Table 1.
Characteristics of included studies
| Year/study | Design | Location | No. COPD/control subjects | Age (COPD/ control subjects) |
Assessment of PD | Assessment of COPD |
| Hayes et al 28 1998 | Case–control | USA | 261/857 | 45.1±9.7/42.2±9.1 | ABL | FEV1 |
| Scannapieco et al 14 1998 | Cross-sectional | USA | 77/309 | NA | OHI | Self-reported |
| Garcia et al 29 2001 | Case–control | USA | 279/833 | NA | ABL, PPD | FEV1 |
| Scannapieco et al 30 2001 | Cross-sectional | USA | 810/12 982 | 51.2±17.9/43.9±17.7 | CAL, GB | Self-reported |
| Hyman et al 20 2004 | Cross-sectional | USA | 993/6 632 | 62.3±14.1/47.4±14.2 | CAL | GOLD |
| Leuckfeld et al 31 2008 | Cross-sectional | Norway | 130/50 | 54.9±4.9/47.0±9.8 | ABL | GOLD |
| Wang et al 19 2009 | Case–control | China | 306/328 | 63.9±9.8/63.3±9.0 | CAL, PLI | GOLD |
| Liu et al 42 2012 | Case–control | China | 183/209* | 64.3±10.1/63.6±9.7 | CAL, PPD, BI | GOLD |
| Si et al 15 2012 | Case–control | China | 581/438 | 63.9±9.4/62.8±9.5 | CAL, ABL, PPD, PLI, BI | GOLD |
| Zhou et al 32 2012 | Case–control | China | 193/181 | 63.6±10.3/62.1±9.1 | CAL, ABL, PPD, PLI, BI | GOLD |
| Barros et al 21 2013 | Cohort | USA | 399/1236† | 63.9±5.7/66.0±5.1 | CAL, PPD | GOLD |
| Ledić et al 33 2013 | Case–control | Croatia | 93/43 | 65.8±9.7/62.1±11.9 | CAL | GOLD |
| Chung et al 34 2016 | Cross-sectional | Korea | 697/5181 | 64.3±0.2/54.6±0.1 | PPD, GB | GOLD |
| AbdelHalim et al 43 2018 | Cross-sectional | Egypt | 134/116* | 56.8±10.4/55.3±9.1 | CAL, PPD, BI, PLI, OHI | GOLD |
| Harland et al 35 2018 | Cross-sectional | Japan | 149/1325 | 61.3±9.1/54.5±8.7 | PPD | GOLD |
| Lopez-de-Andrés et al 36 2018 | Case–control | Spain | 2699/2699 | 63±14/61±14 | Self-reported | Self-reported |
| Takeuchi et al 37 2019 | Cohort | Japan | 22/878 | NA | CAL, PPD | GOLD |
| Jung et al 38 2020 | Cross-sectional | Korea | 1134/6585 | 62.6±0.4/53.6±0.2 | PPD | FEV1/FVC |
| Qian et al 16 2020 | Cohort | China | 23‡/NA | 83.1±4.8/80.3±3.7 | ABL | NR |
| Winning et al 39 2020 | Cross-sectional | Sweden | 86/740 | NA | ABL | GOLD |
| Zhou et al 40 2020 | Case–control | China | 60/60 | 63.1±10.1/60.0±9.4 | CAL, PLI | GOLD |
| Kataoka et al 41 2021 | Cross-sectional | Japan | 464/249 | 54.1±9.4/NA | PPD | GOLD |
Continuous data are presented as mean±SD unless otherwise indicated.
*No. COPD subjects with frequent exacerbation (≥2 exacerbations in the last year)/infrequent exacerbation (<2 exacerbations in the last year).
†No. COPD subjects with events (hospitalisation for exacerbation or COPD-related death) in the 5-year follow-up visit/COPD subjects without events in the 5-year follow-up visit.
‡No. COPD-related mortality in a follow-up visit more than 5 years.
ABL, alveolar bone loss; BI, bleeding index; CAL, clinical attachment level; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; GB, gingival bleeding; GOLD, Global Initiative for Chronic Obstructive Lung Disease; OHI, oral health index; PD, periodontal disease; PLI, plaque index; PPD, probing pocket depth.