IntroductionThis randomized controlled trial investigated community-clinical intervention strategies for a Mexican American population who had not demonstrated control of their diabetes. We tested a control program (Salud y Vida 1.0) supporting diabetes management versus an enhanced version (Salud y Vida 2.0) for reductions in HbA1c at 12 months.Research design and methodsAdults with uncontrolled diabetes (n=353) were enrolled if they had an HbA1c≥9.0% during a program or doctor’s visit between 6 and 36 months of their receipt of SyV 1.0 services, were patients at one of two clinics in local counties, and had an HbA1c≥8.0% at SyV 2.0 baseline enrollment. The control and intervention arms were coordinated by community health workers and the intervention arm included the control program enhanced with medication therapy management; behavioral health services; peer-led support groups; and additional community-based lifestyle programs also open to the family.ResultsAt 12 months, both study arms improved HbA1c (mean, (CI), Control (−0.47 (-0.74 to –0.20)) and intervention (−0.48 (-0.76 to –0.19)). The intervention group maintained HbA1c levels after month 6, whereas control group HbA1c levels slightly increased (adjusted mean from 9.83% at month 6%–9.90% at month 12). Also, HbA1c was examined by level of participant engagement. The high engagement group showed a decreasing trend over the study period, while control and lower engagement groups failed to maintain HbA1c levels at month 12.ConclusionsImproved HbA1c was found among a population that had not demonstrated diabetes management prior; however, mean HbA1c values were above clinical guideline recommendations. The randomized control trial findings provide additional evidence that extended time and intervention supports may be needed for populations experiencing inequities in social determinants of health.Trial registration numberNCT04035395.