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The Normal Glucose Tolerance Pattern: The Development of Blood Glucose Normality by an Analysis of Oral Signs Lingual Findings
Published in The Quarterly of The National Dental Association, estimated publication date April 1961.
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Introduction
There is still considerable debate as to what should be regarded as the normal glucose tolerance pattern. The presently accepted range has been developed by an analysis of presumably healthy individuals. A report has already been released1 in which the glucose tolerance pattern in a group of dental patients with and without oral symptoms has been analyzed. The symptoms which were studied were those (gingival tenderness, stomatopyrosis, and xerostomia) which are ordinarily recognized as being common findings associated with diabetes mellitus.
A second report2 has also been released in which the glucose tolerance pattern in a group of dental patients with and without extraoral symptoms has been analyzed. The symptoms which were studied (polyphagia, polyuria, and polydipsia) were those generally regarded as being common findings in the diabetic patient.
Three other reports have also been prepared designed to analyze the glucose tolerance pattern in a group of dental patients with and without gingival,3 dental,4 and oral roentgenographic5 signs generally regarded as common findings in patients with diabetes mellitus.
This report is designed to analyze the glucose tolerance pattern in a group of dental patients with and without lingual signs which are frequently regarded as being common findings associated with diabetes mellitus.
Review of the Literature
In order to appreciate the design and results of this study, it is necessary to review briefly: (1) the common lingual signs associated with diabetes mellitus, and (2) the present basis for the so-called normal glucose tolerance pattern.
Lingual Signs
The four most commonly reported lingual signs believed to be associated with diabetes mellitus are: (1) lingual color, (2) lingual size, (3) lingual fissures, and (4) lingual texture.
Lingual Color: Sheppard6 and Banks7 have simply pointed out the association between diabetes mellitus and lingual erythema. Sheridan et al,8 in a study of 100 routine dental patients, observed 19 percent of diabetic individuals with mild redness of the dorsum of the tongue in contrast to 5 percent of nondiabetic individuals with this same finding.
Lingual Size: Sheppard6 and Banks7 claimed macroglossia as a lingual finding in diabetic individuals. Sheridan and his group8 did not find any significant difference in the frequency with which macroglossia occurred in the diabetic and nondiabetic groups. Specifically, the latter study showed 23 percent of the diabetic patients with marginal indentation in contrast to 22 percent of the nondiabetic subjects with the same finding.
Lingual Fissures: Sheppard,6 Banks,7 Pollack, Person, and Knishkowy,9 and Martinez10 reported tongue fissuring as a sign of diabetes mellitus. Sheridan and his colleagues8 did not observe this finding as a significant delineator of the diabetic and nondiabetic groups.
Lingual Texture: Sheppard6 pointed out that denudation of the dorsal surface of the tongue may be associated with diabetes mellitus. In contrast, Sheridan et al8 could find no correlation between the diabetic state and smoothness of the dorsum of the tongue.
Normal Glucose Tolerance Pattern
There are two general approaches for establishing normal values:11 (1) statistical analysis, and (2) physiologic analysis.
Statistical Analysis: In general the values for the normal glucose tolerance pattern have been derived from an examination of presumably healthy individuals. In most cases, subjects have been regarded as well if relatively asymptomatic. Mosenthal and Barry12 have published a set of values which are now generally regarded as the normal glucose tolerance pattern. Their conclusions have been based upon the findings in 50 ambulatory hospital workers. These investigators suggest that the normal glucose tolerance test is represented by a fasting venous true glucose level of 100 or less mg. percent, no venous blood glucose level greater than 150 mg. percent, and a return of the blood glucose level to 100 or less mg. percent at the end of two hours. Figure 1 shows the specific mean values obtained by Mosenthal and Barry in their study.
Physiologic Analysis: There is no published report available which attempts to analyze the normal glucose tolerance pattern on the basis of the absence or presence of lingual signs which are commonly associated with diabetes mellitus.
Method of Investigation
One hundred dental patients were studied in the Section on Oral Medicine at the University of Alabama School of Dentistry. As far as possible, the subjects were selected at random. Table 1 shows the age distribution of the group. It can be observed that the pattern approaches a typical unimodal curve. Included in this study were 22 males and 78 females. Each subject was carefully examined regarding lingual color, size, fissures, and texture. If the dorsum of the tongue was pink, then zero was assigned. When the dorsum of the tongue was mild or bright red, then the values one and two were assigned respectively. This was the method used to describe tongue color. For tongue texture, a four-point system was used. Zero was assigned to describe normal tongue texture. Slight loss of the papillae at the tip of the tongue was indicated by the value one. Two was used to signify moderate papillary loss. Finally, generalized smoothness or denudation was given the score of three. Tongue size was recorded on a three-point scale with zero for normal size, one and two for slight and marked marginal indentations respectively. Tongue fissures were also graded on a three-point scale. Zero indicated no tongue fissures; one and two were used to signify slight and severe tongue fissuring respectively.
A true glucose tolerance test was performed on each patient according to the methods of Somogyi13,14 and Nelson.15 No preparatory diet was recommended except for complete fasting for 12 hours prior to the laboratory examination. Complete details regarding the method of investigation are available in the publication by Sheridan and his group.8
Results
The findings will be reported in two ways: (1) general characteristics, and (2) subgroup analyses.
General Characteristics
Figure 1 pictorially represents the suggested normal glucose tolerance pattern derived by Mosenthal and Barry from a study of 50 presumably healthy hospital workers. Figure 2 summarizes the data obtained from a study of 100 routine dental patients. Figure 3 is a composite graphic analysis of the findings in the 50 hospital workers in the Mosenthal and Barry series and the 100 dental patients in the Alabama study. The small mean differences at the fasting level, 30 and 60 minute points in the two groups are not statistically significant (P>.200) as outlined in Table 2. The only point at which there is a statistically significant difference of the mean is at two hours (P<.005).
Subgroup Analysis
The four signs studied will be analyzed as: (1) independent, and (2) combination groups.
Single Factors: Four signs were analyzed: (1) lingual size, (2) lingual color, (3) lingual texture, and (4) lingual fissures.
Lingual Size: The 100 patients in the Alabama series were divided into two groups: (1) those who demonstrated an increase in the size of the tongue and (2) those with normal size tongue (Figure 4). Eighty-one percent of the cases demonstrated normal tongue size; nineteen of the individuals showed macroglossia. Figure 4 shows the glucose tolerance patterns obtained from these two groups on the basis of the presence or absence of this one lingual sign. Several points are worthy of consideration. First, the mean differences at every temporal point are small. Secondly, on a mean basis, those individuals with normal tongue size showed slightly elevated glucose tolerance patterns, particularly at the one, two, and three hour points. Thirdly, it is clear from Table 2 that there is no statistically significant difference between these two groups.
Lingual Color: The 100 patients in the Alabama series were divided into two groups: (1) those who showed normal tongue color, and (2) those with abnormal lingual hue. Eighty-eight percent of the cases demonstrated normal tongue hue; twelve of the individuals showed abnormal color. Several points are worthy of consideration (Figure 5). First, the mean differences at every temporal point are small. Secondly, on a mean basis, those individuals with normal tongue color showed slightly elevated glucose tolerance patterns at the fasting, 30 and 60 minute points. Thirdly, it is clear from Table 2 that there is no statistically significant difference between these two groups.
Lingual Texture: The 100 patients in the Alabama series were divided into two groups: (1) those who demonstrated normal tongue texture, and (2) those with smoothness of the dorsum of the tongue (Figure 6). Eighty percent of the cases demonstrated normal tongue texture, twenty of the individuals showed smoothness of the tongue. Figure 6 shows the glucose tolerance patterns obtained from these two groups on the basis of the presence or absence of this one lingual sign. Several points are worthy of consideration. First, the mean differences at every temporal point are small. Secondly, on a mean basis, those individuals with normal tongue texture showed slightly elevated glucose tolerance patterns, particularly at the fasting, one hour, two hour, and three hour points. Thirdly, it is clear from Table 2 that there is a statistically significant difference between these two groups at the fasting level (P<.05).
Lingual Fissures: The 100 patients in the Alabama series were divided into two groups: (1) those who demonstrated no abnormal lingual fissures, and (2) those with abnormal tongue fissures. Ninety percent of the cases demonstrated normal tongue in this regard; ten of the individuals showed abnormal fissures. Figure 7 shows the glucose tolerance patterns obtained from these two groups on the basis of the presence or absence of this one lingual sign. Several points are worthy of consideration. First, the mean differences at every temporal point are small. Secondly, on a mean basis, those individuals with normal tongue fissures showed slightly elevated glucose tolerance patterns, particularly at the fasting, one hour, two hour, and three hour points. Thirdly, it is clear from Table 2 that there is no statistically significant [difference] between these two groups.
Combination Factors: Four independent lingual signs have already been considered. In this section, an analysis will be made of all of the combinations of these four signs. Actually, this includes nine different analyses. In order to conserve space, all of these relationships will not be shown graphically nor discussed. However, Table 2 indicates the statistical relationships. Only one of the relationships will be considered because it demonstrates statistically significant values.
Tongue Size and Texture: Sixty-six patients showed what appeared to be normal tongue size and texture while, in five subjects, there was evidence of macroglossia and smoothness of the tongue. Figure 8 shows the glucose tolerance patterns of these two groups. Two points deserve special consideration. First, the group with lingual signs, in the main, demonstrates a relative increase in glucose tolerance. Secondly, it is clear from Table 2 that there is only a statistical difference at the fasting level (P<.05).
Discussion
The data will be analyzed in three different ways: (1) a group analysis by comparison of the findings by Mosenthal and Barry with those observed in this study, (2) a subgroup analysis on the basis of the various lingual signs, and (3) a discussion of the age factor as it relates to blood glucose and lingual findings.
Group Analysis
It should be recalled that the present standards for the normal glucose tolerance curve include a fasting blood true glucose less than 100 mg. percent, no blood glucose level greater than 150 mg. percent, and a return to below 100 mg. percent in two hours. On the basis of these criteria, two possibilities can be entertained. If all of the above specifications must be met for normal or abnormal glucose tolerance, then the dental patients in this survey cannot be regarded as systemically healthy. This conclusion follows from the fact that significant differences between the Alabama and Mosenthal and Barry groups were observed at the two-hour period (Table 2 and Figure 3). If, on the other hand, normality and abnormality are to be judged on the basis of specific blood glucose criteria, then the dental patients must be regarded as either well or ill depending upon the specific yardstick employed. For example, on the basis of the fasting, 30 and 60 minute findings, the dental patients meet the specifications for normality. However, utilizing the two-hour determinations, the dental patients satisfy the requirements for systemic illness.
Subgroup Analysis
It is noteworthy that, with regard to single lingual findings, only the texture of the tongue proved significantly different at the fasting level (P<.05). It should be recalled that the difference between the fasting blood glucose levels of those with and without smoothness of the tongue was 6.9 mg. percent. Of particular interest is the observation (Figure 6) that the mean fasting blood glucose was higher for the group with normal tongue texture.
It is interesting in general to observe that, in contrast to oral symptoms,1 the findings with regard to lingual signs do not delineate the diabetic from the nondiabetic patient. The observations with combinations of two of the lingual signs are also enlightening. One observes only a statistically significant difference (P <.05) in the fasting glucose determinations in those patients with normaI tongue size and texture versus abnormal tongue size and texture. Once again, it is noteworthy that the mean fasting glucose of the normal group is higher than that observed for the group with macroglossia and abnormal tongue size.
Age Factor
There are some investigators who claim that blood glucose levels are normally higher in the older age groups. There is no disagreement that diabetes mellitus occurs more commonly in the autumnal years of life. Finally, there is controversial evidence that lingual signs of disease in general occur with greater frequency in the older age brackets. Therefore, it was thought advisable to restudy the data by keeping the age factor constant. Figure 9 shows the glucose tolerance patterns for those 50-59 year old patients with no evidence of lingual pathosis versus those in the same group with any sign of lingual disease such as an increase in tongue size, alteration in lingual hue, smoothness of the dorsum of the tongue and/or presence of fissures. It is clear from Figure 9 that, in the main, the mean glucose scores at every temporal point are higher for the normal group than observed for those with lingual signs of disease. A study of Table 3 shows that there is no statistical significance between the means at any one of the measuring points.
A similar study of the 60-69 year age group was done and the findings shown here for those in the 50-59 age bracket were found to b e essentially the same.
Summary
- On the basis of the overall glucose tolerance pattern, 100 routine dental patients appear normal if judged by the standards for glucose established by Mosenthal and Barry.
- On the basis of the mean two-hour determination in the true glucose tolerance pattern, 100 routine dental patients would be regarded as systemically abnormal.
- With regard to the analysis of single signs, smoothness of the tongue in contrast to macroglossia, abnormal tongue color and the presence of lingual fissures seems to be more related to diabetes mellitus (at least in the fasting determination).
- With respect to the study of the combinations of lingual signs, only the presence of macroglossia and smooth tongue appears to be related to the diabetic state (in the fasting determinations).
- In general, lingual signs are not as representative of the diabetic state as has been previously observed from a study of oral symptoms.1
- Within the limits of this study, the evidence suggests that the age factor does not play a role in the relationship of lingual signs to the glucose tolerance pattern.
- In an earlier report,16 it was shown that the relationship between oral symptoms and blood glucose tolerance follow a parabola. In other words, patients with hypo- and hyperglycemia demonstrate the very same symptoms. Therefore, a report to follow will consider the relationship of fasting blood true glucose to lingual signs.
References Cited:
- Cheraskin, E., Brunson, C., Sheridan, R. C., Jr., Flynn, F. H., Hutto, A. C., Keller, S. M., and Basile, J. “The normal glucose tolerance pattern: the development of blood glucose normality by an analysis of oral symptoms.” Periodont. 31: No.2, 123-137, April 1960.
- Cheraskin, E., Brunson, C., and Goodwin, J. D. “The normal glucose tolerance pattern: the development of blood glucose normality by an analysis of extraoral symptoms.” Periodont. 31: No.3, 197-206, July 1960.
- Cheraskin, E. and Keller, S. E. “The normal glucose tolerance pattern; the development of blood glucose normality by an analysis of oral signs (gingival findings).” Nat. Dent. Assn. 18: No. 4, 93-104, July 1960.
- Cheraskin, E. and Moller, P. “The normal glucose tolerance pattern: the development of blood glucose normality by an analysis of oral signs (dental findings).” West. Soc. Periodont, 8: No.3, 81-94, September 1960.
- Cheraskin, E. and Manson-Hing, L. “The normal glucose tolerance pattern: the development of blood. glucose normality by an analysis of oral roentgenographic findings.” Oral Surg., Oral Med. and Oral Path. 13: No.7, 819-835, July 1960.
- Sheppard, I. M. “Alveolar resorption in diabetes mellitus.” Cosmos 78: #10, 1075-1079, October 1956.
- Banks, S. O., Jr. “Diabetes and its oral manifestations: a medico-dental problem.” Nat. Dent. Assn. 4; No 1, 7-11, October 1945.
- Sheridan, R. C., Jr., Cheraskin, E., Flynn, F. H. and Hutto, A. C. “Epidemiology of diabetes mellitus: II. A study of 100 dental patients.” Periodont. 30: No. 4, 298-323, October 1959.
- Pollack, H., Person, P. and Knishkowy, E. “Diabetes mellitus, its relation to oral pathosis. II. Oral lesions seen in diabetes mellitus.” Periodont. 18: No.4, 155-158, October 1947.
- Martinez, E. “Diabetes in dental practice.” Abst, 1: No.3, 178, March 1956.
- Ivy, A. C. “What is normal or normality?” Bull. Northwestern Univ. Med. Sch. 18: No.1, 22-32, Spring Quarter 1944.
- Mosenthal, H. O. and Barry, E. “Criteria for and interpretation of normal glucose tolerance test.” Int. Med. 33: No. 5, 1175-1194, November 1950.
- Somogyi, M. “A new reagent for the determination of sugars.” Biol. Chem. 160: No.1, 61-68, September 1945.
- Somogyi, M. “Determination of blood sugars.” Biol. Chem. 160: No. 1, 69-73, September 1915.
- Nelson, N. “A photometric adaptation of the Somogyi method for the determination of blood sugar.” BioI. Chem. 153: No. 2, 375-380, May 1944.
- Cheraskin, E. and Brunson, C. “The relationship of fasting blood glucose to oral symptoms.” Appl. Nutrit. 13: No. 1, 2-19, May 1960.
- Morgan, B. H. and Cheraskin, E. “The relationship of fasting blood glucose to lingual signs.” (in preparation)