title: Bone Density Loss Is Associated With Blood Cell Counts.
abstract: Hematopoiesis depends on a supportive microenvironment. Preclinical studies in mice have demonstrated that osteoblasts influence the development of blood cells, particularly erythrocytes, B lymphocytes, and neutrophils. However, it is unknown whether osteoblast numbers or function impact blood cell counts in humans. We tested the hypothesis that men with low BMD or greater BMD loss have decreased circulating erythrocytes and lymphocytes and increased myeloid cells. We performed a cross-sectional analysis and prospective analysis in the Osteoporotic Fractures in Men (MrOS) study, a multisite longitudinal cohort study. A total of 2571 community-dwelling men (≥65 years) who were able to walk without assistance, did not have a hip replacement or fracture, and had complete blood counts (CBCs) at the third study visit were analyzed. Multivariable (MV)-adjusted logistic regression estimated odds of white blood cell (WBC) subtypes (highest and lowest quintile versus middle), and anemia (clinically defined) associated with BMD by DXA scan (at visit 3), annualized percent BMD change (baseline to visit 3), and high BMD loss (>0.5%/year, from baseline to visit 3) at the femoral neck (FN) and total hip (TH). MV-adjusted models included age, BMI, cancer history, smoking status, alcohol intake, corticosteroid use, self-reported health, thiazide use, and physical activity. At visit 3 greater TH BMD loss (per 1 SD) was associated with increased odds of anemia, high neutrophils, and low lymphocytes. Annualized BMD loss of >0.5% was associated with increased odds of anemia, high neutrophils, and low lymphocytes. Similar results were observed for FN BMD regarding anemia and lymphocytes. We conclude that community-dwelling older men with declining hip BMD over about 7 years had increased risks of anemia, lower lymphocyte count, and higher neutrophil count, consistent with preclinical studies. Bone health and hematopoiesis may have greater interdependency than previously recognized. © 2016 American Society for Bone and Mineral Research.
authors.affiliation: Division of Endocrinology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Rodrigo J
authors.initials: RJ
authors.lastname: Valderrábano
authors.affiliation: San Francisco Coordinating Center, California Pacific Medical Center, San Francisco, CA, USA.
authors.forename: Li-Yung
authors.initials: LY
authors.lastname: Lui
authors.affiliation: Division of Endocrinology, Stanford University School of Medicine, Stanford, CA, USA.|Palo Alto Veteran Affairs Health Care System, Palo Alto, CA, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Lee
authors.affiliation: San Francisco Coordinating Center, California Pacific Medical Center, San Francisco, CA, USA.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Cummings
authors.affiliation: Department of Medicine, Bone and Mineral Unit, Oregon Health and Science University, Portland, OR, USA.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Orwoll
authors.affiliation: Division of Endocrinology, Stanford University School of Medicine, Stanford, CA, USA.|Palo Alto Veteran Affairs Health Care System, Palo Alto, CA, USA.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Hoffman
authors.affiliation: Division of Endocrinology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Joy Y
authors.initials: JY
authors.lastname: Wu
mesh_terms: D000368:Aged; D001772:Blood Cell Count; D015519:Bone Density; D002452:Cell Count; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D008297:Male; D058866:Osteoporotic Fractures / Q000097:blood / Q000503:physiopathology
keywords: ANALYSIS/QUANTITATION OF BONE; BONE INTERACTORS; DISEASES AND DISORDERS OF/RELATED TO BONE; DXA; OSTEOIMMUNOLOGY; OSTEOPOROSIS