Cost-effectiveness analysis of recruitment strategies in a large diabetes prevention trial conducted across two sites in Sydney, Australia.

BACKGROUND: Diabetes prevention trials require large samples and community-based recruitment, which can be protracted and expensive. We analysed the cost-effectiveness of recruitment strategies used in a randomised placebo-controlled supplement trial in adults with prediabetes and overweight or obesity conducted in Sydney, Australia. METHODS: Recruitment strategies included advertising through local radio stations and newspapers, television news coverage, online advertising and editorials, advertising in and referral from primary care settings, university- and hospital-based advertising, and attending or hosting local events. For each strategy, the number of expressions of interest, screenings booked, and randomised participants were collated. The percentage contribution from each strategy, overall cost, and cost per participant were calculated. RESULTS: Of 4498 expressions of interest, 551 (12%) were eligible for onsite screening and 401 (9%) were randomised. Recruitment costs totalled AU$218,501, averaging AU$545 per participant. The recruitment strategy was recorded for 49% who expressed interest in the trial, and for 75% randomised into the trial. From these data, advertising on local radio stations was the most cost-effective strategy, contributing 46% of participants at AU$286 per participant, then advertising in and referral from primary care settings (57 participants [19%], AU$1438 per participant). The least cost-effective strategy was television news coverage, which was not targeted to the Sydney-based audience, contributing only six participants (AU$10,000 per participant). CONCLUSION: Radio advertising and recruitment through healthcare were the most effective recruitment strategies in this trial. Recruitment strategies should be location-specific and appropriate for the target population, prioritising low-effort high-yield strategies. Trial investigators should seek opportunities for free advertising.

A Qualitative Process Evaluation of Participant Experiences in a Feasibility Randomised Controlled Trial to Reduce Indulgent Foods and Beverages.

There is a growing interest in the effects of ultra-processed/energy-dense nutrient-poor foods on health outcomes, and few interventions to reduce their consumption have been tested. We tested a simple intervention to help people reduce the indulgences they consume (energy-dense nutrient-poor (EDNP) foods). Herein, we report the qualitative findings to understand how participants reduced their consumption by exploring intervention fidelity and the factors affecting consumption. We conducted a qualitative descriptive study of 23 adults who had taken part in a feasibility randomised controlled trial that asked participants to say no to seven indulgences/week and record what they said no to. Data were collected using face-to-face semi-structured interviews and analysed thematically. A total of 23 adults with an average BMI of 30.8 kg/m2 took part. Participants liked the term indulgence, as they could apply it to their normal dietary intake and make small changes. They found self-monitoring what they said no to helpful and reported that emotional eating and habits affected consumption. They had difficulty overcoming these. As most people are consuming too many foods that are EDNP, this simple intervention of "Say No" seven times/week has the potential to be developed as a public health campaign.

Differences in weight loss outcomes for males and females on a low-carbohydrate diet: A systematic review.

It has been widely demonstrated that there are a broad range of individual responses to all weight management regimens, often masked by reports of the mean. Identifying features of responders and non-responders to weight loss regimens enables a more tailored approach to the provision of weight management advice. Low-carbohydrate diets are currently popular, and anecdote suggests that males are more successful at losing weight using this approach. This is feasible given the physiological and socio-psychological differences between the genders. We analysed the extent and variation in weight change for males and females separately through a systematic search for all low-carbohydrate diet trials published since 1985. Very few studies compared weight loss outcomes by gender and, of those that did, most lacked supporting data. The majority of studies reported no gender difference but when a gender difference was found, males were more frequently reported as losing more weight than females on a low-carbohydrate diet. The lack of gender stratification in weight loss trials is concerning, as there are a range of gender-based factors that affect weight loss outcomes. This study highlights the importance of examining weight change for males and females separately, since as failure to do so may mask any potential differences, which, if detected, could assist with better weight loss outcomes.

Can a Higher Protein/Low Glycemic Index vs. a Conventional Diet Attenuate Changes in Appetite and Gut Hormones Following Weight Loss? A 3-Year PREVIEW Sub-study.

Background: Previous research showed that weight-reducing diets increase appetite sensations and/or circulating ghrelin concentrations for up to 36 months, with transient or enduring perturbations in circulating concentrations of the satiety hormone peptide YY. Objective: This study assessed whether a diet that is higher in protein and low in glycemic index (GI) may attenuate these changes. Methods: 136 adults with pre-diabetes and a body mass index of ≥25 kg/m2 underwent a 2-month weight-reducing total meal replacement diet. Participants who lost ≥8% body weight were randomized to one of two 34-month weight-maintenance diets: a higher-protein and moderate-carbohydrate (CHO) diet with low GI, or a moderate-protein and higher-CHO diet with moderate GI. Both arms involved recommendations to increase physical activity. Fasting plasma concentrations of total ghrelin and total peptide YY, and appetite sensations, were measured at 0 months (pre-weight loss), at 2 months (immediately post-weight loss), and at 6, 12, 24, and 36 months. Results: There was a decrease in plasma peptide YY concentrations and an increase in ghrelin after the 2-month weight-reducing diet, and these values approached pre-weight-loss values by 6 and 24 months, respectively (P = 0.32 and P = 0.08, respectively, vs. 0 months). However, there were no differences between the two weight-maintenance diets. Subjective appetite sensations were not affected by the weight-reducing diet nor the weight-maintenance diets. While participants regained an average of ~50% of the weight they had lost by 36 months, the changes in ghrelin and peptide YY during the weight-reducing phase did not correlate with weight regain. Conclusion: A higher-protein, low-GI diet for weight maintenance does not attenuate changes in ghrelin or peptide YY compared with a moderate-protein, moderate-GI diet. Clinical Trial Registry: ClinicalTrials.gov registry ID NCT01777893 (PREVIEW) and ID NCT02030249 (Sub-study).

Effects of α-Cyclodextrin on Cholesterol Control and Hydrolyzed Ginseng Extract on Glycemic Control in People With Prediabetes: A Randomized Clinical Trial.

Importance: Effective strategies for preventing type 2 diabetes are needed. Many people turn to complementary medicines, but there is little well-conducted scientific evidence to support their use. Objective: To assess the efficacy of α-cyclodextrin for cholesterol control and that of hydrolyzed ginseng for glycemic control in people with prediabetes and overweight or obesity. Design, Setting, and Participants: This 6-month double-blind, placebo-controlled, randomized clinical trial, with a 2 × 2 factorial design, was conducted between July 2015 and October 2018 at 2 locations in Sydney, Australia. Eligible participants were aged 18 years or older, had a body mass index (weight in kilograms divided by height in meters squared) of 25 or higher, and had prediabetes within 6 months of study entry according to the American Diabetes Association guidelines. Data analysis was performed from May to August 2019. Interventions: Participants were randomized to 1 of 4 groups to take active or placebo versions of each supplement (α-cyclodextrin plus hydrolyzed ginseng, α-cyclodextrin plus placebo, placebo plus hydrolyzed ginseng, or placebo plus placebo) for 6 months. All participants received dietetic advice for weight loss. Main Outcomes and Measures: The primary outcomes were the differences in total cholesterol and fasting plasma glucose between groups after 6 months. The primary analysis used the intention-to-treat principle. Multiple predetermined subsample analyses were conducted. Results: A total of 401 participants were eligible for the study (248 women [62%]; mean [SD] age, 53.5 [10.2] years; mean [SD] body mass index, 34.6 [6.2]). One hundred one patients were randomized to receive α-cyclodextrin plus hydrolyzed ginseng, 99 were randomized to receive α-cyclodextrin plus placebo, 101 were randomized to receive placebo plus hydrolyzed ginseng, and 100 were randomized to receive placebo plus placebo. For 200 participants taking α-cyclodextrin compared with 201 participants taking placebo, there was no difference in total cholesterol after 6 months (-1.5 mg/dL; 95% CI, -6.6 to 3.5 mg/dL; P = .51). For 202 participants taking hydrolyzed ginseng compared with 199 participants taking placebo, there was no difference in fasting plasma glucose after 6 months (0.0 mg/dL; 95% CI, -1.6 to 1.8 mg/dL; P = .95). Use of α-cyclodextrin was associated with constipation (16 participants vs 4 participants; P = .006) and cough (8 participants vs 1 participant; P = .02). Use of hydrolyzed ginseng was associated with rash and pruritus (13 participants vs 2 participants; P = .006). Only 37 of 401 participants (9.2%) experienced these adverse events. Conclusions and Relevance: Although they are safe for use, there was no benefit found for either α-cyclodextrin for cholesterol control or hydrolyzed ginseng for glycemic control in people with prediabetes and overweight or obesity. Trial Registration: Australian New Zealand Clinical Trials Registry Identifier: ACTRN12614001302640.

Effects of alpha-cyclodextrin on cholesterol control and Compound K on glycaemic control in people with pre-diabetes: Protocol for a Phase III randomized controlled trial.

The prevalence of pre-diabetes and of type 2 diabetes mellitus is increasing. Preventing disease progression is important to improve outcomes. Natural products are becoming popular alternatives to pharmaceutical products for preventative health and treatment of disease; however, the evidence to support the use of natural alternatives for pre-diabetes and type 2 diabetes is lacking. Two such natural medicines include alpha-cyclodextrin (marketed as FBCx), a fibre derived from corn starch that has been found to bind triglycerides in the intestines to prevent its absorption, aiding weight maintenance and lipid control, and hydrolysed ginseng extract (marketed as GINST15), a formula containing high amounts of Compound K, a metabolite of ginsenosides thought to be an active ingredient contributing to the anti-hyperglycaemic effects of ginseng. This paper describes the rationale and design of a 12-month randomized controlled trial to investigate the metabolic effects of these two products in people with pre-diabetes and overweight or obesity. A total of 400 participants will be randomized to one of four groups (FBCx + GINST15, FBCx + placebo, placebo + GINST15, placebo + placebo) for 6 months, followed by 6 months of follow-up. Participants will also receive lifestyle advice for healthy eating and weight loss. Data collected during the trial will include weight, waist circumference, body composition and blood pressure. Blood samples will also be collected to measure lipid profile and glycaemia. If the products are found to improve lipid and glucose levels, it will provide evidence for their use in people with pre-diabetes to help reduce the risk of progression to type 2 diabetes.