Abstract 10374: Dietary Intervention to Reduce Fat Intake Does Not Result in Lower Incident Carotid Artery Disease: The Women’S Health Initiative Diet Modification Trial
Introduction: The Women’s Health Initiative (WHI) previously reported that a diet aimed at reducing total fat intake, while increasing fruit vegetable and grain intake, did not result in a significant reduction in incident stroke. Since the diagnosis and treatment of carotid artery disease may reduce the rate of stroke, the aim of this study was to determine whether the same diet intervention was associated with incident carotid artery disease.
Methods: Participants were 48,835 postmenopausal women aged 50 to 79 years who were randomly assigned to the intervention or comparison groups in the WHI Dietary Modification Trial. The intervention included intensive behavior modification designed to reduce fat intake to 20% of total calories and increase intake of fruits and vegetables to 5 servings/day and grains to at least 6 servings/day. The comparison group received diet-related education materials. The outcome measure of incident carotid artery disease was defined as either symptomatic or resulted in/or occurred during hospitalization.
Results: After 8.3 years of follow-up, there were 297 incident events. Compared to the comparison group, women assigned to the intervention group did not have a different risk for incident carotid disease (HR: 1.08, 95% CI: 0.9 - 1.4). In secondary analysis, there was no significant effect of the intervention on the risk for incident carotid disease during the four years of post-intervention follow-up (1.24, 0.9 - 1.7). In subgroup analyses, there was a suggestion of an interaction between randomization group and history of hypertension (p-int = 0.07). Specifically, among those with hypertension, the intervention was associated with a 29% higher risk for incident carotid disease, while there was a 24% lower risk among those who did not report such a history. Among the intervention group, and compared to the mean caloric intake in the comparison group, the risk for incident carotid disease was highest for those who reported consuming the lowest calorie intake (1.77, 1.3 - 2.4; p-trend = 0.03). Discussion: Among postmenopausal women, a dietary intervention aimed at reducing total calories from fat, as well as increasing fruit, vegetable and grain intake, did not significantly change the risk for incident carotid artery disease.
- © 2013 by American Heart Association, Inc.