- Title
- The feasibility and efficacy of the type 2 diabetes PULSE (Prevention Using LifeStyle Education) randomised controlled trial: a self-administered, gender-tailored, multi-component lifestyle intervention for men at high-risk for type 2 diabetes
- Creator
- Aguiar, Elroy Joseph
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2015
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- The rising prevalence of type 2 diabetes mellitus (T2DM) is a global health concern. Seminal trials have demonstrated the strong efficacy of lifestyle intervention for T2DM prevention, however several evidence gaps have been identified in the existing T2DM prevention literature, namely, a lack of lifestyle interventions that: i) are pragmatic and scalable, ii) are gender-targeted for men, and iii) utilise a multi-component approach combing diet modification, aerobic exercise and resistance training. Thus, the central component of this thesis was the development and evaluation of the PULSE (Prevention Using LifeStyle Education) Program, a 6-month, self-administered, gender-tailored, multi-component lifestyle intervention for men at high-risk for developing T2DM. The primary aim was to evaluate the feasibility and efficacy of the PULSE Program for improving a range of risk factors strongly linked with T2DM development, including weight (primary outcome) and glycaemic markers. This thesis is presented as a series of manuscripts that address the primary and three secondary aims related to the development and evaluation of the PULSE Program. Secondary aims 1 and 2 are presented first as they provide the context for the main analysis of this thesis. Secondary Aim 1: To systematically review and meta-analyse the current evidence regarding multi-component lifestyle interventions (diet, aerobic exercise and resistance training) for type 2 diabetes mellitus prevention in adults at high-risk or with prediabetes. A systematic review was conducted to synthesise the evidence from T2DM prevention lifestyle interventions employing a multi-component lifestyle approach. In total 23 articles arising from 8 trials met the eligibility criteria. Methodological quality was mixed, with four of the eight trials classified with a high risk of bias. Meta-analysis favoured interventions over controls for weight loss (-3.79 kg [-6.13, -1.46; 95% CI], Z = 3.19, P = 0.001) and fasting plasma glucose (-0.13 mmol.L⁻¹ [-0.24, -0.02; 95% CI], Z = 2.42, P = 0.02). The results of this systematic review support a multi-component approach for T2DM prevention. Secondary Aim 2: To describe the characteristics of men identified at high-risk for developing type 2 diabetes mellitus using the Australian Diabetes Risk Assessment (AUSDRISK) tool, and determine the ability of the tool to identify men with prediabetes and metabolic syndrome. An analysis of the characteristics of men (n = 101) identified as at high-risk for developing T2DM (AUSDRISK score ≥ 12) was performed to evaluate the performance of the AUSDRISK tool. In total, 70% of men displayed elevations for FPG or HbA1C in the prediabetes range. Further, 62% were classified with metabolic syndrome. This study demonstrated the good ability of the AUSDRISK tool to identify men with substantial risk for the development of T2DM. Primary Aim: to evaluate the feasibility and efficacy of the PULSE Program for improving a range of risk factors strongly linked with type 2 diabetes mellitus development, including weight and glycaemic markers in men at high-risk for developing type 2 diabetes mellitus. A 6-month assessor-blinded, parallel-group randomised control trial with wait-list control group was conducted to assess the feasibility and efficacy of the PULSE Program. Men in the intervention (n = 53) group received the PULSE Program, which consisted of print and video resources regarding weight loss (SHED-IT Weight Loss Program), and two novel components focused on diet and exercise modification for type 2 diabetes mellitus prevention. The wait-list control group (n = 48) received no information until six months. The primary hypothesis was supported, i.e., men who received the intervention experienced greater weight loss and improvements in glycaemic markers at six months (immediate post-program and primary time point) compared to men in the wait-list control group. Group-by-time differences (mean [95% CI]) favoured the intervention versus control group for weight loss (primary outcome; -5.50 kg [95% CI: -7.40, -3.61], P < 0.001, Cohen’s d = 1.15) and HbA1C (-0.2% [95% CI: -0.3, -0.1], P = 0.002, d = 0.64). Changes in self-report dietary intake and physical activity (objectively measured and self-report) failed to reach statistical significance, despite within intervention group effects. Secondary Aim 3: To conduct a process evaluation of the PULSE Program randomised controlled trial to examine the trial’s design and its intervention program. A process evaluation was conducted at six months to evaluate the feasibility of the trial’s design and the intervention program. Overall, the design of the trial (wait-list control group design, recruitment and selection procedures, randomisation and stratification protocol, intervention length, selection of primary and secondary outcomes) was considered feasible. Further, intervention participants reported high levels of engagement and satisfaction with the program. Although adherence to self-monitoring was not optimal, with only 13% of men meeting the requisite criteria, significant associations were observed between self-monitoring of weekly weight and change in weight, waist circumference and fat mass. Self-monitoring of daily exercise was significantly associated with changes in waist circumference and objectively measured physical activity (all P < 0.05). This thesis has evaluated the feasibility and efficacy of the PULSE Program and highlighted the potential of self-administered, gender-tailored and multi-component lifestyle interventions for T2DM prevention in men at high-risk for the disease. The information presented within this thesis has important implications for T2DM prevention research and practice, as effective interventions that are pragmatic, scalable, and gender-targeted for men are urgently required to combat the rising prevalence of T2DM.
- Subject
- type 2 diabetes mellitus; diet; physical activity; obesity; overweight; weight loss; diabetes prevention; thesis by publication
- Identifier
- http://hdl.handle.net/1959.13/1309784
- Identifier
- uon:21942
- Rights
- Copyright 2015 Elroy Joseph Aguiar
- Language
- eng
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Abstract | 215 KB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Thesis | 7 MB | Adobe Acrobat PDF | View Details Download |