PC2027: History of Breastfeeding and Stroke Prevalence Among Parous Females: Findings from the National Health and Nutrition Examination Survey (NHANES), 1999-2012

Background: Stroke is the third leading cause of death for women in the United States, resulting in twice as many deaths as breast cancer. There is a known relationship between hypertension and stroke, as well as breastfeeding and hypertension. The objective of this study is to determine the association between a history of breastfeeding and stroke later in life among parous females. We hypothesized that a history of breastfeeding is associated with lower prevalence of stroke.

Methods: We used data from the 1999-2012 National Health and Nutrition Examination Survey (NHANES) questionnaires that asked about ever breastfeeding or ever having a stroke to perform the analysis. Our study population included parous females ages 20 years and older. Potential confounders included family poverty income ratio, education, parity, and age at first live birth. Potential effect measure modifiers of interest included race/ethnicity and age at time of survey. Multivariable logistic regression models were used to estimate the crude and adjusted prevalence odds ratios (OR) and 95% confidence intervals (CI) for the association between breastfeeding and stroke.

Results: The odds of stroke among those who ever breastfed were 0.68 times the odds of stroke among those who never breastfed (OR = 0.68, 95% CI: 0.55, 0.86; P < 0.01) (Table 1). Adjusting for education decreased the strength of the association but it remained moderately inverse (OR = 0.80, 95% CI: 0.63, 1.01; P = 0.06). In analyses stratified by age, the inverse association of breastfeeding status remained among those ages 20-64 years (OR = 0.69, 95% CI: 0.47, 1.00) but not among those 65 years and older (OR = 0.99, 95% CI: 0.73, 1.34) (Table 2). When stratified by race/ethnicity, in non-Hispanic Black females, the OR associating breastfeeding and stroke was 0.60 (95% CI: 0.40, 0.90), whereas the OR was 0.96 (95% CI: 0.72, 1.27) in non-Hispanic white females.

Conclusion: The results of this study support our hypothesis of an inverse association between ever breastfeeding a child and prevalence of stroke later in life in a nationally representative sample of parous females ages 20 years and older. When results were stratified by age, we observed a strong inverse association in those less than 65-years-old but a null association among those 65 years and older. As stroke has such large morbidity for females in the United States, risk reduction via promotion of breastfeeding during the reproductive years could have a large public health impact.