title: Periodontal conditions in an elderly Japanese population influenced by smoking status and serum immunoglobulin G2 levels.
abstract: BACKGROUND
  A Japanese population residing in the same area may be suitable for evaluation of the association among IgG subclass levels, smoking status, and periodontal disease due to similar racial and environmental factors, as these factors can interact to influence serum IgG subclass levels. The present cross-sectional investigation attempted to examine the influence of serum IgG subclass levels and smoking status on periodontal condition in a population of elderly Japanese subjects.
  
  
  METHODS
  Elderly individuals (N = 451, age, 71 years) residing in Niigata City, Japan participated in the present study. Clinical evaluations, which consisted of probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and calculus, and serological determinations including serum IgG subclass levels and anti-Porphyromonas gingivalis fimbriae IgG subclass titers were conducted. All participants were asked to complete questionnaires regarding smoking status and were then divided into one of three groups: never smoker, former smoker, or current smoker.
  
  
  RESULTS
  Distributions of the number of teeth did not differ significantly across the groups. The proportion of sites with CAL > or =4 mm (%CAL4) in current smokers was significantly higher in comparison with never smokers. Multiple linear regression analysis revealed that %CAL4 was influenced by number of teeth, serum IgG2 levels, gender, and smoking status (R(2) = 0.253, P < 0.001). The effect of IgG2 was greater than that of smoking status. Distribution of IgG2 was not significantly different across the three groups.
  
  
  CONCLUSIONS
  These data indicate that serum IgG2 levels influences periodontal conditions in an elderly Japanese population independent of smoking status.
authors.affiliation: Department of Periodontology and Endodontology, School of Dentistry, Health Sciences University of Hokkaido, Japan. ben-chan@hoku-iryo-u.ac.jp
authors.forename: Keisuke
authors.initials: K
authors.lastname: Nakashima
authors.forename: Takao
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshihara
authors.forename: Jun
authors.initials: J
authors.lastname: Fujiwara
authors.forename: Hideo
authors.initials: H
authors.lastname: Miyazaki
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kowashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D036781:Fimbriae Proteins / Q000097:blood*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007564:Japan / Q000453:epidemiology; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D017622:Periodontal Attachment Loss / Q000209:etiology; D010510:Periodontal Diseases / Q000097:blood* / Q000453:epidemiology / Q000382:microbiology; D010512:Periodontal Index; D016966:Porphyromonas gingivalis / Q000276:immunology; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D036781:Fimbriae Proteins