title: Mineral content of calcium and magnesium in the serum and longitudinal periodontal progression in Japanese elderly smokers.
abstract: OBJECTIVE
  Evidence from physiological and clinical studies regarding the mechanism by which calcium and magnesium are associated with periodontal disease, adjusted for smoking habits, is lacking. This longitudinal study evaluated the association of serum calcium levels and the calcium/magnesium (Ca/Mg) ratio with periodontal disease progression among smokers and non-smokers.
  
  
  METHODS
  A total of 309 subjects aged 73 years were included. Follow-up surveys were carried out every year for 6 years. After dividing subjects into smokers and non-smokers, multiple logistic regression analysis for men was performed to evaluate the relationship between the serum Ca/Mg ratio and periodontal disease progression. We used the 25th percentile of periodontal disease events for 6 years as the dependent variable and seven other variables, including quartiles for serum Ca/Mg ratios, as independent variables.
  
  
  RESULTS
  There was a clear dose-response relationship of Ca/Mg ratio quartiles for periodontal disease events among smokers. Significant differences in odds ratios in the first and second quartiles were seen compared with the fourth quartile (reference): 6.28 (p=0.014) and 5.96 (p=0.022), respectively. However, there was no significant dose-response relationship among non-smokers.
  
  
  CONCLUSIONS
  A low serum Ca/Mg ratio was significantly associated with periodontal disease progression in Japanese elderly smokers.
authors.affiliation: Department of Oral Health Science, Division of Preventive Dentistry, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan. akihiro@dent.niigata-u.ac.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshihara
authors.forename: Masanori
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Hideo
authors.initials: H
authors.lastname: Miyazaki
mesh_terms: D000368:Aged; D015519:Bone Density; D002118:Calcium / Q000097:blood*; D055113:Chronic Periodontitis / Q000097:blood / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008274:Magnesium / Q000097:blood*; D008297:Male; D016017:Odds Ratio; D012907:Smoking / Q000097:blood / Q000378:metabolism*; D018709:Statistics, Nonparametric
chemical_list: D008274:Magnesium; D002118:Calcium