Adults aged 60 years and older with type 2 diabetes living in nursing homes may experience difficulty participating in conventional exercise programs because of frailty, mobility limitations, or chronic health conditions. This randomized controlled trial compares three 12-week non-pharmacological interventions for glycemic management: neuromuscular electrical stimulation (NMES), supervised combined aerobic and resistance exercise, and a structured health literacy intervention. Participants will be randomly assigned to one of the three groups. The primary outcome is weekly mean fasting capillary glucose. Secondary outcomes include health-related quality of life, treatment satisfaction, adherence, and safety. The study aims to identify feasible and clinically relevant strategies for improving diabetes management in institutionalized older adults.

This randomized controlled trial investigates the comparative effectiveness of three non-pharmacological strategies for glycemic management in institutionalized older adults with type 2 diabetes mellitus living in nursing homes and long-term care facilities in Portugal.

Older adults residing in institutional settings frequently present with reduced mobility, frailty, multimorbidity, and reduced participation in conventional exercise programs. These factors contribute to impaired glycemic control and increased risk of diabetes-related complications. Although exercise is recommended as a core component of diabetes management, implementing structured exercise programs in institutionalized older populations may be challenging because of physical limitations, reduced functional capacity, and low adherence.

Neuromuscular electrical stimulation (NMES) has been proposed as a potential alternative or adjunctive intervention for individuals with limited tolerance to conventional exercise. By eliciting involuntary muscle contractions, NMES may promote metabolic and muscular adaptations associated with improved glucose regulation while requiring lower physical demand from participants. However, evidence regarding its effectiveness in institutionalized older adults remains limited.

This study compares NMES, supervised combined aerobic and resistance exercise, and a structured health literacy intervention focused on diabetes self-management and healthy behaviors. The inclusion of an educational comparator allows exploration of the relative contribution of physiological and behavioral approaches to glycemic management.

The trial is designed to evaluate the feasibility, acceptability, and potential clinical effectiveness of these interventions in real-world long-term care settings. The findings may contribute to the development of more accessible and adaptable non-pharmacological strategies for older adults with functional limitations and reduced exercise capacity.

Inclusion Criteria:

• Confirmed diagnosis of type 2 diabetes mellitus.
• Age 60 years or older.
• Resident in a nursing home or similar long-term care facility in Portugal.
• Able to understand study procedures and provide informed consent.
• Stable antidiabetic medication regimen for at least 12 weeks before enrollment.

Exclusion Criteria:

• Severe cognitive impairment or inability to provide informed consent.
• Acute or unstable medical condition making participation unsafe.
• Contraindications to moderate-intensity exercise.
• Implanted electronic devices (e.g., pacemaker, implantable cardioverter-defibrillator).
• Skin lesions or dermatological conditions preventing safe electrode placement.
• Any condition judged by the clinical team to preclude safe participation.

De-identified individual participant data underlying the results reported in publications arising from this trial will be shared, including demographic variables, baseline characteristics, intervention allocation, outcome data, and statistical analysis datasets.

Beginning 6 months after publication of the primary results and ending 5 years after publication.

Access will be provided to researchers who submit a methodologically sound proposal. Requests will be reviewed by the study investigators. Data will be shared after approval, subject to ethical and legal requirements, and after signing a data access agreement.

Outcome assessors will remain blinded to group allocation throughout data collection. Participants and intervention providers cannot be blinded due to the nature of the interventions. Data analysts will also remain blinded to coded group allocation until completion of the primary analysis.