This study aims to explore: (1) the relationship between lifestyle factors (eating, movement behaviour, sleep and stress) and glycaemic profile, and (2) the feasibility of delivering lifestyle intervention through the proposed mHealth strategy.

A 2-week observational period, followed by a 8-week parallel 2-arm, single-centre, randomized controlled trial (RCT) study involving 60-80 multi-ethnic healthy women (Chinese, Malay, Indian, others) subjects aged between 21 and 45 years who had a previous diagnosis of Gestational diabetes mellitus (GDM).

Type 2 diabetes is the most common type of diabetes and if left untreated or is ill-managed, can lead to detrimental long-term health problems such as heart disease, kidney disease and stroke. Type 2 diabetes is often related to lifestyle and develops over time; with proper interventions, it could be avoided in some cases. GDM stands for Gestational Diabetes Mellitus and can occur in some pregnant women, usually from week 24 of pregnancy. Women with a history of GDM have also been connected to a lifetime risk of developing type 2 diabetes and cardiovascular disease. In Singapore, it is estimated that 4 in 10 women with GDM could develop pre-diabetes or diabetes within five years of their pregnancy. Therefore, postpartum follow-up is essential in early detection of, preventing or delaying the development of Type 2 diabetes in this group.

The study hypothesize that there is an association between glycaemic profile and daily lifestyle (i.e. eating behavior, physical activity sleep and stress) among women with a history of GDM. The study also hypothesize that it is feasible to adopt a holistic approach and introduce a personalized mHealth intervention to promote metabolic and mental health among women with a history of GDM. The study is a parallel 2-arm, single-centre randomized controlled trial based on 1:1 allocation ratio.

The study arms are; Group 1 (Intervention group) and Group 2 (Control group). The study will begin with baseline data collection (anthropometric measures, body composition, biochemistry tests, questionnaires) and 14-day observation of interstitial glucose and lifestyle (diet, physical activity, sleep and stress). Every subject, irrespective of their group allocation, will use Oura ring and Oura App throughout the study duration. Every subject randomized to Group 1( Intervention group) will additionally receive HealthifySG App which provides personalized lifestyle interventions that last for 4 weeks. Lifestyle recommendations (targeting diet, physical activity, sleep and stress) will be delivered by study team member through the HealthifySG App on a weekly basis. On the contrary, subjects randomized to Group 2 (Control group) will not receive the HealthifySGApp and lifestyle interventions during this period. Subsequently, both groups will be followed-up for 4 weeks.

The overall aim of the REVERSE DIABETES programme is three pronged: (1) to be more proactive in screening to identify women with a history of GDM in polyclinics and the community, (2) to explore the potential of mobile health (mHealth) strategies to engage these women and deliver holistic and personalized interventions for promoting metabolic health and mental wellbeing, and (3) to engage primary care physicians to use mHealth if proven acceptable and useful in the long term follow up of these GDM women in the polyclinics and communities. We hope to optimize the preventive measures within the community in the long term.

Based on the above considerations, conducting a pilot randomized controlled trial would allow the study team to: (1) better understand the women's lifestyle behaviours and preferences, (2) validate the devices used for measuring lifestyle behaviours, (3) examine the feasibility of the proposed mHealth intervention and personalized lifestyle recommendation, (4) evaluate the initial effects and cost-effectiveness of the intervention, and (5) identify other benefits and potential risk of the proposed idea.

Inclusion Criteria:

• Healthy female volunteers (age 21-45 years)
• A history of GDM in the past 5 years
• Not planning to conceive during the study period
• Not performing full breastfeeding during the study period
• Own a smart phone(mobile phone) compatible with study App (Android v10 and above)
• Proficient in English language
• Plan to stay in Singapore for the next 1 year
• Willing to comply to study protocol
• Able to provide a written informed consent

Exclusion Criteria:

• Current and/or previous diagnosis of diabetes except GDM
• Currently pregnant
• Given birth within last 12 weeks
• Following special diet or dietary restriction
• Experiencing severely limited mobility (e.g. wheelchair bound, need walking aid etc.)
• Diagnosed with malnutrition, eating disorder, severe insomnia
• Diagnosed with cancers, unstable heart related diseases, severe kidney disease
• Diagnosed with severe unstable mental conditions, dementia or cognitive impairment
• Alcohol or drug abuse
• Medications known to influence glucose metabolism e.g. peroral corticosteroids

Healthy women volunteers who has given birth previously and with a history of GDM within the last 5 years (Post partum 13 weeks and beyond).

60-80 female subjects will be randomized to either Group 1 (Intervention group) or Group 2 (Control group) based on 1:1 allocation. HealthifySG App will only be installed on the phones of subjects for Group 1(Intervention group).