Earlier this year, delegates of the European Federation of Periodontology (EFP) and the International Diabetes Federation (IDF) had met in Madrid for a joint workshop on an update of the Perio-Diabetes link. I had reported on the event and some key findings, quickly posted on the EFP web page, here.
Already on and after 24 August 2017, a Consensus Report by the two organizations was prematurely published, and quickly (temporarily) withdrawn, in the EFP’s Journal of Clinical Periodontology and the IDF’s Diabetes Research and Clinical Practice. I had managed to get a print-out of the not-yet edited (and later withdrawn) draft version published on the JCP Accepted Articles page and had noticed that most of the evidence presented was derived of yet-to-be published review articles based on the workshop proceedings.
The final version of the Consensus Report (Sanz et al. 2017, Early View Articles), including guidelines for patients and health professionals dealing with patients suffering from diabetes and periodontal disease, went online this week, but still references to review papers presented on the occasion of the workshop have a 2017 assignment and are not paginated which may make it more difficult for scientists and clinicians outside periodontology or dentistry to locate the final papers.
To be clear, when it comes to keeping our medical collegues, and in particular diabetologists, interested in the very long-known link between periodontitis and metabolic diseases, proving beneficial effects of periodontal treatment on diabetic control is crucial. All was fine as long as numerous published, small-scale, mostly single-center, and often poorly executed, trials apparently showed that thorough subgingival scaling in patients with both periodontitis and diabetes led to an about 0.4% reduction of glycated hemoglobin (HbA1c), at least after three or four months. As that would in effect spare an additional antidiabetic drug, diabetologists stayed interested. Although results in a few trials indicated that the effect was not long-lasting, i.e., no longer discernable after, say, six months.
Last weekend, EFP and International Diabetes Federation (IDF) delegates, in partnership with Sunstar, had met in Madrid and had worked on guidelines for dentists, medical doctors and patients with periodontitis and/or diabetes. The EFP website features some key findings when reviewing the literature. In particular, it is claimed that,
evidence suggests that periodontitis patients have a higher chance of developing pre-diabetes and type-2 diabetes and that people with periodontitis and diabetes have more difficulty in keeping their blood-sugar levels under control. Furthermore, patients with both diseases are more likely to develop diabetic complications than people with diabetes without periodontitis.
Current evidence indicates that in people with diabetes, periodontal therapy accompanied by effective self-performed oral hygiene at home is both safe and effective – even in people with poorly controlled diabetes. Similarly, there is consistent evidence that periodontal therapy reduces blood-sugar levels in people with diabetes and periodontitis. (Emphasis added.)
Claims and denials of clinically relevant effects of, in particular, non-surgical periodontal treatment on markers of diabetic control have not only led to a surge of new randomized clinical trials and systematic reviews thereof. If anybody had hope that the current frenzy has found a happy end with the updated and very comprehensive Cochrane review by Simpson et al. (2015) (s)he has been mistaken. In the June issue of the Australian Dental Journal, Botero et al. (2016) report on an umbrella review in which they systematically reviewed all systematic reviews on the subject, be it with or without meta-analysis, published between 1995 and 2015. The paper has been accepted for publication on January 20, 2016. It has to be emphasized that using the term “umbrella review” is somewhat misleading. In a strict sense, an umbrella review assembles together several systematic reviews on the same condition in the presence of many treatments or many important outcomes.
In a previous post, I have expressed considerable concern about an assumed advertorial in our leading periodontal journal, JCP. Quintessence Publishing was about to launch their fourth installment of “3D” animated, short (each 15-17 min) movies all called Cell-to-Cell Communication, “Oral Health and General Health – The Links between Periodontitis, Atherosclerosis, and Diabetes.” Previous movies have been offered for purchase by QuintPub for a remarkable amount of around $100. Luckily, the new one can now be found on the EFP homepage and accessed by members and non-members for free.
The recent largely expanded Cochrane Systematic Review on periodontal treatment for glycemic control in diabetics by Simpson et al. 2015 calculates, in one of numerous meta-analyses, a weighted mean 0.29% reduction (95% confidence interval 0.10% lower to 0.48% lower) of HbA1c 3-4 months after nonsurgical periodontal therapy. Fourteen clinical trials were considered comprising about 1499 patients with both diabetes and periodontitis. The quality of evidence was considered low. Quality was downgraded twice, first for risk of bias, mainly due to lack of blinding; and then due to moderate heterogeneity (I2 = 0.53%). The observed small reduction of 0.29% was not sustained afterwards . At 6-month follow-up (the meta-analysis considered 5 studies with 826 patients), the weighted mean reduction was 0.02% (95% CI 0.20% lower to 0.16% higher).