Most patient chronic disease self-management interventions target single-disease outcomes. We evaluated the effect of a tailored hypertension self-management intervention on the unintended targets of glycosylated hemoglobin (HbA_1c) and low-density lipoprotein cholesterol (LDL-C).

We evaluated patients from the Veterans Study to Improve the Control of Hypertension, a 2-year randomized controlled trial. Patients received either a hypertension self-management intervention delivered by a nurse over the telephone or usual care. Although the study focused on hypertension self-management, we compared changes in HbA_1c among a subgroup of 216 patients with diabetes and LDL-C among 528 patients with measurements during the study period. Changes in these laboratory values over time were compared between the 2 treatment groups using linear mixed-effects models.

For the patients with diabetes, the hypertension self-management intervention resulted in a 0.46% reduction in HbA_1c over 2 years compared with usual care (95% confidence interval, 0.04%-0.89%; P=.03). For LDL-C, there was a minimal 0.9 mg/dL between-group difference that was not statistically significant (95% confidence interval, −7.3-5.6 mg/dL; P=.79).

There was a significant effect of the self-management intervention on the unintended target of HbA_1c,but not LDL-C. Chronic disease self-management interventions might have “spill-over” effects on patients' comorbid chronic conditions.