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Trial registered on ANZCTR


Registration number
ACTRN12624001158550
Ethics application status
Approved
Date submitted
24/07/2024
Date registered
24/09/2024
Date last updated
24/09/2024
Date data sharing statement initially provided
24/09/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
Is there a difference in the ‘hunger’ hormone between Pacific Island and New Zealand European populations?
Scientific title
Ghrelin and sympathetic nerve activity in Pacific People (SNAPP)
Secondary ID [1] 312596 0
None
Universal Trial Number (UTN)
U1111-1311-0361
Trial acronym
SNAPP
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Health 334520 0
Diabetes Mellitus (DM) 334802 0
Condition category
Condition code
Cardiovascular 331136 331136 0 0
Normal development and function of the cardiovascular system
Metabolic and Endocrine 331137 331137 0 0
Diabetes

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is a non-therapeutic mechanistic physiological study.

All the following measurements and tests described will be conducted by a trained human physiologist staff member.

An initial familiarization visit will be conducted (~45 min) where an investigator will explain the nature of the procedures, answer any questions, and obtain written informed consent (as described above). Once consent has been obtained, assessment of the inclusion/exclusion criteria will be performed. Provided the inclusion criteria are met and there are no exclusion criteria, the participant will be enrolled into the study.
Anthropometric (height, weight, hip-to-waist ratio, %body fat), demographic, clinical information will be collected. More specifically the following questionnaires will be completed (all attached); 1) General Health Screening Questionnaire, 2) Quality of Life [EQ-5D-5L]; 3) International Physical Activity Questionnaire [IPAQ], and 3) 5-Factor Satiety Questionnaire.
Following this, participants will be familiarized with the study procedures. Microneurography will not be performed on this visit, but fully described and explained.

Participants will attend the laboratory for one experimental visit. Experimental sessions will be conducted at the Human Cardiorespiratory Physiology Laboratory, Clinical Research Centre Facility, Faculty of Medical and Health Sciences. The experimental visit will begin at ~9am and last ~2-3 hours. It will be scheduled ~2-7 days after the initial familiarization / screening visit.
The procedures will be reviewed again with the participant and remaining questions answered. Prior to the study visit participants will have been provided with a participant information leaflet, advising them of the following pre-study stipulations:
• No food intake overnight (i.e., ~8 hours prior to the study).
• No caffeine (e.g., coffee, coke, red bull) for 12 hours before the study.
• No alcohol on the day before the study and the day of the study.
• No exercise after 8:00pm the evening before the study and no exercise on the day of the study.
• No ‘over the counter’ (e.g., paracetamol) or prescribed medications (e.g., beta-blocker, ACE inhibitors) on the morning of the study.

At the experimental visit a blood sample will first be taken from an antecubital vein (~20 ml). Participants will be escorted to a phlebotomist located within the Clinical Research Unit at the University of Auckland ~200 meters from the laboratory. Once back in the laboratory, participants will then be asked to lay in a semi-recumbent position on a bed and assessments will then be made of; arterial stiffness and brachial artery FMD. Arterial stiffness measures requires a lightweight probes place at the carotid (neck) and radial (wrist) arteries and a cuff positioned around the upper thigh. Flow mediated dilatation (FMD) will be used to examine brachial artery function using ultrasound. This simply involves the inflation (5 min, 200 mmHg) and subsequent deflation of a standard blood pressure cuff around the upper arm (5 min).
Participants will then be instrumented for the measurement of heart rate, blood pressure, ventilation, and sympathetic nerve activity recordings (described below). Standardized autonomic function tests will then be administered. This will involve;
1) Resting baseline (10 min)
2) Slow deep breathing at 6 breaths/min (5 min)
3) Valsalva’s maneuver (3 x 30 s)
4) Hyperoxia (5 x 60 s)
Intervention code [1] 329109 0
Early detection / Screening
Comparator / control treatment
Healthy PI vs Healthy New Zealand European (control)
PI with DM vs New Zealand European with DM (control)
Healthy PI (control) vs PI with DM
Control group
Active

Outcomes
Primary outcome [1] 338887 0
Plasma levels of ghrelin in healthy Pacific Island (PI), compared to healthy New Zealanders (NZ) Europeans.
Timepoint [1] 338887 0
Plasma levels of ghrelin will be assessed once at the experimental visit in healthy PI and healthy NZ Europeans participants.
Primary outcome [2] 338888 0
Muscle sympathetic nerve activity (MSNA) in healthy Pacific Island (PI), compared to healthy New Zealanders (NZ) Europeans
Timepoint [2] 338888 0
MSNA in healthy PI and NZ Europeans participants will be assessed at four timepoints during the experimental visit: at rest, during slow deep breathing, during Valsalva manoeuvre and during hyperoxia.
Secondary outcome [1] 437800 0
The levels of ghrelin in type 2-diabetic (T2D) PI populations compared to T2D NZ European population.
Timepoint [1] 437800 0
Plasma levels of ghrelin will be assessed once at the experimental visit in T2D PI and T2D NZ Europeans participants.
Secondary outcome [2] 437801 0
MSNA in T2D PI compared to T2D NZ European.
Timepoint [2] 437801 0
MSNA in T2D PI and NZ Europeans participants will be assessed at four timepoints during the experimental visit: at rest, during slow deep breathing, during Valsalva manoeuvre and during hyperoxia.

Eligibility
Key inclusion criteria
All cohorts:
Men and women aged 18 years or older;

Cohort 1:
Healthy Pacific Island (both biological parents of Pacific Island origin) participants
Healthy NZ European (both biological parents of New Zealand origin) participants

Healthy Pacific Island (both biological parents of Pacific Island origin) living in NZ or Samoa; Cohort 2: Healthy NZ European participants;


Cohort 3:
T2D Pacific Island (both biological parents of Pacific Island origin) participants
T2D NZ European (both biological parents of New Zealand origin) participants
• Pacific Island (both biological parents of Pacific Island origin) and non-Pacific (NZ European) participants
• Healthy participants
• Type 2 diabetics
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
• Severe cardiac disease (e.g., coronary artery disease, heart failure)
• Significant arrhythmias (e.g., atrial fibrillation, previous VT / significant ventricular ectopy)
• Severe respiratory disease (e.g., chronic obstructive pulmonary disease)
• Significant renal or liver disease
• Significant neurological disease including diabetic neuropathy
• Significant obesity (i.e., not having a body fat% >30% for men and >42% for women)
• Current active treatment for cancer
• Inflammatory disease
• Current infection or pyrexial illness
• Uncontrolled thyroid disorders
• Recent (< 3 months) ischemic stroke
• Current pregnancy
• Inability to fully or appropriately provide consent (e.g., language issue, reading capability)
• Underlying medical conditions, which in the opinion of the Investigator place the participant at unacceptably high risk for participating in the study

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Cross-sectional interventional study.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



The people analysing the results/data
Intervention assignment
Other
Other design features
Different groups of participants (i.e., Healthy New Zealand European, Healthy Pacific Islander, Diabetic New Zealand European and Diabetic Pacific Islander) will receive the same intervention throughout the study.
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
Anthropometric (e.g., %body fat) and demographic (e.g., age) information gathered at primary screening will be quantified using basic statistics (mean, SD, Median, IQR) and graphical presentations (boxplots, histograms, scatter plots). Likewise, levels of primary and secondary outcomes will be similarly reported. Normal distribution will be evaluated using Shapiro-Wilk tests. Comparisons of normally distributed physiological variables for a given trial will be made using a t-test, and non-normally distributed data evaluated using a Mann–Whitney U test. In the event of potential confounding differences in baseline characteristics (e.g., physical activity), analysis of covariance (ANCOVA) will be employed. In line with the proposed multi-variable statistical modelling described, linear regression analysis will also be used to test for significant differences between ethnicities with regards to plasma ghrelin, SNA, VEGF and troponin with the anticipated confounders of adiposity, anthropometrics and potentially circulating glycaemic levels (HbA1c). Spearman’s Correlation analysis will be used to identify whether plasma ghrelin levels are correlated with SNA. Statistical analysis will be performed using commercially available statistical packages (eg., R, SPSS). Significance will be set at p < 0.05. Normally distributed data will be presented as mean (SD) while non-normally distributed data will be presented as median [interquartile range].

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
30/09/2024
Actual
Date of last participant enrolment
Anticipated
1/12/2026
Actual
Date of last data collection
Anticipated
21/12/2026
Actual
Sample size
Target
120
Accrual to date
Final
Recruitment outside Australia
Country [1] 26449 0
New Zealand
State/province [1] 26449 0
Auckland
Country [2] 26450 0
Samoa
State/province [2] 26450 0
Apia

Funding & Sponsors
Funding source category [1] 317023 0
Government body
Name [1] 317023 0
Health Research Council of New Zealand (HRC)
Country [1] 317023 0
New Zealand
Primary sponsor type
University
Name
University of Auckland
Address
Country
New Zealand
Secondary sponsor category [1] 319268 0
University
Name [1] 319268 0
University of Otago
Address [1] 319268 0
Country [1] 319268 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 315779 0
Northern B Health and Disability Ethics Committee 
Ethics committee address [1] 315779 0
Ethics committee country [1] 315779 0
New Zealand
Date submitted for ethics approval [1] 315779 0
11/06/2024
Approval date [1] 315779 0
11/07/2024
Ethics approval number [1] 315779 0
2024 EXP 20637

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

Contacts
Principal investigator
Name 135766 0
Prof Daryl Schwenke
Address 135766 0
Department of Physiology, School of Biomedical Sciences, University of Otago, PO Box 913, Dunedin 9054.
Country 135766 0
New Zealand
Phone 135766 0
+64221926416
Fax 135766 0
Email 135766 0
daryl.schwenke@otago.ac.nz
Contact person for public queries
Name 135767 0
Daryl Schwenke
Address 135767 0
Department of Physiology, School of Biomedical Sciences, University of Otago, PO Box 913, Dunedin 9054.
Country 135767 0
New Zealand
Phone 135767 0
+64221926416
Fax 135767 0
Email 135767 0
daryl.schwenke@otago.ac.nz
Contact person for scientific queries
Name 135768 0
Daryl Schwenke
Address 135768 0
Department of Physiology, School of Biomedical Sciences, University of Otago, PO Box 913, Dunedin 9054.
Country 135768 0
New Zealand
Phone 135768 0
+64221926416
Fax 135768 0
Email 135768 0
daryl.schwenke@otago.ac.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


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
No additional documents have been identified.