title: Coffee consumption and risk of fractures: a systematic review and dose-response meta-analysis.
abstract: OBJECTIVE
  The data on the association between coffee consumption and the risk of fractures are inconclusive. We performed a comprehensive literature review and meta-analysis to better quantify this association.
  
  
  METHODS
  We identified all potentially relevant articles by searching MEDLINE, EMBASE, Cochrane Library, Web of Science, SCOPUS, and CINAHL (until February 2013). The keywords "coffee," "caffeine," "drink," and "beverage" were used as the exposure factors, and the keyword "fracture" was used as the outcome factor. We determined the overall relative risk (RR) and confidence interval (CI) for the highest and lowest levels of coffee consumption. A dose-response analysis was performed to assess the risk of fractures based on the level of coffee consumption.
  
  
  RESULTS
  We included 253,514 participants with 12,939 fracture cases from 9 cohort and 6 case-control studies. The estimated RR of fractures at the highest level of coffee consumption was 1.14 (95% CI: 1.05-1.24; I(2)=0.0%) in women and 0.76 (95% CI: 0.62-0.94; I(2)=7.3%) in men. In the dose-response analysis, the pooled RRs of fractures in women who consumed 2 and 8 cups of coffee per day were 1.02 (95% CI: 1.01-1.04) and 1.54 (95% CI: 1.19-1.99), respectively.
  
  
  CONCLUSIONS
  Our meta-analysis suggests that daily consumption of coffee is associated with an increased risk of fractures in women and a contrasting decreased risk in men. However, future well-designed studies should be performed to confirm these findings.
authors.affiliation: Department of Family Medicine, Wonkwang University Sanbon Hospital, Wonkwang University School of Medicine, Gunpo, Republic of Korea. Electronic address: rednose7695@gmail.com.
authors.forename: Dong Ryul
authors.initials: DR
authors.lastname: Lee
authors.affiliation: Department of Family Medicine, Wonkwang University Sanbon Hospital, Wonkwang University School of Medicine, Gunpo, Republic of Korea. Electronic address: tracheo@naver.com.
authors.forename: Jungun
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Health Sciences, Centre of Biostatistics for Clinical Epidemiology, University of Milan-Bicocca, Monza, Italy; Dipartimento di Epidemiologia, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy. Electronic address: rota.matteo@libero.it.
authors.forename: Matteo
authors.initials: M
authors.lastname: Rota
authors.affiliation: Department of Biostatistics, Korea University College of Medicine, Seoul, Republic of Korea. Electronic address: jyleeuf@korea.ac.kr.
authors.forename: Juneyoung
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Republic of Korea. Electronic address: hsahn@korea.ac.kr.
authors.forename: Hyeong Sik
authors.initials: HS
authors.lastname: Ahn
authors.affiliation: Department of Family Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Republic of Korea; Department of Biomedical Sciences, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Republic of Korea. Electronic address: smpark.snuh@gmail.com.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Park
authors.affiliation: Jangseong Public Health Center, Jangseong, Republic of Korea. Electronic address: doosup87@gmail.com.
authors.forename: Doosup
authors.initials: D
authors.lastname: Shin
mesh_terms: D003069:Coffee / Q000009:adverse effects*; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology*; D006801:Humans; D008297:Male; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D003069:Coffee
keywords: Caffeine; Coffee; Dose–response relationship; Fracture; Meta-analysis