People with undetected glucose disorders run a higher risk of both myocardial infarction and periodontitis, according to a study published in the journal Diabetes Care by researchers at Karolinska Institutet in Sweden.
The results demonstrate the need of greater collaboration between dentistry and healthcare, say the researchers, and possibly of screening for diabetes at dental clinics.
Severe periodontitis is already known to be associated with a higher risk of myocardial infarction and lowered glucose tolerance, and diabetes to be more common in people who have suffered a heart attack.
The researchers behind these earlier findings have now studied whether undetected glucose disorders (dysglycaemia) – that is, a reduced ability to metabolise sugar – is linked to both these conditions: myocardial infarction and periodontitis.
The results are published in the journal Diabetes Care.
The study was a collaboration between cardiologists and dentists at Karolinska Institutet and was based on data from a previous study called PAROKRANK.
It included 805 myocardial infarction patients from 17 Swedish cardiology clinics and 805 controls, who were matched by age, sex and post code.
The patients’ periodontitic status was assessed with X-rays and dysglycaemic status with glucose load tests.
Participants with a diabetes diagnosis were excluded from the study, which left 712 patients and 731 controls with data on both periodontitic status and glucose status, the latter of which was divided into three categories: normal, reduced glucose tolerance, newly detected diabetes.
Comparisons were made after adjusting for age, sex, smoking habits, education and civil status.
The study shows that previously undetected glucose disorders, which include diabetes and impaired glucose tolerance, were linked to myocardial infarction.
It was roughly twice as common for myocardial infarction patients to have undetected dysglycaemia as for healthy controls, confirming the research group’s earlier findings. Myocardial infarction affects approximately 30,000 people in Sweden annually.
Dysglycaemia, defined as type 2 diabetes (T2DM) or impaired glucose tolerance (IGT), is an important risk factor for cardiovascular disease (CVD), the commonest cause of death globally .
Screening for dysglycaemia is performed by means of three blood tests: glycated haemoglobin A1c (HbA1c), fasting plasma glucose (FPG) and a 2 hour post load plasma glucose (2hPG), the latter only obtainable by means of an oral glucose tolerance test (OGTT) .
Several scoring systems for estimating the future risk of T2DM have been developed.
One of them, the FINDRISC questionnaire, has been validated in several European populations.
FINDRISC classifies the respondent as having a low, moderate, high or very high risk of developing T2DM during the forthcoming decade.
If an individual is at a high or very high risk, an OGTT is recommended for further investigation .
Importantly, not only T2DM but also its preceding, hyperglycaemic state IGT increases the risk of CVD [4, 5].
Other intermediate hyperglycaemic states include impaired fasting glucose (IFG) and “high-risk” glycated haemoglobin A1c (HbA1c).
The Atherosclerosis Risk in Communities (ARIC) study reported that people with “high risk” HbA1c are at increased risk of developing diabetes and CVD independent of FPG , but a postload glucose was not included in this study. Other population based studies among them the Diabetes Epidemiology: Collaborative Analysis of Diagnostic Criteria in Europe (DECODE), a substudy of the DECODE population and the Framingham Offspring Study demonstrated that the 2hPG is a significantly stronger predictor of future CVD and all-cause mortality than FPG and HbA1c [7–9].
Similar findings were recently presented from a large European population of patients with coronary artery disease .
Screening for dysglycaemia is encouraged by the fact that T2DM can be prevented or delayed by approximately 50% with lifestyle and/or pharmacological interventions [11–13].
Although advocated by contemporary guidelines systematic screening of high risk people is infrequently implemented .
A concern is therefore that large proportions of dysglycaemic individuals remain unrecognized, thereby deprived preventive opportunities.
This study tested the hypotheses that (1) if appropriately screened the prevalence of dysglycaemia is high in patients free from CVD but treated for hypertension and/or dyslipidaemia, and (2) that initiating screening with the FINDRISC questionnaire would limit the need for more expensive and time consuming blood tests.
These hypotheses were tested within the auspices of the European Action on Secondary Prevention through Intervention to Reduce Events-IV (EUROASPIRE-IV), a large cross-sectional survey.
Undetected diabetes was also found to be linked to severe periodontitis.
When myocardial infarction patients and controls were analysed separately, the association was clearer in the patients than in the controls, which is possibly because many of the controls were very healthy and few had severe periodontitis and undetected diabetes.
“Our findings indicate that dysglycaemia is a key risk factor in both severe periodontitis and myocardial infarction and that the combination of severe periodontitis and undetected diabetes further increases the risk of myocardial infarction,” says the study’s lead author Anna Norhammar, cardiologist and Associate Professor at Karolinska Institutet’s Department of Medicine in Solna.
The results substantiate previously known links between periodontitis and diabetes and show that such an association also exists in previously unknown diabetes.
According to the researchers, the findings should make diabetes specialists consider their patients’ dental health and the need for closer collaboration with dentists.
“The PAROKRANK study is a good example of such collaboration,” says the present study’s senior author Lars Rydén, Professor at Karolinska Institutet’s Department of Medicine in Solna and chair of the academically initiated PAROKRANK study.
“Our study shows that undetected glucose disorders are common in two major diseases—myocardial infarction and periodontitis,” says Dr. Norhammar.
“Many people visit the dentist regularly and maybe it’s worth considering taking routine blood-sugar tests in patients with severe periodontitis to catch these patients.”
One of the study’s limitations is that despite the large number of participants, the number of patients and controls with severe periodontitis and undetected diabetes was low.
The observed differences in the links between undetected diabetes and severe periodontitis in patients and controls can therefore be attributable either to the low number of patients or to genuine differences in correlation.
More information: Anna Norhammar et al. “Undetected dysglycaemia an important risk factor for two common diseases: myocardial infarction and periodontitis – A report from the PAROKRANK study.” Diabetes Care, online 10 June 2019. doi.org/10.2337/dc19-0018. care.diabetesjournals.org/cont … 2019/05/10/dc19-0018
Journal information: Diabetes Care
Provided by Karolinska Institutet