Background

Cardiovascular disease (CVD) and diabetes account for one-third of the mortality difference between African American and white patients. We evaluated the effect of a CVD risk reduction intervention in African Americans with diabetes.

Methods

We randomized 359 African Americans with type 2 diabetes to receive usual care or a nurse telephone intervention. The 12-month intervention provided monthly self-management support and quarterly medication management facilitation. Coprimary outcomes were changes in systolic blood pressure (SBP), hemoglobin A1c (HbA1c), and low-density lipoprotein cholesterol (LDL-C) over 12 months. We estimated between-intervention group differences over time using linear mixed-effects models. The secondary outcome was self-reported medication adherence.

Results

The sample was 72% female; 49% had low health literacy, and 37% had annual income <$10,000. Model-based estimates for mean baseline SBP, HbA1c, and LDL-C were 136.8 mm Hg (95% CI 135.0-138.6), 8.0% (95% CI 7.8-8.2), and 99.1 mg/dL (95% CI 94.7-103.5), respectively. Intervention patients received 9.9 (SD 3.0) intervention calls on average. Primary providers replied to 76% of nurse medication management facilitation contacts, 18% of these resulted in medication changes. There were no between-group differences over time for SBP (P = .11), HbA1c (P = .66), or LDL-C (P = .79). Intervention patients were more likely than those receiving usual care to report improved medication adherence (odds ratio 4.4, 95% CI 1.8-10.6, P = .0008), but adherent patients did not exhibit relative improvement in primary outcomes.

Conclusions

This intervention improved self-reported medication adherence but not CVD risk factor control among African Americans with diabetes. Further research is needed to determine how to maximally impact CVD risk factors in African American patients.