In the pre-diabetic adult population, is there enough data to determine which will facilitate a greater impact on lowering A1C in a 3 and 6 month period of time, diet and exercise alone or diet, exercise and early initiation of metformin?: A narrative review

Pre-diabetes affects millions of adults and is a major risk factor for the development of type 2 diabetes mellitus. Early intervention is essential to improve glycemic control and prevent disease progression. This narrative review examines whether lifestyle modification alone (diet and exercise) or lifestyle modification combined with early initiation of metformin is more effective in reducing hemoglobin A1C over 3- and 6-month periods in adults with prediabetes.

A literature search was conducted using PubMed, Embase, Scopus, and CINAHL to identify systematic reviews and randomized controlled trials published between 2021 and 2026. Six studies met the inclusion criteria and evaluated the effects of lifestyle interventions, metformin therapy, or combination treatment on glycemic outcomes, diabetes prevention, and metabolic health. The evidence consistently demonstrated that lifestyle modification remains the cornerstone of pre-diabetes management and significantly reduces the risk of progression to type 2 diabetes mellitus while improving glycemic control. Metformin also showed meaningful benefits, particularly among younger adults, individuals with obesity, and those at higher risk for diabetes. Several studies found that combining metformin with lifestyle interventions resulted in greater reductions in diabetes progression, additional weight loss, and improvements in insulin sensitivity compared with lifestyle modification alone. Aerobic interval training and combined aerobic and resistance exercise were identified as the most effective exercise strategies.

Although the findings support the use of combined therapy in selected high-risk populations, limitations across the literature included small sample sizes, short follow-up periods, inconsistent adherence to interventions, and limited representation of diverse socioeconomic populations. As a result, individualized treatment decisions remain essential.

This presentation highlights current evidence to guide advanced practice providers in selecting evidence-based interventions for adults with pre-diabetes. Lifestyle modification should remain the first-line treatment, while early metformin initiation may be considered for patients with obesity, hypertension, or other significant risk factors when individualized assessment suggests additional benefit.

Aneta Krzeszowiec is a first-year Doctor of Nursing Practice student at Columbia University preparing to become a Family Nurse Practitioner, with subspecialty concentrations in Oncology and Women’s Health. She earned her Master of Science in Nursing from Columbia University and previously completed a Bachelor of Science in Bioscience with a minor in Business Management from Farmingdale State College. Inspired by serving as an interpreter and advocate for her Polish-speaking mother during medical appointments, Aneta is committed to providing culturally sensitive, patient-centered care and promoting disease prevention in the primary care setting.