title: Association between prolonged breastfeeding and bone mineral density and osteoporosis in postmenopausal women: KNHANES 2010-2011.
abstract: This study showed that a negative correlation between duration of breastfeeding and bone mineral density (BMD) in the lumbar spine and prolonged breastfeeding is an independent risk for osteoporosis in postmenopausal women. The present study suggests that postmenopausal women with a history of prolonged breastfeeding require more careful screening for osteoporosis.
  
  
  BACKGROUND
  Several studies suggest that breastfeeding and childbirth lead to maternal calcium loss and a decline in BMD. While the association between breastfeeding and BMD immediately after weaning is well-established, the effects of breastfeeding on postmenopausal women have been controversial. The aim of this study was to examine the effects of breastfeeding on bone mineral density (BMD) and the prevalence of osteoporosis in postmenopausal women.
  
  
  METHODS
  The present study was a cross-sectional survey based on the Korea National Health and Nutrition Examination Survey (KNHANES) 2010 and 2011 data. The association between breastfeeding and BMD and osteoporosis was examined in 1222 postmenopausal women.
  
  
  RESULTS
  The duration of breastfeeding and BMD in the lumbar spine showed a negative correlation. The association between duration of breastfeeding and BMD remained significant after adjustment for reproductive factors and other confounding factors (P = 0.008). However, the number of deliveries and age at the time of delivery did not correlate with BMD at any site after adjustment. Moreover, the prevalence of osteoporosis in postmenopausal women with a history of prolonged breastfeeding was significantly higher than that in women with a short history of breastfeeding (≥37 months, OR = 3.292; 95 % CI 1.485-7.299). The prevalence of lumbar spine fracture showed a significant increasing trend with the increase in the duration of breastfeeding.
  
  
  CONCLUSIONS
  Prolonged breastfeeding was significantly associated with low BMD in the lumbar spine and higher prevalence of osteoporosis. However, the number of deliveries or age at the time of childbirth did not influence BMD.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, South Korea.
authors.forename: I R
authors.initials: IR
authors.lastname: Hwang
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, South Korea.
authors.forename: Y K
authors.initials: YK
authors.lastname: Choi
authors.affiliation: Department of Preventive Medicine, Kyungpook National University School of Medicine, Daegu, South Korea.
authors.forename: W K
authors.initials: WK
authors.lastname: Lee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, South Korea.
authors.forename: J G
authors.initials: JG
authors.lastname: Kim
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, South Korea.
authors.forename: I K
authors.initials: IK
authors.lastname: Lee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, South Korea. sungwoocap@naver.com.
authors.forename: S W
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, South Korea. kpark@knu.ac.kr.
authors.forename: K G
authors.initials: KG
authors.lastname: Park
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D015519:Bone Density / Q000502:physiology*; D001942:Breast Feeding / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000503:physiopathology; D006306:Health Surveys; D006801:Humans; D007774:Lactation / Q000502:physiology*; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D056910:Republic of Korea / Q000453:epidemiology; D016103:Spinal Fractures / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors
keywords: Bone mineral density; Breastfeeding; Osteoporosis; Postmenopausal women