OBSERVATIONS ON THE ONE HOUR TWO DOSE
DEXTROSE TOLERANCE TEST*
J. SHIRLEY SWEENEY, J. J. MUIRHEAD AND LOUIE E. ALLDAY
Dallas, Texas
'
Recently Exton and Rose1 published results of what they
termed the "one-hour two-dose dextrose tolerance test", an
ingenious modification of the ordinary dextrose tolerance test
originally designed to obviate some of the misleading results
obtained by the more commonly used procedures. They mentioned various factors influencing the commonly employed dextrose tolerance test—the effects of antecedent diets or food habits
of the individual examined, the time the test was performed,
rate of absorption from the intestine of the ingested dextrose,
and so on. On the basis of the paradoxical law of dextrose,f
after varying the experimental conditions under which repeated
tolerance tests were made, these investigators conceived the idea
of giving two doses of glucose 30 minutes apart, on the assumption
that the first dose would activate the insulin glycogen mechanism.
The authors state that this test "gave no evidence of being in
any way affected by antecedent diets or irregularities of absorption, and very definitely indicated the practicability of adopting
the paradoxical law to routine clinical use." The value of the
Exton two-dose one-hour test has been thoroughly proved.
There is no question but that it eliminates many abnormal tolerance curves, more especially those showing an exceptionally high
* Received for publication March 31, 1937.
t'The paradoxical law of dextrose distinguishes sharply between diabetic
and every type of non-diabetic animals.... Limits of tolerance in non-diabetic
animals are all apparent, not real. The limits of tolerance in diabetic animals
are real, not apparent; just the opposite of the paradoxical law
Whereas
in normal individuals the more sugar given the more is utilized, the reverse is
true in diabetes" (F. M. Allen).
482
483
DEXTROSE TOLERANCE TEST
rise at the end of one hour, even though the blood sugar returns
to a normal level at the end of two hours. Such curves have
always been difficult to evaluate and it is just in these border
line cases that the two-dose one-hour test has its greatest value
and undoubtedly will become a more dependable means of differentiating suspected and renal diabetes from true diabetes. The
TABLE 1
RESULTS OF THE
O N E - H O U R T W O - D O S E T O L E B A N C B T E S T S ON F O U R
NORMAL
Y O U N G A D U L T S W H O H A D B E E N ON AN E X C L U S I V E P R O T E I N D I E T FOR
TWO
D A T S P R I O R TO T E S T S
SUBJECT
PASTING
3 0 MINUTES
6 0 MINUTES
A
B
C
D
65
70
64
70
155
160
133
127
170
190
148
143
9 0 MINUTES
165
200
138
143
1 2 0 MINUTES
142
182
121
108
TABLE 2
R E S U L T S O P THE O N E - H O U R T W O - D O S E T O L E R A N C E T E S T S ON S I X N O R M A L Y O U N G
A D U L T S W H O H A D B E E N ON AN E X C L U S I V E F A T D I E T T W O
DAYS
P R I O R TO T E S T S
SUBJECT
A
B
C
D*
E
F
PASTING
3 0 MINUTES
8 0 MINUTES
9 0 MINUTES
1 2 0 MINUTES
60
95
70
69
64
69
155
177
90
125
87
121
400
240
154
103
190
174
350
190
158
103
275
145
143
111
174
106
* This is a queer curve. In all probability absorptive factors were responsible
for its distortion.
test, also, has the advantage of requiring less time for its execution, and is certainly less disturbing to the patient.
The present study was made to determine the effects of extremely abnormal antecedent diets on the two-dose one-hour
test. We2 have shown previously that healthy, normal young
adults who had fasted for 48 hours, and who had been on exclusive
high fat diets as well as exclusive protein diets for a period of 48
hours preceding the ordinary dextrose tolerance test, yielded
AMERICAN JOURNAL O r CLINICAL PATHOLOGY, VOL. 7, N O . 6
484
S W E E N E Y , MTTIKHEAD AND ALLDAY
typical diabetic curves when given 1.75 grams glucose per kilogram of body weight. This was particularly true of those who
had fasted and had been on fats.
Normal, healthy, young adults were used in the present study.
Some of the students abstained from all food for forty-eight hours,
TABLE 3
R E S U L T S OP T H E O N E - H O U R T W O - D O S E T O L E R A N C E T E S T S ON F O U R
NORMAL
Y O U N G A D U L T S W H O H A D E A T E N N O F O O D F O R T W O D A Y S P R I O R TO T E S T S
SUBJECT
FASTING
3 0 MINUTES
6 0 MINUTES
9 0 MINUTES
1 2 0 MINUTES
A
B
C
D
69
52
67
67
105
114
111
108
157
181
156
190
177
221
184
210
182
217
TABLE 4
R E S U L T S OP T H E O N E - H O U R T W O - D O S E T O L E R A N C E T E S T S ON T W O N O R M A L Y O U N G
A D U L T S W H O H A D B E E N ON AN E X C L U S I V E CARBOHYDRATE D I E T FOR T W O
D A Y S P R I O R TO T E S T S
SUBJECT
FASTING
3 0 MINUTES
6 0 MINUTES
9 0 MINUTES
120 MINUTES
A
B
93
85
114
105
111
118
93
101
119
87
TABLE 5
C O M P O S I T E R E S U L T S OP T H E O N E - H O U R T W O - D O S E T O L E R A N C E T E S T ON N O R M A L
INDIVIDUALS W H O H A D B E E N ON E X C L U S I V E A N T E C E D E N T D I E T S AS INDICATED
IN T A B L E
FASTING
Proteins
Fats
Carbohydrates
Starvation
67
71
89
63
30
60
90
120
MINUTES
MINUTES
MINUTES
MINUTES
144
125
109
109
162
210
114
166
161
200
97
199
138
159
103
198
some ate only fats (egg yolks, cream and butter), some consumed
only protein (egg whites and meat), while others ate only sugars
for this period preceding the one-hour two-dose tolerance test.
The tolerance tests were performed according to the technic
DEXTROSE TOLERANCE TEST
485
outlined b y E x t o n and Rose. 1 All blood sugar determinations
were done b y t h e Folin-Wu technic.
I n tables 1 t o 4, are listed t h e results of t h e tests in these different groups. I n table 5, are t h e average figures for each group,
TABLE 6
RESULTS OF THE ONE-HOUR TWO-DOSE TOLERANCE TEST ON NORMAL INDIVIDUALS
WHO HAD BEEN ON A GENERAL DIET TWO DATS PRIOR TO TESTS
SUBJECT
FASTING
30 MINUTES
6 0 MINUTES
9 0 MINUTES
1 2 0 MINUTES
A
B
C
91
91
90
143
129
118
125
103
124
132
108
121
148
106
110
250
-
1
o
200
5
150
B
100
ft
o
r-l
A
P
30"
60"
90"
Time o f blood sugars
180"
CHABT 1. COMPOSITE GEAPH SHOWING ONE-HOUE TWO-POSE DEXTEOSE
TOLEEANCE CUEVE (EXTENDED TO TWO HOUES) OP FOUE NOEMAL YOUNG
ADULTS WHO HAD BEEN ON AN EXCLUSIVE PEOTEIN DIET FOE TWO DAYS
PEIOE TO TESTS
while in table 6 are t h e results for t h e controls (those who were
eating normally preceding t h e test). T h e results of these respective tests are presented graphically in charts 1 to 6.
Inspection of these figures and graphs reveals very definitely
and conclusively t h a t such extreme and abnormal antecedent
486
SWEENEY, MUIRHEAD AND ALLDAY
*
Q>
O
200
u
9
ft
«g> 150
| 100
1
50
30"
60 M
90"
Tine of blood sugars
P
CHART
2. COMPOSITE
GRAPH
SHOWING
ONE-HOUR
TWO-DOSE
120"
DEXTROSE
TOLERANCE CURVE (EXTENDED TO TWO HOURS) OP SIX NORMAL YOUNG
ADULTS W H O HAD B E E N ON AN EXCLUSIVE FAT D I E T FOR TWO DAYS PRIOR
TO TESTS
«
o
^200
150
100
o
50
30"
60"
90"
Time of blood, sugars
CHART
3. COMPOSITE
GRAPH
SHOWING
ONE-HOUR
TWO-DOSE
120"
DEXTROSE
TOLERANCE CURVE (EXTENDED TO TWO HOURS) OF FOUR NORMAL YOUNG
ADULTS W H O HAD EATEN N O FOOD FOR T W O DAYS PRIOR TO TESTS
487
DEXTROSE TOLERANCE TEST
13
8
u
&
250
200
ff 150
•
CHART
f
4. COMPOSITE
GRAPH
ggii
ggn
SC
Time of "blood sugars
SHOWING
ONE-HOUR
TWO-DOSE
I^QT.
DEXTROSE
TOLERANCE CURVE (EXTENDED TO TWO-HOURS) OP T W O NORMAL YOUNG
ADULTS W H O HAD B E E N ON AN EXCLUSIVE CARBOHYDRATE D I E T FOR T W O
DAYS PRIOR TO TESTS
f
CHART
5. COMPOSITE
go"
60"
90"
l i m e o f "blood, s u g a r s
GRAPHS SHOWING
ONE-HOUR
TWO-DOSE
ISO"
DEXTROSE
TOLERANCE CURVES (EXTENDED TO T W O HOURS) OP NORMAL INDIVIDUALS
W H O HAD B E E N ON DIFFERENT ANTECEDENT D I E T S AS INDICATED
(See table 5)
488
SWEENEY, MTJIRHEAD AND ALLDAY
dietary programs have a marked effect on the one-hour two-dose
glucose tolerance test. In other words, the resultant curves were
typically those of a diabetic, especially in the individuals who
had fasted and who had been on high fat diets. There is, however, one notable and interesting observation, and that is that
the one hour blood sugar levels in all groups were, in most instances, significantly lower, though abnormal (except in those
who had received only sugars preceding the test), than the one
I
«jj>150
fioo
150
F
30"
60"
90"
Time of "blood sugars
120"
CHART 6. COMPOSITE GRAPH SHOWING ONE-HOUR TWO-DOSE DEXTROSE
TOLERANCE CURVE (EXTENDED TO TWO HOURS) OF NORMAL YOUNG ADULTS
WHO HAD BEEN ON A GENERAL DIET TWO DAYS PRIOR TO TESTS
hour levels obtained following the ordinary single dose dextrose
tolerance test. 2
Furthermore, following the blood sugar changes beyond the
one hour limit, most of them are seen to drop more sharply at
the end of 2 hours. The composite, or average, curve of each
group in general is materially lower at the end of 2 hours than
those following the single dose tolerance test. It is only reasonable to assume that these variations are due to the two doses
of dextrose ingested at 30-minute intervals. The curves of the
individuals used as controls, in general, were strikingly comparable to those presented by Exton and Rose, 1 and others who
DEXTROSE TOLERANCE TEST
489
have substantiated their findings. The two-dose one-hour test
does show definite changes in individuals who have been on ordinary diets preceding the test. It is our opinion that it will
serve as a very valuable differential diagnostic test.
SUMMARY
The effect, of extreme and abnormal antecedent diets on the
one-hour two-dose tolerance test of Exton and Rose1 has been
studied.
It is shown that such abnormal antecedent dietary programs
distort the one-hour curves following 2 doses of dextrose in much
the same way they do the ordinary, or commonly used, single
dose tolerance test.
There is a slight tendency for the blood sugar levels not to
rise to quite such high figures, and to return to relatively less
abnormal values at the end of two hours.
REFERENCES
(1) EXTON, W. G., AND ROSE, A.: The One-Hour Two-Dose Tolerance Test.
Amer. Jour. Clin. Path. 4: 381-399. 1934.
(2) SWEENEY, J. SHIRLEY: Dietary Factors that Influence the Dextrose
Tolerance Test. Arch. Int. Med., 40: 818-830. 1927 (Dec).