title: Is weight gain associated with the incidence of periodontitis? A systematic review and meta-analysis.
abstract: OBJECTIVE
  This study aimed to conduct a systematic review assessing the effects of weight gain on the incidence of periodontitis in adults.
  
  
  METHODS
  Electronic searches in four databases were performed up to and including February 2015. Only prospective longitudinal studies assessing the association between weight gain and the incidence of periodontitis in adults were eligible to be included in this study. All studies should state a clear description of nutritional status (Body Mass Index; Waist Circumference) as well as the case definition of periodontitis. Pooled relative risks (RR) for becoming overweight and obese on the incidence of periodontitis were estimated by meta-analysis. Quality was assessed with the Newcastle-Ottawa scale for cohort studies.
  
  
  RESULTS
  Five articles were included in this review and meta-analysis with 42,198 subjects enrolled. Subjects who became overweight and obese presented higher risk to develop new cases of periodontitis (RR 1.13; 95%CI 1.06-1.20 and RR 1.33 95%CI 1.21-1.47 respectively) compared with counterparts who stayed in normal weight.
  
  
  CONCLUSIONS
  A clear positive association between weight gain and new cases of periodontitis was found. However, these results are originated from limited evidence. Thus, more studies with longitudinal prospective design are needed.
authors.affiliation: Postgraduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.|Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: Gustavo G
authors.initials: GG
authors.lastname: Nascimento
authors.affiliation: Postgraduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.|Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: Fábio R M
authors.initials: FR
authors.lastname: Leite
authors.affiliation: Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: Loc G
authors.initials: LG
authors.lastname: Do
authors.affiliation: Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: Karen G
authors.initials: KG
authors.lastname: Peres
authors.affiliation: Postgraduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Marcos B
authors.initials: MB
authors.lastname: Correa
authors.affiliation: Postgraduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.|Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Flávio F
authors.initials: FF
authors.lastname: Demarco
authors.affiliation: Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: Marco A
authors.initials: MA
authors.lastname: Peres
mesh_terms: D015992:Body Mass Index; D006801:Humans; D009752:Nutritional Status; D009765:Obesity / Q000150:complications; D050177:Overweight / Q000150:complications; D010518:Periodontitis / Q000209:etiology*; D055105:Waist Circumference; D015430:Weight Gain / Q000502:physiology*
keywords: incidence; longitudinal studies; meta-analysis; nutritional status; obesity; overweight; periodontal disease; periodontitis; systematic review; weight gain