Irreversible Deterioration of Cortical and Trabecular Microstructure Associated With Breastfeeding

Åshild Bjørnerem, Ali Ghasem-Zadeh, Xiaofang Wang, Minh Bui, Susan P. Walker, Roger Zebaze, Ego Seeman

Research output: Contribution to journalArticleResearchpeer-review

37 Citations (Scopus)

Abstract

Estrogen deficiency associated with menopause is accompanied by an increase in the rate of bone remodeling and the appearance of a remodeling imbalance; each of the greater number of remodeling transactions deposits less bone than was resorbed, resulting in microstructural deterioration. The newly deposited bone is also less completely mineralized than the older bone resorbed. We examined whether breastfeeding, an estrogen-deficient state, compromises bone microstructure and matrix mineral density. Distal tibial and distal radial microarchitecture were quantified using high-resolution peripheral quantitative computed tomography in 58 women before, during, and after breastfeeding and in 48 controls during follow-up of 1 to 5 years. Five months of exclusive breastfeeding increased cortical porosity by 0.6% (95% confidence interval [CI] 0.3–0.9), reduced matrix mineralization density by 0.26% (95% CI 0.12–0.41) (both p < 0.01), reduced trabecular number by 0.22 per mm (95% CI 0.15–0.28), and increased trabecular separation by 0.07 mm (95% CI 0.05–0.08) (all p < 0.001). Relative to prebreastfeeding, at a median of 2.6 years (range 1 to 4.8) after cessation of breastfeeding, cortical porosity remained 0.58 SD (95% CI 0.48–0.68) higher, matrix mineralization density remained 1.28 SD (95% CI 1.07–1.49) lower, and trabeculae were 1.33 SD (95% CI 1.15–1.50) fewer and 1.06 SD (95% CI 0.91–1.22) more greatly separated (all p < 0.001). All deficits were greater than in controls. The results were similar at distal radius. Bone microstructure may be irreversibly deteriorated after cessation of breastfeeding at appendicular sites. Studies are needed to establish whether this deterioration compromises bone strength and increases fracture risk later in life.

Original languageEnglish
Pages (from-to)681-687
Number of pages7
JournalJournal of Bone and Mineral Research
Volume32
Issue number4
DOIs
Publication statusPublished - 1 Apr 2017
Externally publishedYes

Keywords

  • CORTICAL POROSITY
  • LACTATION
  • MATRIX MINERALIZATION
  • TRABECULAR BONE MICROARCHITECTURE

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