Atherosclerotic cardiovascular disease (ASCVD) was the main cause of death in Germany in 2021, with major risk factors (ie, hypertension, diabetes, dyslipidaemia, obesity and certain lifestyle factors) being highly prevalent. Preventing ASCVD by assessment and modification of these risk factors is an important challenge for general practitioners. This study aims to systematically review and synthesise recent recommendations of national and international guidelines regarding the primary prevention of ASCVD in adults in primary care.

We will conduct a systematic review of clinical practice guidelines (CPGs) to evaluate primary prevention strategies for ASCVD. CPGs will be retrieved from MEDLINE and the Turning Research Into Practice database, guideline-specific databases and websites of guidelines-producing societies, with searches limited to publications from 2016 onwards. We will include CPGs in English, Spanish, German or Dutch languages that provide evidence-based recommendations for ASCVD prevention. The study population will include adults without diagnosed ASCVD. Two independent reviewers will assess guideline eligibility and quality by means of the mini-checklist MiChe, and extract study characteristics and relevant recommendations for further consistency analysis. A third reviewer will resolve disagreements. Findings will be presented as a narrative synthesis and in tabular form.

This review does not require ethical approval. Our systematic review will inform the CPG of the German College of General Practitioners and Family Physicians on the primary prevention of ASCVD. The review results will also be disseminated through publications in peer-reviewed journals and presentations at local, national and international conferences.

CRD42023394605.

To determine the feasibility of a definitive trial of metformin to prevent type 2 diabetes in the postnatal period in women with gestational diabetes.

A multicentre, placebo-controlled, double-blind randomised feasibility trial with qualitative evaluation.

Three inner-city UK National Health Service hospitals in London.

Pregnant women with gestational diabetes treated with medication.

2 g of metformin (intervention) or placebo (control) from delivery until 1 year postnatally.

Rates of recruitment, randomisation, follow-up, attrition and adherence to the intervention.

Preliminary estimates of glycaemic effects, qualitative exploration, acceptability of the intervention and costs.

Out of 302 eligible women, 57.9% (175/302) were recruited. We randomised 82.3% (144/175) of those recruited, with 71 women in the metformin group and 73 women in the placebo group. Of the participants remaining in the study and providing any adherence information, 54.1% (59/109) took at least 75% of the target intervention dose; the overall mean adherence was 64% (SD 33.6). Study procedures were found to be acceptable to women and healthcare professionals. An increased perceived risk of developing type 2 diabetes, or a positive experience of taking metformin during pregnancy, encouraged participation and adherence to the intervention. Barriers to adherence included disruption to the medication schedule caused by the washout periods ahead of each study visit or having insufficient daily reminders.

It is feasible to run a full-scale definitive trial on the effectiveness of metformin to prevent type 2 diabetes in women with gestational diabetes, during the early postnatal period. Adherence and engagement with the study could be improved with more regular reminders and potentially the addition of ongoing educational or peer support to reinforce messages around type 2 diabetes prevention.

ISRCTN20930880.