Download Blood Glucose Monitoring Performance of “Roche Accu

Turkish Journal of Endocrinology and Metabolism, (2005) 4 : 115-118
ORIGINAL ARTICLE
Blood Glucose Monitoring Performance of
“Roche Accu-Check Go” Glucometer Device at
Moderately High Altitude
Habib Bilen*
Alpaslan Kılıçaslan**
Güngör Akçay*
İlyas Çapoğlu*
* University of Atatürk,School of Medicine, Department of Internal Medicine, Division of Endocrinology, Erzurum, Turkey
** University of Hacettepe, School of Medicine, Department of Internal Medicine, Ankara, Turkey
To evaluate the performance of Roche Accu-check glucometer device compared to
reference laboratory measurement in moderately high altitude. Research Design and
Methods: Fasting blood glucose measurements were made simultaneously by Accucheck go glucometer device and standard laboratory methods in a group of 204 male
and female patients residing in Erzurum, a province in Eastern Turkey with an
altitude of 2000 meters. Majority of patients had type 2 diabetes. Results: Average
fasting blood glucose levels measured with Accu-check go (101.5; 71-456) were lower
compared to reference values (102.5; 69-456), with no statistically significant
difference. Also, there were no significant differences between the two methods with
regard to measured values below and above the threshold level of 126. The type of
diabetes and gender had no effect on measurements. Conclusions: Slightly lower
glucose levels observed with Accu-check go at a moderately high altitude of 2000
meters can be explained on the basis of oxidoreductase method used. However,
absence of any significant difference suggests that the ability of Accu-check go to
detect hypoglycemia at this altitude at an early stage is not compromised.
Keywords: Accu-check go, altitude, blood glucose monitoring system
Introduction
Hypoglycemia is a major complication in the
treatment of diabetes. Self-monitoring of blood
glucose (SMBG) is an important tool both for the
improved glucose control and in the prevention of
hypoglycemia (1). SMGB allows self-monitoring
of blood glucose when used appropriately.
However the performance of these devices are
affected by a number of factors including altitude,
temperature, oxygen saturation of blood, low
atmospheric pressure, humidity, and a change in
hematocrit value, as well as user-related factors (2-7).
In this study, our objective was to evaluate the
performance of Roche Accu-check glucometer
device compared to reference laboratory measurements in moderately high altitude. The study was
Correspondence address:
Habib Bilen
University of Atatürk,School of Medicine,
Department of Internal Medicine, Division of Endocrinology,
Erzurum, Turkey
Tel
: +90 442 236 12 12
E-mail : [email protected]
conducted at the Endocrinology Unit, Atatürk
University, Erzurum, Turkey. Erzurum with an
altitude of greater than 2000 meters is a popular
winter sports center with a long winter season.
Research Design and Methods
A total of 204 patients between 19 and 71 years of
age mostly residing in Erzurum were included in
this study. Majority of the patients had type 2
diabetes. Blood sampling for fasting blood glucose
measurements was done in the morning hours at
the laboratory of Endocrinology Unit by nurses.
The room temperature was approximately 20°C.
Capillary blood glucose was measured by “Roche
Accu-check go (serial no: GJ0492680, Roche,
Mannheim, Germany)” glucometer device, which
utilizes a photometric measurement technique based
on oxidoreductase method. Approximately 1.5 μl
of full blood (fresh capillary or venous, Li- or
NH4-heparin or EDTA) is required for measurements by Accu-check go, and the reading is
available in 5 seconds. A venous blood sample was
drawn quickly thereafter for laboratory measurement of plasma glucose with an Olympus AU 2700
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ORIGINAL ARTICLE
analyzer (serial no: 1110268). Barometric pressure
and humidity were constant. Performance of the
glucometer device was determined by comparison
with the standard laboratory methods. Patients with
diabetes complication were excluded from the
study. Patients who were treated with medications
that can affect blood glucose levels (e.g. steroids),
patients who had anemia (serum hematocrit <40%)
and patients who are receiving medications that
influence glucose measurement by glucometer
(e.g. aspirin, vitamin C) were also excluded.
Informed consent was obtained from all patients.
The study protocol was approved by the local
Ethics Committee-Institutional Board, and was
carried out in accordance with the ethical standards
laid down in the 1964 Declaration of Helsinki as
revised in 2000.
Statistical analysis
Wilcoxon pairwise two-sample test was used due
to the abnormal distribution of data. Instead of
mean, median values (minimum and maximum)
were used. Kappa constant was used to assess the
concordance between the two measurement methods with regard to the values observed below and
above the threshold level of 126. Statistical
analysis were performed with SPSS 11.5 and
medcalc 6.16.
cordance between the two measurements was
assessed with kappa constant and the concordance
rate was 47%, which is depicted by Bland &
Altman plots (Figure 1). As can be seen from the
figure, the concordance rate for values below 126
is higher compared to those above it, although chisquare test revealed no statistical difference
between the two measurement methods for values
below and above 126 (p > 0.05).
In Table 2, the relationship between gender and the
two measurement methods is shown. There were
124 female and 80 male patients in the study.
There were no differences between the two
methods in terms of gender (p > 0.05).
Majority of the patients had type 2 diabetes (Table 1),
and the effect of the type of diabetes on measurements was investigated. Accu-check go and
reference measurements did not differ significantly
with respect to the type of diabetes (p > 0.05)
(Table 3).
Results
Table 1. Demographic characteristics of patients.
AGE
Male, y (range)
49.5 (21-71)
Female, y (range)
45.0 (19-66)
SEX
Male, n (%)
80 (39.2)
Female, n (%)
124 (60.8)
TYPE of DM
The mean age was 46 years (19-71 y). Demographic characteristics of the patients are shown in
Table 1. The average blood glucose levels
measured with Accu-check go and reference
laboratory were 101.5 (71-456) and 102.5 (69-456)
mg/dl, respectively. The blood glucose values of
the overall patient group were divided into two:
those below and above 126 mg/dl. The con-
Type 1, n (%)
33 (16.2)
Type 2, n (%)
171 (83.8)
Female
Type 1, n (%)
20 (16.1)
Type 2, n (%)
104 (83.9)
Male
Type 1, n (%)
13 (16.3)
Type 2, n (%)
67 (83.8)
Table 2. Comparison of two methods for different sexes.
Gender
Male (n=80)
Female (n=124)
Total (n=204)
Measurement
method
Median
(Min-Max)
P value
0,801 (ns)
Reference
100,0
(75,0-444,0)
Accu-check
104,5
(74,0-456,0)
Reference
102,5
(71,0-456,0)
Accu-check
101,0
(69,0-432,0)
Reference
102,5
(69,0-456,0)
Accu-check
101,5
(71,0-456,0)
ns: not significant, P<0,05 is considered significant
116
0,893 (ns)
ORIGINAL ARTICLE
Table 3. Comparison of two methods for different diabetes types.
DM Type
Measurement
method
Median
(Min-Max)
P value
0,815 (ns)
DM Type 1 (n=33)
DM Type 2
(n=171)
Total (n=204)
Reference
111,0
(83,0-450,0)
Accu-check
119,0
(81,0-397,0)
Reference
100,0
(71,0-456,0)
Accu-check
101,0
(69,0-456,0)
Reference
102,5
(69,0-456,0)
Accu-check
101,5
(71,0-456,0)
0,889 (ns)
ns: not significant, P<0,05 is considered significant
the oxidase method at different altitudes and found
lower values with increasing altitude (11).
400
300
Refferance - Accu_check
+1.96 SD
238,0
200
100
Mean
0
-5,5
-100
-200
-1.96 SD
-249,0
-300
-400
50
100
150
200
250
300
350
400
AVERAGE of Refferance and Accu_check
Figure 1. Bland & Altman plot diagram of blood glucose values for
two measurement methods (within +/- 1.96 standard
deviation)
Conclusion
In this study, we evaluated the performance of
Roche Accu-check go glucometer device at a
moderately high altitude and found no significant
difference between measurements made with
Accu-check go and reference laboratory (p > 0.05).
In contrast with a previous study, Accu-check go
values were lower compared to laboratory values
(8). However in that study, the effect of altitude was
not assessed. Capillary blood glucose measurement
devices (BGMs) have been shown to produce
lower values under laboratory conditions with
constant humidity and temperature simulating
altitudes greater than 2000 meters (4), in very high
altitudes (9) and in hypobaric chamber where
different partial oxygen and atmospheric pressures
are created (10).
Also, in intensive care patients, glucometers based
on oxidase method have been reported to produce
lower glucose values (3). Moore et al. evaluated
In this study, although slightly lower glucose
values were observed with Accu-check go, the
difference was not significant. Since Accu-check
go is based on an oxidoreductase method, lower
values can be explained on the basis of decreased
partial oxygen pressure at moderately high altitudes, though the difference was negligible.
We also evaluated whether Accu-check go
measurements differ for values below and above a
threshold level of 126 mg/dl. In contrast to the
previous study in which blood glucose levels were
measured in different groups (8), we found no
significant difference.
Factors that can influence the performance of
glucometer devices include inadequate exposure to
capillary blood drop, timing errors, and user errors
(12). In order to minimize the effect of such
factors, glucometer measurements were performed
by trained personnel. On the other hand, possible
effect of other variables such as hematocrit
changes, altitude, ambient temperature, humidity,
hypotension, hypertriglyceridemia, hypoxia and
low atmospheric pressure cannot be ruled out
completely. In order to eliminate such confounding
factors patients with a hematocrit value below 40,
patients with hypotension, and patients who are
being treated with medications that can have an
impact on glucose measurements were excluded
from the study. In the study examining the performance of glucometer device at different temperatures different results were obtained (13,14). In
our study the temperature, partial atmospheric
pressure and the humidity were constant. However,
triglycerides were not measured which might have
affected our results, though this is quite unlikely.
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ORIGINAL ARTICLE
In our sub-group analyses performed for some
variables such as the type of diabetes and gender,
we found no significant effect. Particularly in
patients with type 2 diabetes, regular exercise
improves insulin sensitivity and helps to restore
normal blood glucose levels (15). However,
exercise may result in hypoglycemia especially in
patients with marginally elevated blood glucose.
Self monitoring of blood glucose is also important
with this regard. Since Accu-check go tends to
result in insignificantly lower values compared to
the reference laboratory, we believe that this
glucometer device can be reliably used for early
detection of hypoglycemia at this altitude.
In conclusion, average fasting blood glucose levels
measured with Accu-check go were lower compared to reference values, though the difference
was not significant. Accu-check go seems to be a
reliable option in the early detection and prevention of the adverse consequences of hypoglycemia at moderately high altitudes. The reliability of Accu-check go at moderately high and
very high altitudes should be confirmed with
further studies.
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