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Trial registered on ANZCTR


Registration number
ACTRN12616001046493
Ethics application status
Approved
Date submitted
2/08/2016
Date registered
5/08/2016
Date last updated
21/04/2017
Type of registration
Prospectively registered

Titles & IDs
Public title
Effect of a Mediterranean diet with fresh lean Australian pork on blood pressure, cardiovascular risk factors and cognition, mood and wellbeing in high risk individuals.
Scientific title
Effect of a Mediterranean diet with fresh lean Australian pork on blood pressure, cardiovascular risk factors and cognition, mood and wellbeing in high risk individuals.
Secondary ID [1] 289806 0
none
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cardiovascular Health 299723 0
Cardiometabolic Health 299724 0
Wellbeing and cognitive performance 299725 0
Condition category
Condition code
Diet and Nutrition 299656 299656 0 0
Other diet and nutrition disorders
Cardiovascular 299657 299657 0 0
Hypertension
Mental Health 299658 299658 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is a randomised cross-over dietary intervention trial with two 8-week dietary phases (Mediterranean diet and low fat diet) separated by an 8 week washout period. Total duration of the trial is 24 weeks. Outcome measures will be recorded at the start and end of each 8 week phase (ie baseline, week8, week 16, week 24).

At baseline volunteers will meet with the dietitian, for approximately 30mintues, and received instructions regarding their dietary prescription for the next 8 weeks. Volunteers will be prescribed their allocated diet, receive recipes and their sample menu (during Mediterranean diet) to help guide food choices. Volunteers will be given advice on eating out strategies to assist with compliance to their allocated diet.They will be issued a diet checklist to ensure they are complying with the diet. During the MedDiet phase, volunteers will receive lean fresh Australian pork plus foods characteristic of the MedDiet (olive oil, canned fish, nuts etc) to assist with compliance. All volunteers will be asked to maintain their usual exercise pattern. Volunteers will be asked to return fortnightly to see the dietitian (for 15-30 minutes), have their weight measured, return checklists, collect study foods and discuss any problems that may have arisen during the intervention. During the washout periods between diet phases, volunteers will be asked to return to following their habitual diet.

Mediterranean Diet (MedDiet) with pork.
The MedDiet is characterised by a variety of foods including wholegrain cereals, nuts, legumes, extra virgin olive oil, red wine, small amounts of red meat, low intakes of dairy (mainly yoghurt and cheese), fish, fruits and vegetables. The MedDiet will be based on the PREDIMED-EVOO diet as described by Estruch R et al (NEJM 2013) and fresh lean pork will be included as an alternative option for protein food.

Guidelines for following the MedDiet are adapted from Estruch R et al 2013 NEJM, include:
Abundant use of extra virgin olive oil for cooking and dressing vegetables and salads
2-3 or more daily servings of fresh fruits including 100% natural juices
3 or more weekly servings of legumes (75g per serve)
3 or more weekly servings of fish and seafood (at least one serving of oily fish) (100g per serve)
3 or more weekly serving of nuts (7.5g hazelnuts, 15g walnuts, 7.5g almonds) or seeds (30g per serve)
Ad-libitum consumption of wholegrain cereal products (bread, pasta, rice, cereal), nuts, fish, eggs, cheese and raw and cooked vegetables.
Select white meats (poultry without skin) instead of red meats or processed meats (burgers, sausages, deli meats)
Limit consumption of cured ham, red meat (remove all visible fat) to 1 or less serve/week
Remove chicken skin
Cook regularly (at least twice a week) with tomato, garlic and onion
Dress vegetables, pasta, rice and other dishes with tomato, garlic and onion
Eliminate or limit the consumption of cream, butter, margarine and discretionary foods

Adherence to the MedDiet will be assessed using a 14-point adherence score assessed fortnightly. Compliance to the MedDiet will be assessed from weighed food records conducted at the beginning and end of each dietary phase and through daily checklists. All volunteers will see the dietitian fortnightly who will discuss strategies to maintain compliance to the MedDiet.
Intervention code [1] 295480 0
Prevention
Intervention code [2] 295516 0
Lifestyle
Comparator / control treatment
The comparator treatment is a low fat diet.

Low-fat diet (LFD)
The LFD will be based on the PREDIMED control diet (Estruch R et al 2013 NEJM) following American Heart Association in combination with local recommendations for the Heart Foundation of Australia. Volunteers will maintain the basis of their habitual diet however will be asked to modify their intake to choose low fat foods.

Guidelines include:
Purchase low fat foods
Choosing lean cuts of meat and trimming all visible fat from meats and remove skin from chicken
Maintain habitual pork consumption
Eat fish instead of meat 2-3 times per week
Avoid processed meats including bacon, beef and lamb
Cooking with less fat avoiding use oil, butter or fat-based sauces (canola spray is recommended)
Employ low fat cooking methods
Remove excess fat from foods (i.e. skim fat from top of casseroles/stews etc.)
Use spreads sparingly
Limit take-away, fried and commercial foods
Limit consumption of nuts
Avoid, cakes, pies, pastries, chips etc.

Adherence to the LFD will be assessed using a 9-point adherence score assessed fortnightly. Compliance to the LFD will be assessed from weighed food records conducted at the beginning and end of each dietary phase. All volunteers will see the dietitian fortnightly who will discuss strategies to maintain compliance to both dietary interventions
Control group
Active

Outcomes
Primary outcome [1] 299122 0
Blood pressure will be determined by automatic oscillatory using a Digital Blood Pressure Monitor. Volunteers will monitor blood pressure three times a day, at home, for 6 days generating 54 data points of blood pressure readings where the average will be taken.
Timepoint [1] 299122 0
Home measured blood pressure will be measured 6 days prior to baseline, during weeks 7-8, 15-16 and 23-24.
Secondary outcome [1] 326240 0
% body fat, assessed by dual X-ray absorptiometry (DEXA)
Timepoint [1] 326240 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [2] 326241 0
Heart Rate, measured by automatic oscillometry.
Timepoint [2] 326241 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [3] 326242 0
Body Mass Index, calculated as weight divided by height in meters squared. Weight will be measured using digital scales while volunteers are wearing minimal clothing and no shoes. Height will be measured at baseline using a wall-mounted stadiometer.
Timepoint [3] 326242 0
Assessed at screenig and at baseline and 8,16 and 24 weeks.
Secondary outcome [4] 326243 0
Waist and hip circumference (in centimeters) will be measured according to the ISAK International Standards for Anthropometric Assessment. Waist/Hip ratio will be calculated by dividing waits/hip circumference.
Timepoint [4] 326243 0
Assessed at baseline and 8,16 and 24 weeks. Waist will be assessed at screening.
Secondary outcome [5] 326244 0
Cognitive performance will be assessed using the CANTAB 'registered trademark' computerised test battery: visual and verbal memory.
Timepoint [5] 326244 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [6] 326245 0
Cognitive performance will be assessed using the CANTAB 'registered trademark' computerised test battery: speed of processing (reaction and attention)
Timepoint [6] 326245 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [7] 326246 0
Cognitive performance will be assessed using the CANTAB 'registered trademark' computerised test battery: executive function
Timepoint [7] 326246 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [8] 326247 0
Cognitive performance will be assessed using the CANTAB 'registered trademark' computerised test battery: social cognition
Timepoint [8] 326247 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [9] 326248 0
Cognitive performance will be assessed using the CANTAB 'registered trademark' computerised test battery: decision making
Timepoint [9] 326248 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [10] 326252 0
Addenbrooke's Cognitive Examination Revised (ACE-R) is a brief cognitive test battery that has been validated for use to detect early cognitive dysfunction through scoring five different cognitive domains (memory, attention/orientation, fluency, language and visouspatial). (Mioshi et al 2006) This will be used at screening to rule out dementia and Alzhemier's disease and as an outcome measure as it is sensitive in detecting very mild-cognitive impairment.
Timepoint [10] 326252 0
Assessed at screening, baseline and 8,16 and 24 weeks.
Secondary outcome [11] 326253 0
Mood will be assessed using the Profile of Mood State (POMS) questionnaire (McNair 1971).
Timepoint [11] 326253 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [12] 326254 0
The CAIDE Dementia Risk score was developed to identify individuals at increased risk for developing dementia (20 years later) based on midlife presence of metabolic and vascular risk factors that would potentially benefit from preventative interventions to reduce their risk (Sindi 2015).
The CAIDE will be assessed in volunteers aged between 45-65 years (validated in this age range)
Timepoint [12] 326254 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [13] 326255 0
Framingham Risk Score is a gender specific calculator used to estimate an individual's 10 year risk of developing cardiovasular disease.
Timepoint [13] 326255 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [14] 326256 0
Physical health-related quality of life will be assessed using the Short Form Health Survey (SF36V2)
Timepoint [14] 326256 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [15] 326257 0
Insulin Resistance calculated from serum insulin and glucose. Insulin resistance will be calculated using the Homeostasis Model Assessment (HOMA2) Calculator.
Timepoint [15] 326257 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [16] 326258 0
Plasma C-reactive protein (inflammatory marker)
Timepoint [16] 326258 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [17] 326259 0
Plasma total Cholesterol levels
Timepoint [17] 326259 0
Assessed at screening then baseline and 8,16 and 24 weeks.
Secondary outcome [18] 326260 0
Plasma low denstiy lipoprotein (LDL) cholesterol levels
Timepoint [18] 326260 0
Assessed at screening then baseline and 8,16 and 24 weeks.
Secondary outcome [19] 326261 0
Plasma high density lipoprotein (HDL) cholesterol levels
Timepoint [19] 326261 0
Assessed at screening then baseline and 8,16 and 24 weeks.
Secondary outcome [20] 326262 0
Plasma triglyceride levels
Timepoint [20] 326262 0
Assessed at screenig then baseline and 8,16 and 24 weeks.
Secondary outcome [21] 326263 0
Apolipoprotein E-4 allele (APOE4, indicator of increased risk for Alzheimer's Disease) as assessed from blood sample using the TaqMan 'registered trademark' SNP Genotyping Assay Kit (Applied Biosystems, Warrington, UK) (Koch et al 2002)
Timepoint [21] 326263 0
Assessed at baseline
Secondary outcome [22] 326264 0
Fat Mass (DEXA)
Timepoint [22] 326264 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [23] 326265 0
Lean Mass (DEXA)
Timepoint [23] 326265 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [24] 326266 0
Abdominal Body fat (DEXA)
Timepoint [24] 326266 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [25] 326267 0
Faecal Microbiome profile. The omnigene GUT collection system will provide an easy non-invasive stool collection kit for volunteers to use at home.
Timepoint [25] 326267 0
Assessed at baseline and 8,16 and 24 weeks.
Secondary outcome [26] 326268 0
Mediterranean Dietary Adherence using the 14-point MedDiet adherence tool and weighed food records.
Timepoint [26] 326268 0
Assessed at screening and then at baseline and every fortnight of the MedDiet phase (total 6 occasions).
Secondary outcome [27] 326319 0
Low Fat Dietary Adherence using the 9-point low fat diet adherence tool (Estruch et al 2013).
Timepoint [27] 326319 0
Baseline and every fortnight of the low fat diet phase (total 5 occasions)
Secondary outcome [28] 326320 0
Plasma levels of glucose will be assessed using standard methods via venepuncture. Finger prick glucose will be taken using a lancet and measured using a glucometer at screening.
Timepoint [28] 326320 0
Assessed at screening then baseline and at week 8, 16 and 24.
Secondary outcome [29] 326321 0
Serum levels of insulin
Timepoint [29] 326321 0
Assessed at baseline and at week 8, 16 and 24.
Secondary outcome [30] 326322 0
Energy and macro and micronutrient intakes will be calculated from 6 day weighed food records entered into Foodworks Professional Software program.
Timepoint [30] 326322 0
Assessed at baseline and at week 8, 16 and 24.
Secondary outcome [31] 326323 0
In-clinic assessed blood pressure will be determined by automatic oscillatory using a Digital Blood Pressure Monitor. On each occasion 3 readings will be taken spaced at least 1 minute apart, and the average of the readings will be used.
Timepoint [31] 326323 0
At screening, then at baseline and at weeks 8, 16 and 24.
Secondary outcome [32] 326360 0
Mental health-related quality of life; will be assessed using the Short Form Health Survey (SF36V2)
Timepoint [32] 326360 0
At baseline, week 8, 16 and 24.
Secondary outcome [33] 326361 0
Social health-related quality of life will be assessed using the Short Form Health Survey (SF36V2)
Timepoint [33] 326361 0
At baseline, week 8, 16, and 24.

Eligibility
Key inclusion criteria
Free-living non-smoking men and women, aged between 45-75 years with elevated SBP equal to or above 120mmHg (high-normal range) and not on antihypertensive medication,
who habitually consume 1 or less serves of fresh pork per week
WITH at least 2 risk factors for CVD:

1. overweight/obese with BMI equal to or above 25kg/m2
2. waist circumference men greater than94cm, women greater than 80cm
3. dyslipidemia one of the following: total cholesterol equal to or greater than 5.5mM, triglycerides equal to or greater than 2.0mM, LDL equal to or greater than 3.5, HDL men equal to or less than 0.9 women less than 1.0,
4. impaired glucose tolerance (fasted glucose between 6.1-7.8mmol/L)
5. Family history of CVD (MI or sudden death before 55yrs for men or 65yrs for female 1st degree relatives)
6. Family history of type 2 diabetes mellitus (T2DM)
Minimum age
45 Years
Maximum age
75 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Person considered by the investigator to be unwilling, unlikely or unable to comprehend or comply with the study protocol
2. Unable to consume pork
3. Previous/current traumatic head/brain injury, neurological or psychiatric conditions
4. Previous stroke
5. Use of anti-depressant, anxiety or neurological or psychiatric medication
6. Current or recent (in the last 6 months) malignancy
7. Major liver, kidney, respiratory, gastrointestinal disease
8. Current CVD or angina
9. Actively trying to lose weight
10. Pregnancy/lactating
11. Smoker (within the last 6months)
12. Diagnosed T2DM
13. Allergy/sensitivity to nuts, seafood, etc. relevant to the dietary protocol
14. Illegal drug use or alcoholism
15. Weight >135kg (DEXA limitations)
16. Diagnosis of Alzheimer’s Disease, dementia

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)
An independent holder of the randomisation schedule who will have no contact with the volunteers or be involved in data analysis, will perform treatment allocation.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Volunteers who meet eligibility criteria will be stratified according to gender and age and randomly allocated (by a process of minimisation) to one of two dietary groups to commence the intervention.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Two 8-week dietary phases will be separated by an 8-week washout period where the volunteer will return to their habitual diet before commencing their crossover diet.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
One-way ANOVA and Chi square will be used to compare baseline demographic, cardiometabolic, cognitive, wellbeing and dietary characteristics between those who completed the study and those who withdrew. Mixed effects models will be used to assess the effects of treatment, and possible carryover or period effects for each of the outcomes separately. Carry over effects will be assessed by comparing baseline values within each group between the two periods using a Group X Period interaction term in multilevel analysis. Treatment-period effects will be explored by comparing the treatment effects using a treatment X period interaction term in multilevel analysis. We will also assess possible seasonal effects by including a term for treatment X season interaction in a secondary analysis with season coded as a binary variable for Autumn or spring versus Winter or Summer.

Diet x Period X Energy intake interaction terms will be used to determine whether there are any changes in diet (total energy, macronutrient intakes) between the two diet phases. All statistical analyses will be conducted using SPSS for Windows, version 21.0 (SPSS Inc., Chicago, IL, USA) and Stata (version 14, Statacorp, College Station, Texas). Data will be presented as means +/- standard deviation (SD) for descriptives and as means +/- standard error (SEM) for reporting estimated effects. P < 0.05 is deemed significance.

A sample size of 30 participants has been calculated on the primary outcome of blood pressure assessed as home blood pressure. 30 volunteers will provide >90% power to detect a 2.5 mmHg difference in mean home systolic blood pressure assuming a within-group SD of 14 mm Hg based on our previous studies, a correlation between hourly measures of 0.6, a correlation between mean home systolic blood pressures at each time point of 0.6, and a minimum of 50 blood pressure measurements per volunteer. This calculation is based on a between group comparison of means using a type I error rate of 0.017.

A 2.5mmHg reduction in blood pressure is clinically relevant. Whilst this reduction seems small for the individual, at the population level this reduction translates to a 7-8% to up to 15% risk reduction in stroke, hypertension and CVD. With a PREDIMED-nuts diet together with other dietary bioactives, we could see as much as a 4-5 mmHg reduction in blood pressure particularly in an ‘at-risk’ population.

To account for an approximate 10% drop-out rate based on our past trials, we will recruit an additional 9 volunteers. Total volunteers to be recruited is 39.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
1/09/2016
Actual
25/01/2017
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
39
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
SA
Recruitment postcode(s) [1] 13888 0
5001 - Adelaide

Funding & Sponsors
Funding source category [1] 294196 0
Other
Name [1] 294196 0
Pork CRC Pty Ltd
Country [1] 294196 0
Australia
Primary sponsor type
University
Name
University of South Australia
Address
GPO Box 2471, Adelaide 5001, South Australia
Country
Australia
Secondary sponsor category [1] 293020 0
Individual
Name [1] 293020 0
Dr Karen Murphy
Address [1] 293020 0
Alliance for Research in exercise, Nutrition and Activity (ARENA), University of South Australia, GPO Box 2471, Adelaide 5001, South Australia
Country [1] 293020 0
Australia
Secondary sponsor category [2] 293021 0
Individual
Name [2] 293021 0
Prof. Jonathan Hodgson
Address [2] 293021 0
Medicine and Pharmacology Royal Perth Hospital Unit, The University of Western Australia (M500), 35 Stirling Highway, Crawley, Western Australia 6009
Country [2] 293021 0
Australia
Secondary sponsor category [3] 293022 0
Individual
Name [3] 293022 0
Dr Hannah Keage
Address [3] 293022 0
School of Psychology, Social Work, and Social Policy, University of South Australia, May Wheaton Building, Level 2, H2-19, Magill Campus, GPO Box 2471, Adelaide 5001, South Australia
Country [3] 293022 0
Australia
Secondary sponsor category [4] 293023 0
Individual
Name [4] 293023 0
Courtney Davis
Address [4] 293023 0
Alliance for Research in exercise, Nutrition and Activity (ARENA), University of South Australia, GPO Box 2471, Adelaide 5001, South Australia
Country [4] 293023 0
Australia
Secondary sponsor category [5] 293024 0
Individual
Name [5] 293024 0
Alexandra Wade
Address [5] 293024 0
Alliance for Research in exercise, Nutrition and Activity (ARENA), University of South Australia, GPO Box 2471, Adelaide 5001, South Australia
Country [5] 293024 0
Australia
Secondary sponsor category [6] 293025 0
Individual
Name [6] 293025 0
Prof Richard Woodman
Address [6] 293025 0
Flinder University of South Australia, Flinders Centre for Epidemiology and Biostatistics, Flinders University, Adelaide, GPO Box 2100, Adelaide 5001, South Australia
Country [6] 293025 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 295599 0
Universtiy of south Australia Human research Ethics Committee
Ethics committee address [1] 295599 0
Ethics committee country [1] 295599 0
Australia
Date submitted for ethics approval [1] 295599 0
30/06/2016
Approval date [1] 295599 0
02/08/2016
Ethics approval number [1] 295599 0
35662

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 67878 0
Dr Karen Murphy
Address 67878 0
Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, GPO Box 2471, Adelaide 5001, South Australia
Country 67878 0
Australia
Phone 67878 0
+61 8 8302 1033
Fax 67878 0
Email 67878 0
Karen.Murphy@unisa.edu.au
Contact person for public queries
Name 67879 0
Karen Murphy
Address 67879 0
Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, GPO Box 2471, Adelaide 5001, South Australia
Country 67879 0
Australia
Phone 67879 0
+61 8 83021033
Fax 67879 0
Email 67879 0
Karen.Murphy@unisa.edu.au
Contact person for scientific queries
Name 67880 0
Karen Murphy
Address 67880 0
Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, GPO Box 2471, Adelaide 5001, South Australia
Country 67880 0
Australia
Phone 67880 0
+61 8 83021033
Fax 67880 0
Email 67880 0
Karen.Murphy@unisa.edu.au

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseIncluding pork in the Mediterranean diet for an Australian population: Protocol for a randomised controlled trial assessing cardiovascular risk and cognitive function.2017https://dx.doi.org/10.1186/s12937-017-0306-x
EmbaseA mediterranean diet with fresh, lean pork improves processing speed and mood: Cognitive findings from the medpork randomised controlled trial.2019https://dx.doi.org/10.3390/nu11071521
EmbaseEffects of Mediterranean diet supplemented with lean pork on blood pressure and markers of cardiovascular risk: Findings from the MedPork trial.2019https://dx.doi.org/10.1017/S0007114519001168
N.B. These documents automatically identified may not have been verified by the study sponsor.