Abstract

Introduction: In Aotearoa New Zealand, Pacific peoples, including Tongans, experience disproportionately high rates of Type 2 Diabetes (T2D) and related complications, such as cardiovascular disease and renal failure. Traditional, generalized T2D management strategies often fail to account for cultural context, language barriers, and community-specific needs, resulting in persistent health inequities and delayed engagement with advanced technologies. There is an urgent need for innovative, culturally appropriate, and community-led interventions to improve long-term glycaemic outcomes.

Aim: To determine the impact of a novel intervention combining Continuous Glucose Monitoring (CGM) devices with structured cultural wrap-around support on medium-term glycaemic control and other T2D biomarkers in Tongan adults living with high-risk T2D.

Methods: This was a single-arm, prospective pilot intervention study. Twenty-two Tongan adults with poorly controlled T2D (HbA1c ≥ 60 mmol/mol) were recruited from primary care clinics. The intervention spanned six months and involved: (1) four weeks of CGM wear at baseline, (2) a two-week CGM wear period at the three-month follow-up, and (3) integrated, wrap-around care delivered by a Tongan kaiāwhina (support health worker). The kaiāwhina's role was critical, providing care and health education in a culturally resonant context and language, serving as a trusted intermediary between clinical data and patient understanding. Clinical outcomes (HbA1c, lipids, estimated Glomerular Filtration Rate [eGFR], Urinary Albumin-to-Creatinine Ratio [UACR]) and self-management behaviors (Diabetes Management Self-Efficacy Questionnaire [DMSQ] scores) were measured at baseline, 3, and 6 months. The study received full ethical approval from the University of Waikato Human Research Ethics Committee.

Results: Nineteen participants successfully completed the study through to 6 months. Mean (±SD) HbA1c significantly decreased from 83.6 ± 19.9 mmol/mol at baseline to 69.7 ± 14.1 mmol/mol at 3 months with reductions maintained at 6 months. No significant reductions in lipids or renal function were observed. DMSQ scores increased from 4.9 ± 0.8 to 6.0 ± 0.9.While the average reduction in lipids and improvement in renal function biomarkers (eGFR, UACR) were not statistically significant over the six-month period, the participants demonstrated a statistically significant improvement in self-efficacy, with mean DMSQ scores increasing from 4.9 ± 0.8 to 6.0 ± 0.9.

Discussion: The use of visual, real-time CGM data, when intentionally paired with culturally grounded support from a trusted kaiāwhina, demonstrated a substantial and clinically relevant improvement in glycaemic control in a high-risk Tongan population. The high retention rate and significant improvement in DMSQ scores further suggest that this model successfully addressed cultural and access barriers, enhancing health literacy and self-management confidence. Culturally tailored, technology-supported interventions offer a viable pathway to support Tongan adults with understanding, optimizing, and managing T2D, and should be considered for wider implementation across indigenous communities.