Trial registered on ANZCTR

Trial ID
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
South Pacific Islands Resist diabetes with Intense Training: A randomised trial
Scientific title
The SPIRIT Study: South Pacific Islands Resist diabetes with Intense Training: A randomised trial
Secondary ID [1] 1213 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obesity 2551 0
type 2 diabetes 2552 0
Condition category
Condition code
Metabolic and Endocrine 2652 2652 0 0
Public Health 252418 252418 0 0
Health promotion/education

Study type
Description of intervention(s) / exposure
16 weeks of progressive resistance training (weight lifting), three times per week, 45 min per session on eight machine-based resistance exercises in a circuit format: seated leg press, knee extension, knee flexion, chest press, lat pulldowns, overhead press, biceps curls, triceps extension (Cybex International, Medway, MA). Initial weights starting weights determined as a percentage of the extrapolated 1-repetition maximum (1RM) as previously described by Brzycki et al (1993). Thereafter using a graduated periodized regimen where subjects progress from 65% to 85% of their extrapolated 1RM over the course of phase 1, two sets at 85% during phase 2, three sets at 85% during phase 3, and a continuation of three sets at 85% until conclusion of the intervention. Perform 6 to 8 repetitions with a 1 minute rest between sets. Workloads increased by 5% when subjects can perform 10 repetitions. Onsite exercise leaders supervised by lead clinical exercise physiologist encourage exercise at a a perceived exertion of “hard,” or 15, on the Borg scale.
Intervention code [1] 2283 0
Comparator / control treatment
16 weeks of aerobic training: 3 times per week, 45 min per session, performing a graduated progressive cycle ergometry (Life Fitness, Schiller Park, IL) protocol in parallel with the resistance training group. Gradual progression of 5 to 10% workload to minimise delayed onset muscle soreness. Subjects progressed from 65 to 85% of their heart rate reserve and encouraged to sustain a perceived exertion of “hard” on the Borg scale. Heart rate and blood pressure monitored and recorded at peak steady state workloads. Workloads (watts) and duration at peak intensity increased to accommodate subjects’ improved fitness levels. Direct supervision by exercise leaders and lead clinical exercise physiologist.
Control group

Primary outcome [1] 3562 0
glycaemic control (haemoglobin A1c): Determined by ion exchange high pressure liquid chromatography using the Bio-Rad D-10 analyzer (Bio-Rad Laboratories, Hercules, CA) with a coefficient of variation (CV) of 3%.
Timepoint [1] 3562 0
baseline and 16 weeks
Secondary outcome [1] 5962 0
Insulin resistance: Determined from fasting glucose and insulin using the most recent HOMA2-IR calculator (version 2.2.2, Oxford University).
Timepoint [1] 5962 0
baseline and 16 weeks
Secondary outcome [2] 5979 0
Blood lipids (Total Cholesterol, High Density Lipoprotein (HDL), Low Density Lipoprotein (LDL), Triglycerides (TG) were determined via standard enzymatic methods (Roche/Hitachi lipid assay kits) with a Roche Modular Analyzer with a CV of 3% on each assay. LDL mathematically determined as total cholesterol minus HDL minus (0.45 x TG).
Timepoint [2] 5979 0
baseline and 16 weeks
Secondary outcome [3] 5980 0
C-Reactive Protein: Determined by latex agglutination method on the Roche Modular Analyzer with a CV of 4%.
Timepoint [3] 5980 0
baseline and 16 weeks
Secondary outcome [4] 5981 0
Adiponectin: Determined by radioimmunoassay (Linco Research, St. Charles, MO, USA) with a CV of 8.8%.
Timepoint [4] 5981 0
baseline and 16 weeks
Secondary outcome [5] 5982 0
Anthropometric indices (Height, weight, Body Mass Index (BMI), waist and hip circumference, waist/hip ratio:

Height and weight measured to the nearest 0.1cm and 0.1kg on a standard hospital-grade stadiometer and scale, respectively. BMI calculated from standard formula: kg/m2. Waist circumference was measured to the nearest 0.1cm at the end of normal expiration and the midpoint between the lower costal margin and the iliac crest using, and hip circumference taken with feet together at the widest protuberance of the buttocks, using a retractable steel tape measure (model F10-02. KDS Corporation, Japan).
Timepoint [5] 5982 0
baseline and 16 weeks
Secondary outcome [6] 5983 0
Body composition: Lean body mass (LBM), fat mass (FM), and percent body fat (%BF) estimated via bioelectrical impedance analysis (BIA) on a Tanita TBF-310 analyzer (Tanita Corporation, Arlington Heights, Illinois, USA).
Timepoint [6] 5983 0
baseline and 16 weeks
Secondary outcome [7] 5984 0
haemodynamics (Heart rate (HR) and Blood Pressure (BP)): Seated blood pressure was measured in duplicate on the left arm after 5 minutes rest on a standard hospital-grade sphygmomanometer. Heart rate measured by counting radial pulse for a full 60 seconds. Exercise pulse determined manually on all subjects, but corroborated by use of pulse monitor on aerobic equipment.
Timepoint [7] 5984 0
baseline and 16 weeks
Secondary outcome [8] 5985 0
Dynamic upper and lower body strength: Due to level of obesity and deconditioning in this population and because strength was only determined as a means to identify starting weights, a 1-Repetition Max (1-RM) was deemed unnecessary. Instead a 10RM as determined by the protocol set forth by Brzycki (1993) was more appropriate to minimise delayed onset muscle soreness and possibly minimise early dropout.
Timepoint [8] 5985 0
baseline and 16 weeks
Secondary outcome [9] 5986 0
Quality of Life Short-Form 36(SF-36) questionnaire.

The SF36 quality of life questionnaire is comprised of 36 questions which encompass 8 different areas of physical and mental health and is useful for comparing the burden of different diseases, differentiating the health benefits produced by different treatments, and in screening individual patients.
Timepoint [9] 5986 0
baseline and 16 weeks
Secondary outcome [10] 5987 0
Activity Levels (International Physical Activity Questionnaire)
Timepoint [10] 5987 0
baseline and 16 weeks
Secondary outcome [11] 5988 0
muscle markers (muscle fibre type and cross-sectional area, mitochondrial density, intramuscular triglyceride, capillary density, GLUT4). Method: standard biopsy of vastus lateralis by highly trained/experienced doctor, snap frozen samples, later sectioned, mounted, and results determined by immunohistochemical methods and electron microscopy. Digital images captured analzyed on software to quantify indicated parameters.
Timepoint [11] 5988 0
baseline and 16 weeks

Key inclusion criteria
Self-identified Polynesian descent (Maori, Pacific Islands people).
Diagnosed type 2 diabetes.
Central obesity as defined by a waist girth of 88cm in women and 102cm in men.
No change in diabetes medications for previous two months.
No documented cardiac history or stable cardiac history for previous 6 months.
Not currently taking exogenous insulin injections.
Must be stable and medically managed.
Signed consent from their general practitioner (GP) or specialist.
Minimum age
18 Years
Maximum age
60 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Diabetic complications which may be worsened by weight lifting exercise.
Change in meds during previous 2 months.
Unstable cardiovascular disease, stroke, or other conditions which might be worsened by weight lifting exercise.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Concealed opaque envelope. Assignment following baseline testing.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computer-generated randomization list.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Recruitment outside Australia
Country [1] 657 0
New Zealand
State/province [1] 657 0

Funding & Sponsors
Funding source category [1] 2795 0
Name [1] 2795 0
Massey University
Address [1] 2795 0
PO Box 756
Country [1] 2795 0
New Zealand
Primary sponsor type
Massey University
PO Box 756
New Zealand
Secondary sponsor category [1] 2526 0
Name [1] 2526 0
Address [1] 2526 0
Country [1] 2526 0
Other collaborator category [1] 90 0
Name [1] 90 0
Capital and Coast District Health Board
Address [1] 90 0
Level 1/36 Tacy Street
Kilbirnie 6022, Wellington
(04) 387 1270
Country [1] 90 0
New Zealand
Other collaborator category [2] 91 0
Name [2] 91 0
National Heart Foundation
Address [2] 91 0
28 The Terrace
PO Box 5357
Lambton Quay
phone (04) 472 2780
Country [2] 91 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 258140 0
Central Regional Ethics Committee
Ethics committee address [1] 258140 0
Central Regional Ethics Committee
Ministry of Health
Level 2, 1-3 The Terrace
PO Box 5013
Ethics committee country [1] 258140 0
New Zealand
Date submitted for ethics approval [1] 258140 0
Approval date [1] 258140 0
Ethics approval number [1] 258140 0

Brief summary
A small number of multidisciplinary lifestyle interventions for diabetes prevention and weight reduction have been conducted in obese Polynesian (Maori and Pacific Islands people) populations but to date none were designed to isolate the specific impact of the exercise component. To our knowledge, no structured exercise trials have been conducted in obese Maori and Pacific Islands people with type 2 diabetes. Therefore, the purpose of this study was two-fold: (1) to evaluate whether high intensity resistance training (weight lifting) or aerobic exercise can improve glycemic control and associated cardiometabolic aberrations in sedentary Polynesian people with morbid obesity and diagnosed type 2 diabetes; and (2) to determine which type of exercise is more effective for improving glycemic control given an equivalent training intensity and duration. Because resistance training has been shown to improve overall muscle strength and metabolism, we hypothesised that this form of exercise would result in greater reductions in glycated haemoglobin
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 28186 0
Address 28186 0
Country 28186 0
Phone 28186 0
Fax 28186 0
Email 28186 0
Contact person for public queries
Name 11343 0
William R. Sukala,MSc
Address 11343 0
Massey University
PO Box 756
Country 11343 0
New Zealand
Phone 11343 0
+64 - 4 - 801 5799 ext 62290
Fax 11343 0
Email 11343 0
Contact person for scientific queries
Name 2271 0
William R. Sukala,MSc
Address 2271 0
Massey University
PO Box 756
Country 2271 0
New Zealand
Phone 2271 0
+64 - 4 - 801 5799 ext 62290
Fax 2271 0
Email 2271 0