Abstract Body: Introduction: The Dietary Approaches to Stop Hypertension (DASH) diet was designed for its cardiovascular benefits but emphasizes higher carbohydrates. Its impact on glycemia in adults with impaired glycemic control is not well-characterized.

Hypothesis: A DASH-patterned grocery intervention will lower hemoglobin A1c (HbA1c) among adults with prediabetes.

Methods:
GoFresh randomized Black adults with high blood pressure (BP) (systolic BP 120 to <150 mmHg, diastolic BP <100 mmHg) living in urban food deserts around Boston, Massachusetts to 3 months of weekly delivered DASH-patterned groceries or three $500 stipends every 4 weeks for self-directed grocery shopping. HbA1c was measured at baseline and 3-months after the intervention phase. The primary outcome of this post-hoc analysis was the difference in 3-month difference in HbA1c between study groups by baseline prediabetes status (HbA1c ≥5.7%). Effects were modeled via generalized estimating equations with a three-way interaction term for time, study group, and prediabetes status. Secondary outcomes included changes in BP, body mass index, serum lipids, and urinary albumin-creatinine ratio.

Results:
Among 180 participants, 61 (34%) had HbA1c≥5.7% at baseline (Table 1). The effect of the intervention on differences in HbA1c was significantly different between those with and without prediabetes (P-interaction=0.006) (Figure 1). Among those with prediabetes, HbA1c changed by -0.08% (95%CI -0.14, -0.02) for the intervention group and by 0.04% (95%CI -0.02, 0.11) for the control group (difference-in-difference [DiD] -0.12%; 95%CI -0.21, -0.03). Among those without prediabetes, there was no significant difference in HbA1c changes between intervention groups (DiD 0.05%; 95%CI -0.01, 0.12). Similarly, the effect of the intervention on triglycerides was greater in the prediabetes group (difference-in-DiD: -0.32 log[mg/dL]; 95%CI -0.53, -0.12; P-interaction=0.002) (Table 2). No interaction effects were observed for other cardiometabolic markers.

Conclusion:
Beyond improving BP, providing DASH-patterned groceries significantly improved glycemia and triglyceride levels among Black adults with high BP and prediabetes. These results suggest that the GoFresh grocery ordering guidelines may be especially useful to improve cardiometabolic health among populations at higher risk for diabetes. Future work should evaluate whether this strategy can mitigate progression to diabetes among those with impaired glycemic control.