Abstract P267: Paradoxical Association Between Breastfeeding Duration and Hypertension in Later Years in Parous Korean Women: A Nationwide, Population-based Study

Abstract

Background: The World Health Organization (WHO) recommends exclusive breastfeeding from birth to 6 months, the introduction of nutritious complementary foods at 6 months and continued breastfeeding up to 2 years or above. A U-shaped association between duration of breastfeeding and systolic blood pressure (BP) or hypertension was reported. However, multiple studies have yielded inconsistent findings. Method: Among subjects who participated in the Korea National Health and Nutrition Examination Survey conducted in 2010-2012, a total of 5,011 parous female, aged over 19 years old were analyzed. Hypertension was defined based on JNC 8 guidelines, or a self-reported current use of antihypertensive medications. Based on the JNC 8 criteria, for patients 60 years of age or older who did not have diabetes or chronic kidney disease, a blood pressure goal of less than 150/90 mmHg was the target goal or diagnosis. The blood pressure goal of diagnosis and control is less than 140/90 mmHg for patients 18 to 59 years of age without major comorbidities, and those 60 years of age or older who had diabetes, chronic kidney disease, or both conditions. We divided the duration of breast feeding into none, less than 6 months, less than 1 year and more than 6 months, less than 2 years and more than 1 year, and more than 2 years. Results: The distribution of systolic and diastolic BP and hypertension prevalence showed U-shape pattern in non-obese women (BMI < 25 kg/m 2 ). Those who breastfed less than 6 months had the lowest blood pressure (123.7±1.1 mmHg for mean systolic BP and 74.2±0.7 mmHg for mean diastolic BP; P=0.06), as well as the lowest prevalence of hypertension (14.6%; P < 0.001) in non-obese women. With increasing duration of breastfeeding, no specific trend was observed in obese women. In non-obese women with BMI < 25 kg/m 2 , compared to women with duration of breast feeding less than 6 months, the odds of hypertension was significantly higher in women with breast feeding more than 2 years in women with [odds ratio (OR): 1.72, 95 % confidence interval (CI): 1.10-2.70], after adjusting for age, body mass index, smoking, drinking alcohol, exercise, income, and education. However, there was no significant association between duration of breastfeeding and hypertension control. Conclusion: Our findings suggest that longer duration of breastfeeding might not protect against hypertension in later ages. Previously,breast feeding could be helpful to mother after delivery to normalize her body weight, metabolic panel derangement, however, longer duration of breast feeding especially in non-obese women would not contribute to hypertension prevention. Further prospective studies are warranted to confirm this association.