title: Correlation of estradiol, parathyroid hormone, interleukin-6, and soluble interleukin-6 receptor during the normal menstrual cycle.
abstract: Rodent models suggest that estradiol deficiency promotes bone loss through increasing interleukin-6 (IL-6) activity. However, it is controversial as to whether these findings are applicable to humans. To evaluate estradiol-mediated modulation of IL-6 activity in relation to bone metabolism in humans, we measured serum IL-6, soluble interleukin-6 receptor (sIL-6R), estradiol (E2), progesterone, luteinizing hormone, follicle-stimulating hormone, intact parathyroid hormone (PTH), serum and urine Ca, and bone biochemical markers (serum bone-specific alkaline phosphatase, osteocalcin, and serum and urine deoxypyridinoline [Dpd]) across one menstrual cycle for 211 women. Neither IL-6 nor sIL-6R levels differed between the follicular phase (FP) and the luteal phases (LP). However, IL-6 was negatively correlated with E2 during the FP (p =0.003). Furthermore, IL-6 correlated positively with serum Ca over the entire cycle (p = 0.0091. Serum Ca correlated positively with serum (p = 0.040) and urine (p = 0.006) Dpd. PTH was significantly higher during the FP than in the LP (p = 0.004). PTH was negatively related to E2 (p = 0.002), serum Ca (p < 0.001), and urine Ca (p = 0.036), whereas it was positively correlated with IL-6 (p = 0.027). These data demonstrate that IL-6 and PTH fluctuate with E2, and serum II-6 is associated with PTH levels during the menstrual cycle. However, the role of 11-6 in bone remodeling during the normal menstrual cycle remains to be determined.
authors.affiliation: Department of Pathology, School of Medicine and the Institute of Gerontology, University of Michigan, Ann Arbor 48109-0940, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Chiu
authors.forename: C D
authors.initials: CD
authors.lastname: Arnaud
authors.forename: J
authors.initials: J
authors.lastname: Ju
authors.forename: D
authors.initials: D
authors.lastname: Mayes
authors.forename: P
authors.initials: P
authors.lastname: Bacchetti
authors.forename: S
authors.initials: S
authors.lastname: Weitz
authors.forename: E T
authors.initials: ET
authors.lastname: Keller
mesh_terms: D000328:Adult; D015415:Biomarkers; D016723:Bone Remodeling; D002118:Calcium / Q000378:metabolism; D004958:Estradiol / Q000097:blood*; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008597:Menstrual Cycle; D010281:Parathyroid Hormone / Q000097:blood*; D019947:Receptors, Interleukin-6 / Q000097:blood*; D012995:Solubility
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D010281:Parathyroid Hormone; D019947:Receptors, Interleukin-6; D004958:Estradiol; D002118:Calcium