27kg/m^2). Weight stable over last 3 months. Prepared to undergo dietary intervention and eat substantial amounts of dietary fibre including wholegrains, legumes and pulses.
Minimum age
18 Years
Maximum age
65 Years
Gender
Females
Can healthy volunteers participate?
No
Key exclusion criteria
No diabetes, psychiatric illness, drug or alcohol dependence that would affect ability to adhere to the dietary guidelines. No history of an eating disorder or renal or hepatic failure. Not on lipid lowering medications or medications known to affect metabolism. Not pregnant, lactating or planning to become pregnant in the next 8 weeks.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Sealed opaque envelopes containing treatment assignation was prepared by a research assistant who was not involved in the study in any other way, and allocation to participants was in sequential order.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Individuals were randomised to treatment groups stratified by age and body mass index. Strata were randomised in random sized blocks using the randomisation commands in Microsoft Excel.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Safety/efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 2966 0
New Zealand
State/province [1] 2966 0

Funding & Sponsors
Funding source category [1] 257824 0
Other Collaborative groups
Name [1] 257824 0
Riddet Institute
Address [1] 257824 0
Private Bag 11222
Palmerston North 4442
Country [1] 257824 0
New Zealand
Primary sponsor type
Individual
Name
Professor Jim Mann
Address
Department of Human Nutrition
University of Otago
PO Box 56
Dunedin 9054
Country
New Zealand
Secondary sponsor category [1] 257029 0
Individual
Name [1] 257029 0
Lisa Te Morenga
Address [1] 257029 0
Department of Human Nutrition
University of Otago
PO Box 56
Dunedin 9054
Country [1] 257029 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 259857 0
Otago Human Ethics Committee
Ethics committee address [1] 259857 0
Ethics committee country [1] 259857 0
New Zealand
Date submitted for ethics approval [1] 259857 0
Approval date [1] 259857 0
26/03/2008
Ethics approval number [1] 259857 0
1/08/0028

Summary
Brief summary
The metabolic syndrome is defined by a number of associated risk factors that cluster together in individuals increasing their risk of diabetes and heart disease. These factors include insulin resistance, abdominal obesity, high blood pressure, dyslipidaemia and raised blood sugar. The likelihood of dying of heart disease is increased three-fold in people with metabolic syndrome (diagnosed as having at least three risk factors). There is limited reporting on the prevalence of the metabolic syndrome in New Zealand, but reports suggest it could be more than 20% in adult New Zealanders with more than double the prevalence in adult Maori and Pacific Islanders. Correspondingly an estimated 7% of New Zealand adults have suffered a non-fatal heart disease event and the prevalence of diagnosed diabetes in New Zealand is estimated to be 4% in the general New Zealand population and as high as 12% in Maori and Pacific Islanders. These are likely to be underestimates and the prevalence is further increased when including estimates of undiagnosed cases.

Clearly, determining effective strategies for managing metabolic syndrome risk factors is warranted. A number of lifestyle interventions indicate that clinically important improvements in insulin sensitivity, body weight, hypertension and blood fats are achievable. However we currently have little indication of which dietary modifications will achieve the greatest change. Both dietary fibre and dietary protein have shown promise in numerous studies but results have been inconsistent and many questions remain unanswered.

This study attempts determine the ways and extent to which metabolic syndrome risk factors can be influenced by high fibre and high protein diets.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 31759 0
Address 31759 0
Country 31759 0
Phone 31759 0
Fax 31759 0
Email 31759 0
Contact person for public queries
Name 15006 0
Lisa Te Morenga
Address 15006 0
Department of Human Nutrition,
University of Otago,
PO Box 56,
Dunedin 9054
Country 15006 0
New Zealand
Phone 15006 0
+64 3 479 3978
Fax 15006 0
Email 15006 0
lisa.temorenga@otago.ac.nz
Contact person for scientific queries
Name 5934 0
Lisa Te Morenga
Address 5934 0
Department of Human Nutrition,
University of Otago,
PO Box 56,
Dunedin 9054
Country 5934 0
New Zealand
Phone 5934 0
+64 3 479 3978
Fax 5934 0
Email 5934 0
lisa.temorenga@otago.ac.nz

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary