title: Blood magnesium, and the interaction with calcium, on the risk of high-grade prostate cancer.
abstract: BACKGROUND
  Ionized calcium (Ca) and magnesium (Mg) compete as essential messengers to regulate cell proliferation and inflammation. We hypothesized that inadequate Mg levels, perhaps relative to Ca levels (e.g. a high Ca/Mg ratio) are associated with greater prostate cancer risk.
  
  
  METHODS
  In this biomarker sub-study of the Nashville Men's Health Study (NMHS), we included 494 NMHS participants, consisting of 98 high-grade (Gleason≥7) and 100 low-grade cancer cases, 133 prostate intraepithelial neoplasia (PIN) cases, and 163 controls without cancer or PIN at biopsy. Linear and logistic regression were used to determine associations between blood Ca, Mg, and the Ca/Mg ratio across controls and case groups while adjusting for potential confounding factors.
  
  
  RESULTS
  Serum Mg levels were significantly lower, while the Ca/Mg ratio was significantly higher, among high-grade cases vs. controls (p = 0.04, p = 0.01, respectively). Elevated Mg was significantly associated with a lower risk of high-grade prostate cancer (OR = 0.26 (0.09, 0.85)). An elevated Ca/Mg ratio was also associated with an increased risk of high-grade prostate cancer (OR = 2.81 (1.24, 6.36) adjusted for serum Ca and Mg). In contrast, blood Ca levels were not significantly associated with prostate cancer or PIN.Mg, Ca, or Ca/Mg levels were not associated with low-grade cancer, PIN, PSA levels, prostate volume, or BPH treatment.
  
  
  CONCLUSIONS
  Low blood Mg levels and a high Ca/Mg ratio were significantly associated with high-grade prostate cancer. These findings suggest Mg affects prostate cancer risk perhaps through interacting with Ca.
authors.affiliation: Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America. qi.dai@vanderbilt.edu
authors.forename: Qi
authors.initials: Q
authors.lastname: Dai
authors.forename: Saundra S
authors.initials: SS
authors.lastname: Motley
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Smith
authors.forename: Raoul
authors.initials: R
authors.lastname: Concepcion
authors.forename: Daniel
authors.initials: D
authors.lastname: Barocas
authors.forename: Susan
authors.initials: S
authors.lastname: Byerly
authors.forename: Jay H
authors.initials: JH
authors.lastname: Fowke
mesh_terms: D000368:Aged; D002118:Calcium / Q000097:blood*; D006801:Humans; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D019048:Prostatic Intraepithelial Neoplasia / Q000097:blood / Q000473:pathology; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology*; D012307:Risk Factors
chemical_list: D008274:Magnesium; D002118:Calcium