BACKGROUND
Prediabetes is the state of elevated blood glucose levels with glycaemic parameters above normal but below the (type 2) diabetes threshold. Prediabetes is considered a state of high risk for developing type 2 diabetes with yearly transition rate of 5%-10% to type 2 diabetes. There are almost 86 million adults with prediabetes in the United States alone. The world-wide prevalence of impaired glucose tolerance (IGT; a parameter of prediabetes) in 2010 was estimated to be 343 million (7.8%). Prediabetes is a global burden, with the International Diabetes Federation projecting an increase in prevalence of prediabetes to 471 million globally by 2035.
OBJECTIVE
Our objective was to evaluate the 1-year outcomes of the smart-phone delivered Low Carb Program for Prediabetes, a nutritionally focused, 12-session educational intervention for glycaemic control and weight loss for adults with prediabetes (i.e. a type 2 diabetes prevention program). The program reinforces carbohydrate restriction using behavioural techniques including goal setting, peer support, and behavioural self-monitoring.
METHODS
The study used a quasi-experimental research design comprised of an open-label, single-arm, pre-post intervention using a sample of convenience. We followed all of the 260 adults with prediabetes who had activated their referral to the program as a result of an NHS consultation between December 2018 and March 2019 and followed them for 12 months (N=260; mean age 44.7, SD 9.48 years; 36.1% (94/260) women; mean glycated haemoglobin A1c (HbA1c) 6.25%, SD 0.11%; mean body weight 77.1kg, SD 17.5kg; taking mean 0.41, SD 0.49 diabetes medications).
RESULTS
Of the 260 participants followed, 221 (85%) individuals reported outcomes at 12 months. 122 (46.9%) completed 80% or more of lessons of the program. Of the 260 participants with a starting HbA1c at or above the prediabetes threshold of 6.0%, 124 (49.6%) reduced their HbA1c to below the threshold. Over a third (33.8%, 88/260) of all participants lost at least 5% of their body weight. Overall, glycaemic control and weight loss improved, especially for participants who completed all modules of the program. For example, participants who engaged in at least 10 of the 12 weekly modules reduced their HbA1c from 6.3% to 5.8% (P<.001) and lost an average of 4.38kg or 5.4% of their body weight (P<.001).
CONCLUSIONS
A smart-phone delivered program that teaches a carbohydrate-reduced diet to adults with prediabetes with behaviour change support can be scalable and effective for glycaemic control, weight loss and can act as an engaging intervention for diabetes prevention.