Linköping University Medical Dissertations No. 1343
Periodontitis and coronary artery disease Studies on the association between periodontitis and coronary artery disease
Carin Starkhammar Johansson Division of Cardiovascular Medicine Department of Medical and Health Sciences
Linköping University, Sweden
Centre for Oral Rehabilitation Public Dental Health Care County Council of Östergötland, Sweden
Linköping 2013
© Carin Starkhammar Johansson, 2013 Cover picture/illustration: Greta Johansson Published article was reprinted with the permission of the copyright holder. Printed in Sweden by LiU‐Tryck, Linköping, Sweden, 2013. ISBN 987‐91‐7519‐748‐7 ISSN 0345‐0082
With love to Pelle, Greta and Olle ”Utan tvivel är man inte klok.” Tage Danielsson, 1928‐1985
Contents
CONTENTS ABSTRACT .................................................................................................................. 1 POPULÄRVETENSKAPLIG SAMMANFATTNING ......................................... 3 PREFACE ...................................................................................................................... 5 ABBREVIATIONS AND DEFINITIONS .............................................................. 6 INTRODUCTION....................................................................................................... 9 Historical perspective.......................................................................................... 9 Periodontitis........................................................................................................ 11 Complexity of oral microflora..................................................................... 12 Host response in periodontitis.................................................................... 14 Atherosclerosis ................................................................................................... 15 Normal histology of the arterial ................................................................. 15 Atherosclerosis, a consequence of inflammation and immune response ......................... 17 Wound healing process................................................................................ 19 Periodontitis‐CAD association........................................................................ 21 Possible explanatory factors for the periodontitis‐CAD association .... 32 Periodontal treatment effect on systemic inflammation......................... 35 Shared risk factors – confounders .............................................................. 36 Rationale for the studies .............................................................................. 40 OBJECTIVES ............................................................................................................. 41 HYPOTHESES ........................................................................................................... 42 MATERIAL ................................................................................................................ 43
Contents
METHODS ................................................................................................................. 45 RESULTS .................................................................................................................... 50 DISCUSSION ............................................................................................................ 58 CONCLUSIONS ....................................................................................................... 66 ACKNOWLEDGEMENTS ...................................................................................... 67 REFERENCES ............................................................................................................ 69
Abstract
ABSTRACT Periodontitis and coronary artery disease (CAD) are highly prevalent in Sweden’s population; both diseases have complicated pathogeneses and clinical manifestations due to immune‐system triggered inflammation. Research in recent years reported that inflammation is a significant active participant in many chronic diseases. The literature described a CAD‐ periodontitis association, but underlying mechanisms are not fully understood. It is important to acquire knowledge about how periodontitis might influence CAD, which is one of the major causes of illness and death in western countries. Because periodontitis can be treated, this knowledge, when complemented with more knowledge about the CAD‐periodontitis association, could lead to CAD prevention. The overall aim of studies reported in this thesis were to investigate the CAD‐periodontitis association, and specifically, to: (i) compare periodontal conditions in patients with CAD and subjects without a history of CAD; (ii) study whether or not periodontal status influences outcomes in known CAD over an 8‐year period; (iii) study whether or not concentrations and biological activity of hepatocyte growth factor (HGF) in serum from patients with severe CAD are different – depending on whether or not the subjects had periodontitis; and (iv) study concentrations and biological activity of hepatocyte growth factor in serum, saliva, and gingival crevicular fluid in healthy subjects with or without periodontitis. Here is a brief summary: In study I, 161 patients with CAD and 162 controls were compared regarding periodontal disease prevalence and severity. CAD patients had significant coronary stenosis and underwent percutaneous coronary intervention (PCI) or coronary artery by‐pass grafts (CABG). Healthy controls were recruited from Sweden’s population database. Twenty‐five per cent of the CAD patients had severe periodontitis, compared to 8% of the controls. In a multiple logistic regression analysis (controlled for age and smoking), severe periodontitis indicated an odds ratio of 5.74 (2.07–15.90) for CAD. Study II: Periodontal status was re‐examined in 126 CAD patients and 121 controls from the initial sample after 8 years. Periodontal status at baseline was analysed and related to CAD endpoints (i.e., myocardial infarction, new PCI or CABG or death due to CAD) recorded from patients’ medical records and from the death index maintained by the National Board of Health and Welfare. The difference in periodontitis prevalence and severity between the
1
Abstract
two groups remained unchanged during the 8‐year follow up. No significant differences were found regarding CAD endpoints during follow‐up in relation to baseline periodontal status in the CAD‐patient group. In study III, higher HGF serum concentrations (p