SCREENING FOR DIABETIC PATIENTSIN A SPECIALIST PERIODONTAL PRACTICE An analysis of 292 new patients referred to a specialist periodontal practice

who were screened for pre-diabetes or diabetes using a capillary blood glucose meter

Keith M. Gale BDS, FDSRCS (Eng), MDSc (Qld). (School of Dentistry, University of Western Australia and Private Practice)

Graph 4. Spread of blood glucose readings (mmol/l) in high risk patients

1. There was a marginally higher frequency of previously diagnosed diabetics (4.8%) in the overall population studied compared to the The Australian Diabetes, Obesity and Lifestyle Study (3.4%).

2. Approximately 50% of periodontal patients fulfilled the high risk criteria for type 2 diabetes.3. Only 65% of high risk patients agreed to provide a capillary blood sample.4. Nearly half of those patients tested returned random blood glucose levels of 5.7mmol/l.5. Reporting back by general medical practitioners was minimal and all but one required follow-up

telephone calls. One medical practitioner indicated he was too busy to attend to his patient!6. Of the 13 patients who recorded >7.0mmol/l, 2 were definitely diagnosed as diabetics and 3 were

possible pre-diabetics (IGT or IFG).

7. Despite reported concerns regarding the sensitivity and specificity of random capillary blood glucose screening the high risk screening used in this study will have altered the medical management of at least 5 periodontal patients (or 5% of those screened). In future the cut-off for referral to medical practitioners for OGTT will be raised to 7.0mmol/l but this will not preclude a re-screening of high risk patients every 3 years. The estimated cost per patient is about AU$2.50.

   References1. Dunstan DW, Zimmet PZ, Welborn TA, de Courten MP, Cameron AJ, Sicree RA, Dwyer T, Colagiuri S, Jolley D, Knuiman M, Atkins R, Shaw JE on behalf of the AusDiab Steering

Committee. The rising prevalence of diabetes and impaired glucose tolerance. The Australian Diabetes, Obesity and Lifestyle Study. Diabetes Care 2002;25:829-834

2. McCarty DJ, Zimmet P, Dalton A, Segal L, Welborn TA. The rise & rise of diabetes inAustralia,1996. A review of statistics, trends and costs. Diabetes Australia National Action Plan;Canberra:1996

3. Colagiuri S, Colagiuri R, Ward J. National diabetes strategy and implementation plan. Diabetes Australia;Canberra:1998

4. Loe, H. Periodontal Disease, The sixth complication of diabetes mellitus. Diabetes Care 1993;6 Supplement 1, 329-334.

5. Soskolne W, Klinger A The Relationship Between Periodontal Diseases and Diabetes: An overview, Annals of Periodontology. 2001;6:91-99.

6. Tsai C, Hayes C, Taylor GW. Glycemic control of type 2 diabetes and severe periodontal disease in the US adult population. Community Dent Oral Epidemiol. 2002;Jun;30(3):182-92.

7. Colagiuri S, Zimmet P, Hepburn A, Colagiuri R. Evidence Based Guidelines for Type 2 Diabetes: Primary Prevention, Case Detection and Diagnosis. Canberra, Australia, Diabetes Australia and National Health and Medical Research Council, 2002 (available at www.nhmrc.gov.au, reference No CP86)

8. The DECODE Study Group. Glucose tolerance and mortality: comparison of WHO and American Diabetes Association diagnostic criteria. Lancet. 1999;354:617-621.

9. Qiao Q, Keinanen-Kiukaanniemi S, Rajala U, Uusimaki A, Kivela SL. Random capillary whole blood glucose test as a screening test for diabetes mellitus in an middle aged population. Scand J Clin Lab Invest. 1995 Feb;55(1):3-8.

10. Engelgau MM, Thompson TJ, Smith PJ, Herman WH, Aubert RE, Gunter EW, Wetterhall SF, Sous ES, Ali MA. Screening for diabetes mellitus in adults. The utility of random capillary blood glucose measurements. Diabetes Care. 1995 Apr;18(4):463-6.

Thirteen patients (11%) had readings between 7.4 and 18.9mmol/l. Table 1. summarises the subsequent medical management of these patients, patients 1 and 3 were diabetic and there is a likelihood that patient 2 will prove to be pre-diabetic or diabetic when eventually laboratory tested. All were over 50 years old.

   DiscussionThe percentage of previously diagnosed diabetics was 4.8%, this is higher than the 3.4% reported in The Australian Diabetes, Obesity and Lifestyle Study by Dunstan et al. (2002)1. This would suggest that patients with diagnosed periodontal disease might indeed have a higher diabetic morbidity than healthy individuals (Loe, 1993)4. Only 2 patients who agreed to be tested recorded greater than 11.1mmol/l with the RCBG, one was subsequently prescribed oral antidiabetic medication and the other has currently failed to follow-up with his medical practitioner. In following up patient’s OGTT results there was the impression that some medical practitioners may not be too concerned with blood sugar levels greater than 5.6mmol/l and are more focused on levels over 11.1mmol/l (see patient 6 in Table 1.). There is evidence that patients with IGT (BGL fasting <7.0; 2-hour post glucose 7.8-11.00mmol/l) have a significant predictive risk of death from developing cardiovascular disease8 so several of those patients referred to in Table 1. may be undiagnosed cases of IGT or IFG. Two possible patients are currently under monitoring care due to the medical practitioner concerns (Patients 7 and 13).

Unfortunately the specificity and sensitivity of glucose meters has been considered too insensitive for routine screening (Qiao et al., 1995)9. These authors used a cut-off level for RCBG of 6.2mmol/l on 55 year olds and achieved a specificity of 92%% respectively for men and women but only sensitivity of 63% and consequently recommended use in populations with a high proportion (ie high risk) of potential diabetics. This study selected medically high risk patients and those with periodontitis which anticipated a higher proportion of diabetics. Qiao et al7 used a reflective meter whist this current study utilized an electrochemical meter. Nevertheless additional studies (eg Engelau et al., 1995)10 found better specificity and sensitivity if the cut-off was increased with age (6.3mmol/l for 30 year olds and 7.7mmol/l for those 75 years old).

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Graph 3. Distribution of blood glucose concentration and high risk factors

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Table 1. Medical management of 13 patients with highest RCBG recordings

No. Patient Age RCBG (mmol/l)

Max. periodontal pocket

General Medical Practitioner (GMP) follow-up

1 2662 60 yrs 18.9 9 mm GMP prescribed on oral medication 2 2752 66 yrs 14.2 6 mm GMP failed to follow-up 3 2502 60 yrs 10.2 10+ mm Previously diagnosed diabetic 4 2768 54 yrs 9.8 7 mm OGTT within normal range 5 2513 59 yrs 9.6 8 mm GMP recorded 5.1mmol/l 6 2640 58 yrs 9.0 7 mm GMP recorded 6.7 mmol/l – considered normal 7 2638 80 yrs 8.4 10+ mm GMP concerned and monitoring 8 2757 54 yrs 8.2 6 mm GMP failed to follow-up 9 2749 57 yrs 7.7 6 mm GMP recorded 5.6mmol/l 10 2482 60 yrs 7.6 10+ mm Patient cancelled all appointments 11 2717 60 yrs 7.6 8 mm GMP recorded “normal” 12 2491 71 yrs 7.5 5 mm GMP recorded “normal” 13 2764 51 yrs 7.4 7 mm GMP recorded 5.8mmol/l – will monitor

Age 55+

Age 45+

BP

Weight

Family

Heart

Gestational

IGT

POS Ethnic 2

Ethnic 1

Email contact: kmgale@cyllene.uwa.edu.au

   Introduction   About 7% of Australians aged 25 years and over have diabetes but only half of these have been diagnosed. The prevalence of diabetes rises from 2.4% in people between the ages 35 to 44 years to 23.0% in those 75 years and over. Another 16.4% may be pre-diabetic with either impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) suggesting almost 1 in 4 Australians have an altered blood sugar metabolism (Dunstan et al, 2002)1. Diabetes has a high health and cost problem as a result of its long term complications which include large vessel disease (such as heart disease, stroke, and erectile dysfunction); foot ulceration, gangrene and lower limb amputation; renal failure and visual impairment (including blindness) (McCarty et al, 1996; Colagiuri et al, 1998)2,3.

In 1993 Harald Löe4 described the signs and symptoms of periodontitis as the “sixth complication” of diabetes due to the increased prevalence of periodontal disease in diabetics. This increase may be almost double (17%) compared to non- diabetics (9%) (Soskolne and Klinger, 2001; Tsai et al., 2002) 5,6. Given the typically long, asymptomatic, pre-clinical phase associated with type 2 diabetes, early detection is both warranted and feasible. Screening high risk patients is a method of identifying early development of increased blood sugar levels and there may be an even greater likelihood of this occurring in the older periodontally diseased adult.

   AimThis study was designed to see if the random capillary blood glucose (RCBG) screening of new patients in a specialist periodontal practice would enhance in the early detection of pre-diabetes or diabetic states.

   MethodAll new patients referred to a specialist periodontal practice for treatment filled in a questionnaire to identify those who were at high risk for type 2 diabetes7:

• >55 years old • >45 years with high blood pressure; • >45 years, overweight and/or elevated blood fats; • >45 years and an immediate family member with diabetes; • has/had heart disease or a heart attack; • has/had high blood sugar during pregnancy (gestational diabetes); • has/had borderline blood glucose levels (eg impaired glucose tolerance - IGT); • has polycystic ovary syndrome (POS) and overweight; • >35 years old and Aboriginal, a Torres Strait Islander (Ethnic 1), from the Pacific Islands, Indian subcontinent or of Chinese origin (Ethnic 2).

With a patient’s written consent and under aseptic conditions a random (ie non-fasting) sample of capillary blood was obtained from the finger using a disposable lancet and the glucose level (RCBG) recorded using an AccuChek Advantage glucose meter. Performance checks and calibration were carried out prior to the use of each new batch of test strips.

Additional data recorded for each patient included medical history, age, sex, time of last oral intake, deepest periodontal pocket from a whole mouth charting. Patients with readings over 5.6mmol/l were referred to their general medical practitioner with a specific request for follow-up laboratory oral glucose tolerance testing (OGTT).

   ResultsA total number of 292 new patients (age range 15 – 80 years, mean 50 years) were examined over the period of the study. The number of patients who gave a positive medical history for diabetes was 14 (4.8%) (4 were type 1 and 10 were type 2 diabetics) (Graph 1.).

One hundred and sixty five patients (56.6% - 104 females, 61 males) admitted to falling into one or more of the high risk groups (Graph 2.).

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Graph 1. Frequency of diagnosed diabetics Graph 2. Frequency distribution of gender and high risk factors

The most common high risk category in the sample of patients screened was being >55 years old, followed by >45 years old and overweight or with a family history of diabetes and, less frequently, with hypertension.

From these high risk patients 105 (64.9% - 66 females, 39 males) agreed to provide a blood sample to test for capillary blood glucose. Nearly half (50) gave a reading ≥5.7mmol/l (Graphs 3. and 4.).

Acknowledgments: Special thanks go to Tracey Murfett, Cathy Gale and Natascha Stone for their help in collecting the data for this study. Thanks also go to Prof. Tim Welborn for his initial help in setting up the analysis, to Dr. Mary Cullinan again for her encouragement and to Dennis Barnden for his assistance with the layout of this presentation.

Age 55+

Age 45+

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Family

Heart

Gestational

IGT

POS Ethnic 2

Ethnic 1

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Non-diabetic

Type 2 diabetes

Type 1 diabetes

   Conclusions

Figure 1. Method of sampling capillary blood glucose levels